@@christoffermonikander2200 Oh hell ya! 😆 I'm actually obsessed with the Great British Baking Show, so this ticks two of my boxes for two different shows that I like 👍
Where i worked you were expected to put a .005 radius on your endmills with a diamond file when milling an inside pocket. Unless the print specified a sharp edge all edges and corners were to have a minimum .005 radius. Even a tiny radius can help prevent a fracture.
Bearings have radius, because we turn shafts and spindles with radius. They press flat on the shafts, because they understand stress. The tăng should not be as hard and brittle as the blade. A sharp corner on a glass hard piece of metal, is like scoring a piece of glass.
I made forged safety equipment for over a decade. Cutting into the radius is among one of the worst things you can do. It breaks the grainflow and weakens the shoulder substantially. This is the main reason that forged parts are so much stronger than machined. Leaving a big radius on the shoulder is important but so too is having a smooth and consistent arc. This must be forged to have max strength. Now I realize there is a big difference between the equipment I made and how swords were done historically however in modern times there is simply no reason to not use the knowledge we have.
8:51 he's framing a lot of this as belief lol he dismisses the counterarguments so brazenly and ineffectually; "but some people will argue against that because it doesn't suit their ways of making things!!!"
What kind of equipment? The principles involved in engineering one kind of tool do not often translate to other types of tools. I would also be very surprised to find that the shoulders of medieval swords were forged only and never touched with a file or grind stone. I am pretty sure the entire things was mostly forged, and then finished with stock removal techniques.
@@crookedpathforge7951 stock removal techniques were mostly hand files, they did have a pedal powered grindstone but prolonged use of it ruined the temper due to inefficient grinding causing overheating. As much work as possible would likely have been done when the metal was soft and hot as possible leaving basically just finishing and Polish after.
@@ravenpotter5131 Prolonged use of a grindstone only heats up the blade if you don't occasionally cool it in water. Many pedal powered, and river powered grindstones had a little trough full of water to keep everything cool. The grit of the stone plus the speed of the spin would carry that water up and around the entire radius of the stone wheel. You could also do what I do, which is have a bucket of water to hand to cool it. I agree that you would do as much as possible before the heat treat. Blunt Muffin is talking about interrupting the grain as the steel transitions into to the tang. From what I know it's pretty likely that folks back then used some stock removal techniques, whether files or stone or whatever, to clean and even up those shoulders. Probably just as much as a skilled sword maker would today. I also suspect that very few of even the most skilled and sought after modern makers 100% forge in their shoulder without ever touching them with a grinder. I am not even sure that forging a tang with modern steel would be stronger than a 100% stock removal tang with modern steel. Once the steel has been properly thermocycled the grain flow should no longer be an issue. I am not a doctor in metallurgy, so I may be wrong on that last point.
@@crookedpathforge7951 interesting, I didn't know about the trough on the grindstone, the one my grandfather had in his shop didn't have that, perhaps he did as you do with the bucket. I never actually saw him using it so I'm unsure. The only point I was trying to make though is the one you agreed to, I however will admit that one reason behind my point is bumpkus due to both the trough and bucket methods you mentioned.
as a swordmaker, I agree with your points, I tend to make my transitions as shallow and as radiused as possible, and I leave my riccassos unhardened, easier to bend a bent blade straight than fix a broken blade
What always leaves me flabbergasted is how many makers actually harden the tang itself. I'm not a swordmaker (yet), the longest knife-adjacent thing I made so far was a machete (and not one for sale either), and yet even I'm aware of the issues it leads to. I can see the issue with, say, feders, which are sometimes made with air hardening steel which would make the heating a bit more complicated, but with simple steels you just don't dip the whole thing, ez >
@@oliviercoen446 of course, I'm aware of this, but we're in youtube comments so i wanted to keep it as brief as possible. And same here, the only actual products I sell are knives and axes (and modern stuff - gucci table legs and whatnot but that's not something you harden)
@@Simon-et4hu thanks! I'm specifically studying Merovingian era weaponry so 5th to 8th century weapons from the continent though I'll also be looking at some 9th century stuff too, it's a period which is surprisingly poorly studied from a metallurgical perspective.
@@tobiasheal I took a screenshot of that I’ll check if there is any book on this. I am not super knowledgeable about all of this but it’s always interesting to listen/read about. I also love looking at smithing and craftsmanship!
@@tobiasheal Is there any examinable ferrous metal left from that era? I would expect most of it to be so heavily corroded that it would be quite difficult to inspect. I'd be very curious to know more about the methods you are going to use (and where any good examples of Merovingian weaponry are visible to the general public!). Best of luck with your PhD!
@@dlevi67 there's quite a bit of metal left actually, most of what I've looked at is in fairly good shape. I'll be using a whole bunch of methods to study the weapons, optical microscopy is the basic one but I'll also be doing micro hardness tests and chemical tests like SEM-EDX, LA-ICP-MS and PIXE/PIGE to characterise the metal and try and work out where it came from. In terms of where to see Merovingian weaponry, France is definitely your best bet. The Louvre and the Musée de l'armée in Paris both have a lot of good examples, so does the musée d'archéologie nationale in st germain en Laye and some local french museums have good examples too, the musée de Belfort has some impressive long seaxes. Outside of France, the Musée Royale de Mariemont in Belgium has some pretty good examples too.
The other problem with a sharp angle on the tang/shoulder area is it's a stress riser during heat treat as well, and it can easily create stress cracks that can go unseen. And these stress cracks will absolutely lead to blade failure during use. A lot of Hanwei Tinker blades suffered from this. Get a large radius there.
A friend learned about the sharp angle being a source of weakness in his 2nd year at second school about 60 years ago. He was able to impress that information into me a good few years ago.
And elsewhere...years ago, I was issued a Government contract Beretta 96D. I didn't particularly like it, but that's what we got. Among the pistol's many faults was that the angle where the frame rails (which the slide rides on) stepped down to the dust cover (the forward extension of the frame past the trigger guard, where most modern pistols have a rail for a light) was *not* radiused. According to our armorers, the early production pistols *had* been radiused there (and had had better triggers and a tighter fit on the parts as well), but once the contract was locked in, Beretta USA started cutting corners. The barrel to slide fit on mine was such that with the pistol in battery (slide locked shut on a loaded chamber) there was slight but noticable side to side movement of the barrel in the slide. Just the thing to inspire confidence! The lack of a radiused angle on the frame rail step meant that several pistols failed due to the frame cracking at that point. Every time we broke the pistols down for cleaning we were supposed to check that angle against the light to ensure it wasn't developing a crack. Fortunately, my example stayed together until it was retired and replaced with something else.
@@christopherreed4723 Good enough for government work. That pistol you were issued was the fault of the government as well as their responsibility. You were not in a hot war where your hardware would outlast you, because your life would not be long. I write this thinking that it was new when you got it and not worn out.
@@michaelharrison8036 That's an odd response. Do you figure knives don't have a tang? The addition I would have made to Chris' comment is that radius, fillet, bevel, and chamfer would be added to metal works for the heat treatment reason they mentioned, not just for shoulders on swords and knives, as well as to both remove the sharp edges so handling the item is safer and to reduce the wear on the edges of the item.
The short version is that when under load, sharp corners concentrate the stress from that load. If you add a radius to a transition you will not have such a small concentration. Imagine taking a pare of scissors and making a cut halfway through a sheet of paper and then flexing the two loose pieces like legs. You will more easily tear at the end of the cut. Now instead punch a round hole in the middle and make the same cut up to the hole. You'll notice it is much harder to rip the paper by moving the ends.
The stress relief at the shoulder of a blade is paramount! At BKS we have a gentle radius there on both sides of the blade and the majority of our guards are press fit with a stamp first that accommodates that curve at the junction between blade and hilt. If it's too sharp of an angle quite simply it will fail. Not if, but when. This isn't to say it cannot break if you do it correctly but rather that you're mitigating the probability of it happening. As Matt says no sword is indestructible.
Love the depth of your expertise, and the work you are doing with the collaborative sword productions you are involved with. I hope one day to be able to order one of the swords you helped making man.
Great video Matt. Here is another possible approach to avoiding this problem... The problem is that a crack can form at the stress concentration in the sharp corner where the tang is meeting the blade. As the sword is used the crack will work its way across the region where the tang meets the blade and eventually the tang breaks off. Assuming that no crack has formed yet it is possible to take a drill (preferably using a drillpress and a secure vice) and drill two small holes roughly centered at the points where the tang meets the blade. One would expect removing that material makes the sword weaker however the radius of the drill hole will reduce the stress concentration and thereby avoid the formation of cracks. If there is already any evidence of a crack between the blade and tang it is best to get another sword. The sword may seem perfectly fine an instant before it snaps. Annealing a blade that has already developed a crack will not prevent the crack from growing through the metal (though in fairness it might slow it down a little...) Obviously the best solution is to have a good radius at the blade meets the tang.
I have broken / tested a lot of knifes over 25 years in my job in a knife factory (Brusletto, Norway). Even a smal radius at the tang make a big diffrence. And also the grinding marks is in the lenght of the tang. Sorry ,horrible english.
Your English seems fine to me. We would call the plural of knife "knives" with a v, but who cares, as long as we understand? Also, many English speakers don't do well with written English either. I feel like many people who use English as a secondary language actually use better grammar than native speakers as often as not.
I have learnt to my cost in the past that leaving a very angled tang to ricasso...not a good idea. I now always round the juncture from tang to blade and haven't suffered the old problem of snapped tang occurring. Love the videos and await the next..!
I'll say this (as a relatively competent smith) - it's a bloody sight easier to peen a tang over (assuming you don't have a torch) with mild steel or wrought iron, if you bugger it up after the first heat. For longer knives and swords, I don't harden tangs and bases of blades (ricassos, if you like) either.
100% agree. Id say about 70% of the modern repros that ive had fail on me have been for those very 2 reasons. They snap at the transition, inside the the hilt or the pommel snaps off.
At the sword smithy where I work. we don't quench the tang, when I first started working there I was surprised by it, but no one has complained about our blades breaking since I have been doing it like that. Also makes it a darn sight easier to peen the back end.
These are all very good points. I haven't stepped up to making swords or long blades yet, but I remember one of the first hidden tang knife videos I watched in the old days of early TH-cam was of a smith going step by step through his heat treatment process and after straightening his blade he drew back the temper of his tang by locking the blade in a vise with wet rags around the blade and using a torch to draw the tang back from martensite (hard) phase. It's a nifty trick and I use it for my smaller knives that usually get dunked all the way into the quench. You can even do this to the very spine of a blade to give it a bit more flex if you're really careful and use a low flame, just watching the oxidation colors to creep up on a higher temper. That's very tricky though, I'm not going to lie.
Radii in corners comes under design geometry. The metallurgy is a separate issue. Surface finish and the 'lay' of machining marks are also critical in stressed areas. I chamfer and buff all edges in this area to remove any micro cracks along the edges and reduce or remove any deep scratches running across the blade-tang. Scratches running length-wise are less of an issue. Remember the de Havilland Comet.
Good point Matt, in a rapier competition my blade snapped at the tang, which had square shoulders while parrying a cut. I was hit by my own blade and then the opponent's, a double hit and I got all of it.
Being a knife (and occasional sword) maker, I do all those things, and they were taught to me when I was learning the basics. It varies as to whether I quench the whole piece or not but I will always use a torch to anneal the tang, in the case of knives, so I can drill a hole for the pin(s). Good call though, bringing attention to this stuff is important.
Sam From Castille Armory chiming in, and thank you Matt! This is all absolutely legitimate information and realistically it doesn't matter if you have a large industrial setup like we do or you are a one-off sort of boutique shop. If you are making swords for any kind of use with exception pretty non-functional wall hangers, the tang needs to be able to stand up to abuse and shock. As Matt mentioned to start, putting ANY kind of radius in the tang/blade shoulder junction is a good idea. Realistically the more radius you can add, the better. We try to standardize something at least a 2.7mm radius (0.10") wherever possible. I do want to note that the lighter the blade, say modern epee blades, the less it really matters as the stress and shock that a blade like that is going to see is far removed from say a heavier arming sword blade. It's still a good idea, you would be surprised what a tiny radius will accomplish in the heaviest Buhurt blades. Now, mass manufacture blades of mono steel in the modern fashion, 5160, 6150, 9260, 80crv2, 1075 and 1095. We harden the raw bar first then use waterjet technology to cut the blade blanks from the bar. These hardened blanks are then ground to the diamond distal cross sections that give them flex and weight distribution as desired. It is an easy way to mass produce blades and not have to deal with a lot of blade straightening; the heat treat process usually will incur some degree of warpage especially edgewise "sabreing" if the blade is pre-ground. This means that the tangs of these (our) blades are full hard and therefore have not only the issue of being brittle, unmovable and having little shock absorbtion as Matt explained, but an additional issue that Matt didn't cover. An issue that plagues modern manufactured fencing blades- Thread! Threaded tangs have been standardized among modern blade makers along side peened tangs. Threaded tangs are nothing new as Matt demonstrated with the antique blades he presented in this video which were threaded. They offer modularity first and foremost so switching out hardware is easy, say if the blade breaks or if a practitioner wants multiple blade options for a specific set of hardware. The issue with full hard tangs is that threads can't be cut on them, the steel is nearly as hard as the cutting dies. There are two ways that manufacturers deal with this. The first is welding thread to the tang. This method is fairly common. While it is quick and easy, if done without further processes, welding high carbon steel is wrought with issues. Microfractures are the biggest side effect of welding high carbon steel. Essentially when welding carbon steel, you're hyper heating and hyper cooling a small area. The surrounding boundaries of the weld draw the heat down quickly after being heated to temperatures over 870 C (1600 F). The thread stock, a different alloy- often low carbon steel, expands and contracts at different rates than the tang steel during this process. This uneven expansion and shrinkage results in tiny fractures within the weld junction. At this point the High carbon side of the weld is very hard and brittle and will break quite easily so there needs to be a annealing process to soften the weld area. Once this is done, the welded area will be much stronger and will bend rather than break BUT those micro fractures are still present. Preheating the weld junction before welding can greatly reduce the occurrence of these tiny fractures. If you're a long time practitioner, you've probably experienced broken thread right at the tang, thread junction. The other method for dealing with threaded tangs, which we now use and have for nearly a decade, is to anneal the entire tang region using an induction forge and cooling the tang slowly in vermiculite. This process, usually 3 cycles, draws down the hardness gradually and evenly along the tang and makes the threaded portion more than soft enough to cut threads directly. It also drops the hardness down in the tang/blade shoulder region reducing the risk of breakage in that area. This process results in a very strong tang portion and the strongest thread section that can be afforded.
Thank you. I'm neither a sword maker nor a sword buyer but I do find this topic interesting. It's easy for us to deceive ourselves and believe we "know so much more than they did" and end up with cosmetically better but functionally worse products.
A lot of this isn't necessarily a "we know better now" thing. Most makers know how it SHOULD be done, but doing it the right way is usually much more expensive. Manufactures are cutting corners in production processes in order to save money. Forge welding on a low carbon tang is a whole new series of manufacturing steps that will nearly double the production cost. Even just annealing the tang on a mono-steel blade is an additional time consuming process that adds up to serious money over hundreds or thousands of blades. Cost cutting in almost any field results in inferior products. Conversely, most people aren't willing to pay the premium to have things made properly.
I'm a mechanical and aerospace engineer:). As for the tangs. I believe the soft iron is used in the tang to make it easier to mount hilts. And no matter how it's heat treated, there is no chance that tang will harden. If they knew the heat treat process was more controlled and guaranteed no hardening of the tang, they would have kept it one piece. Unhardened is just as tough and bendable, if not more so, than iron, the only real difference is the chance of it being hardened. Deltin blades are 6150 steel, same as what I use. It has a very large amount of bending before snapping if it's properly heat treated. I always soften the majority of the tang, but it does depend on blade geometry. The problem with a lot of tangs in modern swords is the stock is too thin for a soften tang.
If you look at a hardness vs toughness vs tempering temperature chart for steels, they often have a toughness peak somewhere in the middle of the tempering range. That should be the target temper for the tang, not full hard or full annealed.
Just a quick point; you _can_ harden low-carbon steel, but not brilliantly. It isn't purely done through heat treatment either. You need to use high concentrations of cyanide-containing substances in which to 'quench' them. My father used to do this with low-carbon files for woodwork (not metalwork) and he absolutely swore by the process. In those days it was also much easier to get hold of the cyanide--he would even use the dirty liquor afterward to kill dandelions around the garden! I seem to recall him telling me it was only 'case-hardening' though, which means the hardness does not go all the way through the chunk of metal but just forms a 'crust' on the outside. This gives very specific performance characteristic which my dad was after. Likely for combat use though it would be far from ideal. As an aside--the sword-making process depicted in great detail at the beginning of both the film of 'Conan the Barbarian' and especially the novelisation would have resulted in a form of case-hardening as well--only a thin layer of cast-iron would have been converted into (low carbon) steel. The 'Father Sword' that was made in this way broke against high-technology Atlantean steel, which assuming the Atlanteans knew as much about how to make steel (or more?) than we do would have almost certainly happened in real life as well. The big difference in modern steels was the introduction first of the Huntsman Process and latterly the 'Bessemer Egg' convertor--these were then followed by 'cupola' designs and eventually 'reverberatory' technology and beyond. The steel that a modern foundry in Sheffield (if you can find one still in business!) or any other steel-making centre can churn out today is the very best quality that has ever been produced in human history. All the myth-making and fantasy guff about pattern-welded 'Damascus', 'Wootz' or Japanese sand-steel is nonsense. We can make it quicker, better and in hundreds of ton quantities, no fetishistic folding or prayers to the Buddha required! *EDIT:* In regards the differential hardening approach I wonder if you could apply the Japanese technique and cover the tang with clay so it cools more slowly than the blade resulting the same hard blade, soft tang but done in one step?
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It would be interesting to test if tangs made out of iron and welded on, or made out of not hardened steel, really help with reducing the hand shock, all other things being equal.
excellent vid! i apply these concepts to the swords and knives i make right now. however it would have been better to zoom in with a contrasting background. i knew exactly what you meant but couldn’t see any of the details you picked out very well at all.
Thanks for the video, Matt, it is indeed an overlooked but important detail. One of my clubmates broke a sword from a popular HEMA manufacturer at the tang/edge transition point just by swinging it hard with poor edge alignment.
As a machinist of some years, the lack of a fillet ( the correct term for a radius or rounded _inside_ corner) was the first thing I noticed on that blade. I knew that would be the first thing you mentioned.
As a bladesmith all i can say is you can have exactly what you want as long as you can pay for it but if you expected to get everything for $1000 you are dreaming. Something simple like a radiused tang adds hours to getting a very tight fit to the guard. It isn't that bladesmiths are ignorant of the best way to build something. Bladesmiths have to build to a price people are willing to pay and that leads to compromises.
Following your instructions I just told all the swordsmiths I know about this. It took no time at all. Not a maker, but I still found this interesting.
Love videos like this, more please! Was looking in to investing in another sword recently. Was surprised by the difference in ricasso thickness between suppliers, kvetun came out the best in this regard...
I recently bought some used farm implements and the previous user modified some 3/4 inch plates and added a 90-degree notch to accommodate aftermarket hydraulic rams, needless to say, 2 acres in, the tab snapped right at the 90-degree notch. just wanted to say, the information is applicable beyond swords lol.
I had a 1860 saber break when I was going through cutting fruit while mounted. It was a replica, but still when we took it apart the tang was just tiny compared to the originals.
I've taken a small round file to some of my swords tang shoulders after learning this. I have been fairly rough on many of my swords but only broken one before. It was not a good sword any way. But with some of my good swords I've cut pine tree saplings, hard bamboo, 1/2 inch plywood, thin pots & pans, etc. Given some of my swords I've had since the mid to late 90s & they still survive...well that's why I consider them good.
@@vyor8837 Not cutting, filing. And it's only bad if you do it incorrectly. The file I use is about half as thick as a pencil. Slight rounding the angle, then leveling of the shoulders & tang to match removes minimal material & eliminates the right angle that is certainly a weak point. The key is to remove as little metal as possible. And last sword I did only required removing less than 1/2 millimeter of material. It's also best if the tang is pretty substantial at the shoulders.
I very often use mild in a tang with an interlocking forge-weld. I've been given crap about this, but I still continue, and I never harden the tang even where I don't.
Mechanical engineer by training here, just checking in to say that Matt has an excellent practical grasp of how metal behaves under stress. That was a very good explanation of stress risers and how softer metals in critical areas can prevent breakage. Brittle metal is bad.
You can find the charts for the differences of the shoulders and radius under mechanics of solids. Hardening the tang makes it harder to thread, drill through, or peening if doing after hardening. Tempering does decrease the hardness but it will still be fairly hard. Annealing/ normalizing like what he mentioned would make it easier to do post processing. And make it softer and allow it to bend not break like he mentioned as well. Very good video and interesting look at historical and modern sword making
What you said about the tang material makes practical sense. A sword that breaks midway up the blade it's still usable. If it breaks at the guard is only good for throwing at someone.
Not quenching all the way past the ricasso can cause an issue from a looks perspective where the metal won't polish the same in the hardened/unhardened regions. Pattern-welded steels will show this clear as day after etching. I agree though, if you buy a sword you're going to beat up, no harm in taking it apart and heating the joint out to a pale blue temper to soften that region. Bonus is it will make filing in some radius there easier.
I solder the cross guard to the tang. This results in the tang tearing rather than snapping, and when fighting with them you can feel the tang tear and stop before your blade flies into the audience....
You left out one of my pet peeves, welding a piece of threaded rod on the end of the tang. If done properly it’s at least as good as simply threading the end of the (unhardened) tang but I’ve seen welds that look like saltwater “corrosion welding” and fail easily, and the threaded rod commonly used seems prone to stretching and consequent stripping of the threads. Otherwise I take a little pride in accurately predicting your actual points. See? Some of us do pay attention. 😃
It's interesting that iron / mild steel tangs were welded on because many years ago I made some Anglo Saxon pattern welded blades and I forge welded on a mild steel tang to get a little more strength in the tang. Good video, I learned quite a bit from it. Thank you.
I don't make swords. I don't own a sword. I do play tabletop RPGs. This was a very well done video on the subject. To the point and easy to understand even for complete newbies like me. I certainly liked and subscribed. After I leave this comment I'm going to do a dive in on your channel.
Good advice, when I make a sword I follow these very important principles. I would definitely not harden the tang or try to weld it. I have seen that go badly.
I'm just starting blacksmithing, and was thinking about this exact thing - the sharpness of the radius of the shoulder. Thank you for validating my thoughts on this! The soft tang and ricasso thickness was a new one for me though. 🙂👍
In the past it would've been easier to find someone relatively local to do minor repairs like a bent tan or w/e for a reasonable price so that's one thing to consider. Having something that won't need any repair work done unless it's a major event might be preferably for a layman.
So one of the few things I was taught to do correctly making STAGE swords was the cutting off of the thin tang and welding a nice thick mild steel one back in? The boss had learned to make them that way because of how upset stage managers got when a sword broke and the managers had not rented an extra as a back up.
The transition between blade and tang, yep, that is the point of failure that I have experienced as well. Sparing with a mate, my whole blade went flying, that was the exact breaking point. A third mate was missed by the flying blade by about a foot.
I've always seen blades break at the tang, and indeed that always seemed like a fragile region to me. I've made a few crossbow steel bows, and when everything flexes, it stays together. If you stress only one part tho, or make it with a weak point, all the tension is going to flex this point instead and it's gonna shatter on you. So for my knives and swords, i usually only quench the blade, and the tang never even touches the water. Also beacause i only use a charcoal forge, i can avoid heating up the tang part altogether, so even if it gets quenched, it doesnt actually hardens. I don't think i've ever seen my blades break at the tang, but the heavy distal taper makes the blade bend instead of the tang part, so that helps too.
As an engineer but not a sword maker, I would be inclined to make the thickness taper rapidly near the tang and then make the tang a uniform thickness. The reason is to increase strength just where the leverage is the highest .
that was a great video I've always wanted to see what the tang looked like on a 1796esk blade. I wonder if you would be I interested in doing a video on ww2 British and American machete typology. I notice the legitimatus Collins and co machete seem to differ from the onterio machete. certain variants of Collins have a slight upward curve which for me looks really nice. the onterio machete is very workman like and I belive still supplies the US military today. (and that's the full extent of my knowledge lol ) then you have the British machete aswell. many thanks Mark kiely
THANK YOU! Every sword making video I watch has this mistake. They also usually make the tang way too narrow/weak. Huge mistake unless it's only for display. In which case, I wouldn't own it.
Another (not particularly useful) perk of mild steel tangs is the resistance to rust, since the higher carbon content the easier it rusts. I can see this being a useful perk in tropical colonies where moisture gets everywhere, while cleaning rag - not necessarily As you probably know due to your background the difference between high carbon and iron preservation in the same medium is visible with a naked eye, and the oxidation slows down with time in case hardened objects, as opposed to what we're used to in our car frames
If increasing bar stock thickness is cost prohibitive, increasing the profile width of the tang will at least give you the same cross sectional area. Though the second moment of area (a property relating to resisting binding in a given axis) won't be identical.
This is very interesting! I never imagined that they would change the type of material from the blade to the tang. The 10mm-thick ricasso is also interesting in terms of puting the PoB close to the guard.
Also when the tang connects to the blade and that portion breaks It's often times called shearing Shearing metal is something to know As it is the definition of what happens
Heat treating the tang is purely a modern thing, in all the older books I've read about making blades and swords they only heat treated the blade, typically as you described. Definitely not even all the way to the tang. True in knifes as well. As for the welding different materials it is undoubtedly more difficult to do, and most modern craftsmen don't think in terms of forge welding either, so they'd most likely do a butt weld as opposed to a cleft weld hammered shut. I think the butt weld would undoubtedly be a weak point in a way the lapped or cleft weld isn't. I think as long as they avoid heat treating the tang this wouldn't be much of an issue though.
It would be extremely difficult to butt weld a sword tang onto the sword, unless you did it at a stage where the material was still in a thicker billet form. I'd be really surprised to see it done. The Viking Era swords I've seen (from books) have a lap weld maybe an inch or two before where the tang itself starts. I really think that forgewelding used to be thought of the same way as we think of tying our shoes. Which is to say not very often. Not because it was difficult, but because it was such a simple and routine part of making just about any common item. I like your comment about how modern craftsmen don't think about it in the same way.
Paused at 9:26The tang has a Soft wrought/iron handle. I don't forge weld handles, but I do soften up them. If you know what you're looking at, you can see the line of the weld. You can harden mild steel to a degree, but it's not going to have as much martinsite as Higher carbon.
Knew what you were going to say before you said it! Same thing applies to axles - people have been killed by sharp internal shoulders propagating cracks leading to shear fractures. 👍🏻
Great video, though you didn't mention what I have found to be the even worse flaw in modern blades, especially very cheap ones (but not always). Sword makes really should not make a tang by mig welding a thin bit of threaded rod to the end of the blade or partial tang. I have seen it most often where the forged tang is only about an inch long, and you then have a m4-m6 length of threaded rod welded (badly and presumably not tempered afterwards) on to make up the extra length and make fitting a pommel easy. It doesn't take much at all to make that weld snap, and then the whole blade goes flying off, leaving the hilt to fall apart in the wielder's hand. I have mostly found this in very cheap swords that are only really meant for display, but I own two swords sold by different companies that were sold as reenactment fencing blades that have done this too.
Awesome video, as always. I'm hoping to start making blades (knives and swords, purely as a hobby), and this is really interesting to me! However, with all your videos I've watched, I never noticed the aquarium on your cabinet. What do you have in there? A snake?
Good analysis, thank you. So, one reason a maker might desire a hardened and tempered tang/ricasso junction rather than annealed, is that a bent junction is not very useful. What are you going to do with a significantly deformed sword? Bend it back and it will have become much less tough. Properly heat treated steel of appropriate composition is astonishingly difficult to break (in appropriate dimensions) at the junction. Civilization rides on heat treated steel springs, and while they do occasionally break, mostly they work as engineered. Consider the very thin edge impacting armour and bone at velocities perhaps 150 fps versus the handheld, beefy tang junction which is much slower, and somewhat supported by the handle, and I think the real issue is the edge/s and the tip mass in overstrikes, or main mass in hard tip strikes. I would certainly like to see evidence of sword failure at the junction when the steel is properly heat treated and appropriately proportioned and no flaws (slag inclusions for example) present... it would be fascinating.
Interesting topic and well done. I wonder if the tang's thickness could have been a way to balance some of those older blades. Great explanation of why and why not to do it. I know on the saber I have, it is the actual thickness of the blade spine all the way through to the pommel where the guard attaches. I've been told it is a civil war Ames blade made in Japan, but I can't tell because my father covered the entire thing in orange shellac after getting it from the mud near the James River in VA of the USA. The wire wrapping on the wood is gone except for a small piece and no scabbard was found. I've never found an example like it. I was told by someone else it was not from the civil war at all, just stamped when the owner entered the war. Take Care and Stay Safe.
Amen - great tips. Another interesting upload.....they really did make weapons work as weapons back in the days of swordplay that your life depended on. Before you grind or cut your tang shape from bar stock, you can theoretically "upset" the metal in that area to thicken the metal at that junction. Better still, forge your tang rather than use a metal removing method and it'll be problem solved.
I'm a tool smith and sometimes that means I make knives and swords. I always start with a hay rake that's about a hundred years old. When the blade is done I forge weld a wrought iron tang and she's got the rounded bit instead of a right angle. That's how I've always done it. Also what you described is not anealing, its normalizing. To aneal you bring the work piece up to a critical heat( non magnetic) and then you bury the piece in wood ash. That allows the piece to cool very slowly and makes it dead soft. With normalizing, you bring the piece to a critical heat and allow it to cool in a spot in the shop that doesn't have a breeze so that it doesn't air cool. Its not dead soft but its not hard either. One will do this several times to get the grain size smaller and tighter before you do the heat treatment. If you are making a sword out of all high carbon steel than you are right. Don't quench the last couple of inches above the tang. You already normalized the entire piece several times so just put it out of the way and let the tang cool. If you want an anealed tang then bring the entire piece to critical heat, quench the blade except for the last couple of inches and then quickly bury the tang end in wood ash. Depending on the use of the sword I would do either. However like I said, I prefer to forge weld a wrought iron tang. My tools and blades come with a life time guarantee barring stupidity. And since I'm not fond of making swords, I do it right the first time. Iron tang that has a radius where the tang meets the blade. What we call the weak part when the tang is at right angles is a cold shut. There are several things called a cold shut and stress riser works too in this particular situation. Thanx for bringing this important point to those that don't know better. OZZ- owner of Kalapooia forge.
Totally agree! I always steel leave tangs soft, with radii, and thicker, although admittedly I've never forge-welded in a separate mild steel or iron tang. For my bronze blades this isn't an issue as they are cast full tanged and flanged :-)
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As a sword and knife smith I'd add one other thing (sorry if I dont use right english words - not a native speaker) - if you have the thick junction part, do a distal taper on tang. If you leave it 8 - 10mm thick all the way, its weaker than when it goes down to something reasonable like 4-5 mm. Its about vibration - if you hold it by the jucntion and hit it with something, blade must sound one nice tone and tang other, higher. If its just a lump of metal, the vibration from blade will stop mostly at the junction where it will build up stress fractures. The handle and the pommel will act as a nice dampener cushion, but the blade-tang geometry must let them do that.
FINALLY SOMEONE ADDRESS THIS!! The Companies of Lower End Swords Always Make Handle and Tangs Terrible.. . You only One That Has Called this out FINALLY!! I been asking reviewers to Look at Tang & Handle..Ive watched all the Sword Channel Guys. Your the Only Guy That Has Finally Done This!!
This is the main reason I tend to Cutler together my own swords from a bare blade: I've then seen how the shoulder looks, that it has a proper radius and is't sharp. Also then I can see that the tang is wide and also not tempered hard but soft enough to peen. The next thing is the screw end. I understand for interchangeability from sharp to blunt on your favorite rapier handle you'd want this. For target cutting though I would advise against a tang that is held in with a nut (if the screw end of the tang is tempered). Because that too is a weak point. If you use a blade like that attach it further with glue.
I build a few swords and I never had a sharp angle because I always used a full Tang never such an angled and pointed Tang to put a hilt on . I always wanted as much support under it as possible.
Cable tang on the Natchez and Laredo Bowie's from Cold Steel are a modern way of doing the softer tang material , basically the handle will die long before weld and cable tang will snap off.
Another great vid, somehow after years I wasn’t subscribed?! Great info, very clever insights. When you said you’d been playing with swords for 20/30 years I started trying to figure out your age, and I honestly can’t. Are you the count of monte christo?
Hi! Professional cutler here, I have to say I agree completely with these points, and have a few more myself. Shock transfer is a huge issue if you are going to be using any cutting tool, for any lengrh time, in a task that involves impact. Having a proper geat treat process, good transitions, properly radiused transitions and a soft tang all make a huge dofference to hand shock. Its true in swords and especially axes. That single, homogenous, hardened and tempered piece of steel is going to transfer shock directly into the hand of the user and cause soft tissue damage, as well as, potentially, snap the tang off at the guard or inside the hilt. A point you tou hed on very briefly, but I think warrents a little additional attention, is the welding together of dofferent metals in the tang. I am very much of the opinion that there are only two ways of doing this, a right way and a very wrong way. Scarf welding, or any of its variations, gives a lot more surface area of the two metals a place to touch, allowing for that transfer of shock to occur over a larger area. In turn, this should minimize stress put on any spots where the weld isn’t perfect and also, dispers that shock a little more beforw it transfers to the hand. Butted welds on the other hand, tend to involve very minimal amounts of surface space touching and frequently also involve very dramatic changes in material size. In my experience, this tends to multiply felt shock a great deal ans concentrate that stress directly at the weld, which seems to almost always lead to faulure of the tang.
17:02 That Alexandrian blade must have a monster thick tang. 4.5 Cm.. Wow.. I know it is a slipup. But a bit fun to imagine a blade with 4.5 cm thick tang
I'm sure there was some understanding that a bigger radius on the join was stronger in history, but it wasn't really until the 20th C that the idea of stress risers really became known. It's especially clear what's going on with visualization tools like piezoelectrics. If you have a blade you want to add some radius too to add strength, a non-intuitive way to add strength is to cut the (partial) circle into the corner. probably in the direction of the blade, seeing you likely don't want the tang to get thinner. Contrary to expectations, this reduction of stress risers more than compensates for the lost material. It's a pretty common technique when you'd like to match up parts as well, where a concave rounded corner would get in the way.
I wonder. Would there be any practical issues to making the blade taper into the tang very gently, so that there would not be a clear, distinct shoulder at all? Granted, it would mean that you'd have to have a portion of the too-wide tang exposed since it would not fit into the hilt construction, but blades with ricassos are an entirely normal thing. (I'm actually wondering if there is any reason that this would weaken the blade construction. Ostensibly, the thinner portion of the blade will be exposed to any and all of the same stress anyway, whether it is exposed or a shoudler, and it would be very unlikely that someone could cut through the somewhat narrower base, or otherwise notably damage it any easier than just snapping a structurally weak blade in the first place.)
Having a shoulder makes handles and especially guards much easier to fit and assemble. And you also don't need that much material in the handle, the only job it's doing is holding the handle to the blade, and as long as it does that securely that's enough. If you look at katana tangs they are very similar to what you describe but they still have a shoulder because it's very useful.
@@UnbeltedSundew Yes, I wondered about that. It's certainly true that no shoulder at all would make it harder to get a tight fit for the hilt assembly.
About the Indian cavalry blade: the angle is actually very obtuse. As this is a single edged sword, it's the angle on the same side as the spine that matters. The one on the side of the edge is straight, but this is simply to allow the tang to be broader than it would otherwise be with obtuse angles on both sides.
really good video and i am glad i figured the angular part of the tang on my own from the experience, but i have a very important question. I am currently putting together a sabre and what i would like to know is the construction of the hilts, baskets and the different types of these hilts and how are they put together. Another thing i would like to know is the best way to secure the entire handle. Should that be done with riveting the end and securing it till the end of times or should i go with the thread as shown with the blade at 7:25. For some reason i always think of riveting as the only right way and threads to be "modern and not so classic" but after seeing this antique blade with the thread on it, i am not sure anymore. PS. When it comes to sabres i was always interested in the entire construction of the entie handles and how it was made and since you are very familiar with sabres i hope you could help me. Anyway amazing video and thank you :)
6:50 there is another option of giving more strength to this part you are talking about. Don’t cut the angels out on the same level. That gives you a bigger cross section without the use of more material. And if u normalize the „cuts“ in relation to the more ore lesss „diagonal“…. Sorry I am no native speaker, but the trick is the same with tank armour, just angle it. Make a small drawin and you will see, … add some vectors for the possible forces …
I got a totally awful wall-hanger from Corrado Cutlery in Chicago a whole bunch of years ago. It's that tiny little tang, with the threaded rod welded on for the pommel knob. The damn thing was only good for hanging on a wall, because the tang could not take the shock of hitting anything with more than a fly-swatting force. I think that corner is angled instead of properly radiused.
I haven't made any swords but I've noticed that as well if it is cut in flat instead of cut in and then filed in it'll cause more stress needs to be slightly angled up from the blade
This makes me want a British version of Forged In Fire… Tod Cutler can be the new Dave Baker, and Matt Easton can be the Doug Marcaida 😆
The Great British Making show
I would watch the hell out of that show...
@@christoffermonikander2200 Oh hell ya! 😆 I'm actually obsessed with the Great British Baking Show, so this ticks two of my boxes for two different shows that I like 👍
Would be really funny hearing stuff like "Well its not a finished knife then, insn't it? Cheerio then, jog on."
Have to get Joerg as the new Jay
"You should leave R (RADIUS) in the angle to avoid metal weakening during wear". We, CNC machinist and engineers call it RADIUS.
Where i worked you were expected to put a .005 radius on your endmills with a diamond file when milling an inside pocket. Unless the print specified a sharp edge all edges and corners were to have a minimum .005 radius. Even a tiny radius can help prevent a fracture.
@@angryroostercreations5194 In railroad parts working under high stress we have to leave anti wear and tear R3 (3mm - Europe).
Bearings have radius, because we turn shafts and spindles with radius. They press flat on the shafts, because they understand stress. The tăng should not be as hard and brittle as the blade. A sharp corner on a glass hard piece of metal, is like scoring a piece of glass.
No stainless steel is good for sword lenght blades. Not even a long knife. I have thought about brake die, Mirralloy, and good ole spring steel.
@@everettplummer9725 Bearings have a Chamfer.
I made forged safety equipment for over a decade. Cutting into the radius is among one of the worst things you can do. It breaks the grainflow and weakens the shoulder substantially. This is the main reason that forged parts are so much stronger than machined. Leaving a big radius on the shoulder is important but so too is having a smooth and consistent arc. This must be forged to have max strength. Now I realize there is a big difference between the equipment I made and how swords were done historically however in modern times there is simply no reason to not use the knowledge we have.
8:51 he's framing a lot of this as belief lol
he dismisses the counterarguments so brazenly and ineffectually; "but some people will argue against that because it doesn't suit their ways of making things!!!"
What kind of equipment? The principles involved in engineering one kind of tool do not often translate to other types of tools. I would also be very surprised to find that the shoulders of medieval swords were forged only and never touched with a file or grind stone. I am pretty sure the entire things was mostly forged, and then finished with stock removal techniques.
@@crookedpathforge7951 stock removal techniques were mostly hand files, they did have a pedal powered grindstone but prolonged use of it ruined the temper due to inefficient grinding causing overheating. As much work as possible would likely have been done when the metal was soft and hot as possible leaving basically just finishing and Polish after.
@@ravenpotter5131 Prolonged use of a grindstone only heats up the blade if you don't occasionally cool it in water. Many pedal powered, and river powered grindstones had a little trough full of water to keep everything cool. The grit of the stone plus the speed of the spin would carry that water up and around the entire radius of the stone wheel. You could also do what I do, which is have a bucket of water to hand to cool it. I agree that you would do as much as possible before the heat treat. Blunt Muffin is talking about interrupting the grain as the steel transitions into to the tang. From what I know it's pretty likely that folks back then used some stock removal techniques, whether files or stone or whatever, to clean and even up those shoulders. Probably just as much as a skilled sword maker would today. I also suspect that very few of even the most skilled and sought after modern makers 100% forge in their shoulder without ever touching them with a grinder. I am not even sure that forging a tang with modern steel would be stronger than a 100% stock removal tang with modern steel. Once the steel has been properly thermocycled the grain flow should no longer be an issue. I am not a doctor in metallurgy, so I may be wrong on that last point.
@@crookedpathforge7951 interesting, I didn't know about the trough on the grindstone, the one my grandfather had in his shop didn't have that, perhaps he did as you do with the bucket. I never actually saw him using it so I'm unsure. The only point I was trying to make though is the one you agreed to, I however will admit that one reason behind my point is bumpkus due to both the trough and bucket methods you mentioned.
as a swordmaker, I agree with your points, I tend to make my transitions as shallow and as radiused as possible, and I leave my riccassos unhardened, easier to bend a bent blade straight than fix a broken blade
Great foresight
What always leaves me flabbergasted is how many makers actually harden the tang itself. I'm not a swordmaker (yet), the longest knife-adjacent thing I made so far was a machete (and not one for sale either), and yet even I'm aware of the issues it leads to. I can see the issue with, say, feders, which are sometimes made with air hardening steel which would make the heating a bit more complicated, but with simple steels you just don't dip the whole thing, ez >
@@oliviercoen446iron would be terrible for swords.
@@oliviercoen446 of course, I'm aware of this, but we're in youtube comments so i wanted to keep it as brief as possible. And same here, the only actual products I sell are knives and axes (and modern stuff - gucci table legs and whatnot but that's not something you harden)
@@Sk0lzky Still I bet those legs are deadly! Ok not useful to the conversation I know I couldn't help myself.
This is really useful stuff, I've just started a PhD on the archaeometallurgy of Early Medieval swords and this video gave me a lot to think about.
Damn that sounds like a worthy endeavor! I just learned a new term and my curiosity is piqued!
@@Simon-et4hu thanks! I'm specifically studying Merovingian era weaponry so 5th to 8th century weapons from the continent though I'll also be looking at some 9th century stuff too, it's a period which is surprisingly poorly studied from a metallurgical perspective.
@@tobiasheal I took a screenshot of that I’ll check if there is any book on this. I am not super knowledgeable about all of this but it’s always interesting to listen/read about. I also love looking at smithing and craftsmanship!
@@tobiasheal Is there any examinable ferrous metal left from that era? I would expect most of it to be so heavily corroded that it would be quite difficult to inspect. I'd be very curious to know more about the methods you are going to use (and where any good examples of Merovingian weaponry are visible to the general public!). Best of luck with your PhD!
@@dlevi67 there's quite a bit of metal left actually, most of what I've looked at is in fairly good shape. I'll be using a whole bunch of methods to study the weapons, optical microscopy is the basic one but I'll also be doing micro hardness tests and chemical tests like SEM-EDX, LA-ICP-MS and PIXE/PIGE to characterise the metal and try and work out where it came from. In terms of where to see Merovingian weaponry, France is definitely your best bet. The Louvre and the Musée de l'armée in Paris both have a lot of good examples, so does the musée d'archéologie nationale in st germain en Laye and some local french museums have good examples too, the musée de Belfort has some impressive long seaxes. Outside of France, the Musée Royale de Mariemont in Belgium has some pretty good examples too.
The other problem with a sharp angle on the tang/shoulder area is it's a stress riser during heat treat as well, and it can easily create stress cracks that can go unseen. And these stress cracks will absolutely lead to blade failure during use. A lot of Hanwei Tinker blades suffered from this. Get a large radius there.
A friend learned about the sharp angle being a source of weakness in his 2nd year at second school about 60 years ago. He was able to impress that information into me a good few years ago.
Same with knives.
And elsewhere...years ago, I was issued a Government contract Beretta 96D. I didn't particularly like it, but that's what we got. Among the pistol's many faults was that the angle where the frame rails (which the slide rides on) stepped down to the dust cover (the forward extension of the frame past the trigger guard, where most modern pistols have a rail for a light) was *not* radiused. According to our armorers, the early production pistols *had* been radiused there (and had had better triggers and a tighter fit on the parts as well), but once the contract was locked in, Beretta USA started cutting corners. The barrel to slide fit on mine was such that with the pistol in battery (slide locked shut on a loaded chamber) there was slight but noticable side to side movement of the barrel in the slide. Just the thing to inspire confidence!
The lack of a radiused angle on the frame rail step meant that several pistols failed due to the frame cracking at that point. Every time we broke the pistols down for cleaning we were supposed to check that angle against the light to ensure it wasn't developing a crack.
Fortunately, my example stayed together until it was retired and replaced with something else.
@@christopherreed4723
Good enough for government work.
That pistol you were issued was the fault of the government as well as their responsibility.
You were not in a hot war where your hardware would outlast you, because your life would not be long.
I write this thinking that it was new when you got it and not worn out.
@@michaelharrison8036 That's an odd response. Do you figure knives don't have a tang? The addition I would have made to Chris' comment is that radius, fillet, bevel, and chamfer would be added to metal works for the heat treatment reason they mentioned, not just for shoulders on swords and knives, as well as to both remove the sharp edges so handling the item is safer and to reduce the wear on the edges of the item.
The short version is that when under load, sharp corners concentrate the stress from that load. If you add a radius to a transition you will not have such a small concentration.
Imagine taking a pare of scissors and making a cut halfway through a sheet of paper and then flexing the two loose pieces like legs. You will more easily tear at the end of the cut. Now instead punch a round hole in the middle and make the same cut up to the hole. You'll notice it is much harder to rip the paper by moving the ends.
Oohh! That's good example, I may borrow that to use with my students. Thanks :)
The stress relief at the shoulder of a blade is paramount! At BKS we have a gentle radius there on both sides of the blade and the majority of our guards are press fit with a stamp first that accommodates that curve at the junction between blade and hilt. If it's too sharp of an angle quite simply it will fail. Not if, but when. This isn't to say it cannot break if you do it correctly but rather that you're mitigating the probability of it happening. As Matt says no sword is indestructible.
Watching this I was immediately reminded of how I learned this lesson from Matt in a Man at Arms video at some point.
Beat me to it lmao. Hi Rick
@@flatlineforge5119 Hello hello 👋
Love the depth of your expertise, and the work you are doing with the collaborative sword productions you are involved with. I hope one day to be able to order one of the swords you helped making man.
Oh shoot. Sup Metatron 😂
@@ColossalSwordFormAndTechnique Hey there
Great video Matt. Here is another possible approach to avoiding this problem...
The problem is that a crack can form at the stress concentration in the sharp corner where the tang is meeting the blade. As the sword is used the crack will work its way across the region where the tang meets the blade and eventually the tang breaks off. Assuming that no crack has formed yet it is possible to take a drill (preferably using a drillpress and a secure vice) and drill two small holes roughly centered at the points where the tang meets the blade. One would expect removing that material makes the sword weaker however the radius of the drill hole will reduce the stress concentration and thereby avoid the formation of cracks.
If there is already any evidence of a crack between the blade and tang it is best to get another sword. The sword may seem perfectly fine an instant before it snaps. Annealing a blade that has already developed a crack will not prevent the crack from growing through the metal (though in fairness it might slow it down a little...)
Obviously the best solution is to have a good radius at the blade meets the tang.
As someone who wants to become a swordmaker I feel this video was made for me. Thank you for the advice.
The Website from Zornhau have extremely good data sheets from original swords maybe the site is to usefull !
Even with data of the distal taper !
@@killerkraut9179 What website?
I have broken / tested a lot of knifes over 25 years in my job in a knife factory (Brusletto, Norway). Even a smal radius at the tang make a big diffrence. And also the grinding marks is in the lenght of the tang. Sorry ,horrible english.
Your English seems fine to me. We would call the plural of knife "knives" with a v, but who cares, as long as we understand? Also, many English speakers don't do well with written English either. I feel like many people who use English as a secondary language actually use better grammar than native speakers as often as not.
I have learnt to my cost in the past that leaving a very angled tang to ricasso...not a good idea. I now always round the juncture from tang to blade and haven't suffered the old problem of snapped tang occurring. Love the videos and await the next..!
On the other hand it's safer to have it break at the tang than in the forte because there's not much metal to potentially injure partner/opponent ;)
I'll say this (as a relatively competent smith) - it's a bloody sight easier to peen a tang over (assuming you don't have a torch) with mild steel or wrought iron, if you bugger it up after the first heat.
For longer knives and swords, I don't harden tangs and bases of blades (ricassos, if you like) either.
I would be very interested in a video going into the pros and cons (bar stock vs forged) @15:30
100% agree. Id say about 70% of the modern repros that ive had fail on me have been for those very 2 reasons. They snap at the transition, inside the the hilt or the pommel snaps off.
At the sword smithy where I work. we don't quench the tang, when I first started working there I was surprised by it, but no one has complained about our blades breaking since I have been doing it like that. Also makes it a darn sight easier to peen the back end.
These are all very good points. I haven't stepped up to making swords or long blades yet, but I remember one of the first hidden tang knife videos I watched in the old days of early TH-cam was of a smith going step by step through his heat treatment process and after straightening his blade he drew back the temper of his tang by locking the blade in a vise with wet rags around the blade and using a torch to draw the tang back from martensite (hard) phase. It's a nifty trick and I use it for my smaller knives that usually get dunked all the way into the quench. You can even do this to the very spine of a blade to give it a bit more flex if you're really careful and use a low flame, just watching the oxidation colors to creep up on a higher temper. That's very tricky though, I'm not going to lie.
Radii in corners comes under design geometry. The metallurgy is a separate issue. Surface finish and the 'lay' of machining marks are also critical in stressed areas. I chamfer and buff all edges in this area to remove any micro cracks along the edges and reduce or remove any deep scratches running across the blade-tang. Scratches running length-wise are less of an issue.
Remember the de Havilland Comet.
Good point Matt, in a rapier competition my blade snapped at the tang, which had square shoulders while parrying a cut. I was hit by my own blade and then the opponent's, a double hit and I got all of it.
Being a knife (and occasional sword) maker, I do all those things, and they were taught to me when I was learning the basics. It varies as to whether I quench the whole piece or not but I will always use a torch to anneal the tang, in the case of knives, so I can drill a hole for the pin(s). Good call though, bringing attention to this stuff is important.
Annealing the tang sounds like a good idea.
Sam From Castille Armory chiming in, and thank you Matt! This is all absolutely legitimate information and realistically it doesn't matter if you have a large industrial setup like we do or you are a one-off sort of boutique shop. If you are making swords for any kind of use with exception pretty non-functional wall hangers, the tang needs to be able to stand up to abuse and shock. As Matt mentioned to start, putting ANY kind of radius in the tang/blade shoulder junction is a good idea. Realistically the more radius you can add, the better. We try to standardize something at least a 2.7mm radius (0.10") wherever possible. I do want to note that the lighter the blade, say modern epee blades, the less it really matters as the stress and shock that a blade like that is going to see is far removed from say a heavier arming sword blade. It's still a good idea, you would be surprised what a tiny radius will accomplish in the heaviest Buhurt blades. Now, mass manufacture blades of mono steel in the modern fashion, 5160, 6150, 9260, 80crv2, 1075 and 1095. We harden the raw bar first then use waterjet technology to cut the blade blanks from the bar. These hardened blanks are then ground to the diamond distal cross sections that give them flex and weight distribution as desired. It is an easy way to mass produce blades and not have to deal with a lot of blade straightening; the heat treat process usually will incur some degree of warpage especially edgewise "sabreing" if the blade is pre-ground. This means that the tangs of these (our) blades are full hard and therefore have not only the issue of being brittle, unmovable and having little shock absorbtion as Matt explained, but an additional issue that Matt didn't cover. An issue that plagues modern manufactured fencing blades- Thread! Threaded tangs have been standardized among modern blade makers along side peened tangs. Threaded tangs are nothing new as Matt demonstrated with the antique blades he presented in this video which were threaded. They offer modularity first and foremost so switching out hardware is easy, say if the blade breaks or if a practitioner wants multiple blade options for a specific set of hardware. The issue with full hard tangs is that threads can't be cut on them, the steel is nearly as hard as the cutting dies. There are two ways that manufacturers deal with this. The first is welding thread to the tang. This method is fairly common. While it is quick and easy, if done without further processes, welding high carbon steel is wrought with issues. Microfractures are the biggest side effect of welding high carbon steel. Essentially when welding carbon steel, you're hyper heating and hyper cooling a small area. The surrounding boundaries of the weld draw the heat down quickly after being heated to temperatures over 870 C (1600 F). The thread stock, a different alloy- often low carbon steel, expands and contracts at different rates than the tang steel during this process. This uneven expansion and shrinkage results in tiny fractures within the weld junction. At this point the High carbon side of the weld is very hard and brittle and will break quite easily so there needs to be a annealing process to soften the weld area. Once this is done, the welded area will be much stronger and will bend rather than break BUT those micro fractures are still present. Preheating the weld junction before welding can greatly reduce the occurrence of these tiny fractures. If you're a long time practitioner, you've probably experienced broken thread right at the tang, thread junction. The other method for dealing with threaded tangs, which we now use and have for nearly a decade, is to anneal the entire tang region using an induction forge and cooling the tang slowly in vermiculite. This process, usually 3 cycles, draws down the hardness gradually and evenly along the tang and makes the threaded portion more than soft enough to cut threads directly. It also drops the hardness down in the tang/blade shoulder region reducing the risk of breakage in that area. This process results in a very strong tang portion and the strongest thread section that can be afforded.
One of the things I learned in school during blueprint and manufacturing classes was that radius is always prefered even if not needed.
Thank you. I'm neither a sword maker nor a sword buyer but I do find this topic interesting. It's easy for us to deceive ourselves and believe we "know so much more than they did" and end up with cosmetically better but functionally worse products.
A lot of this isn't necessarily a "we know better now" thing. Most makers know how it SHOULD be done, but doing it the right way is usually much more expensive. Manufactures are cutting corners in production processes in order to save money. Forge welding on a low carbon tang is a whole new series of manufacturing steps that will nearly double the production cost. Even just annealing the tang on a mono-steel blade is an additional time consuming process that adds up to serious money over hundreds or thousands of blades. Cost cutting in almost any field results in inferior products. Conversely, most people aren't willing to pay the premium to have things made properly.
I'm a mechanical and aerospace engineer:). As for the tangs. I believe the soft iron is used in the tang to make it easier to mount hilts. And no matter how it's heat treated, there is no chance that tang will harden. If they knew the heat treat process was more controlled and guaranteed no hardening of the tang, they would have kept it one piece. Unhardened is just as tough and bendable, if not more so, than iron, the only real difference is the chance of it being hardened. Deltin blades are 6150 steel, same as what I use. It has a very large amount of bending before snapping if it's properly heat treated. I always soften the majority of the tang, but it does depend on blade geometry. The problem with a lot of tangs in modern swords is the stock is too thin for a soften tang.
Great Video!! Thank you! I learned quite a bit from your explanation of sword construction and how it influences durability.
If you look at a hardness vs toughness vs tempering temperature chart for steels, they often have a toughness peak somewhere in the middle of the tempering range. That should be the target temper for the tang, not full hard or full annealed.
Just a quick point; you _can_ harden low-carbon steel, but not brilliantly. It isn't purely done through heat treatment either. You need to use high concentrations of cyanide-containing substances in which to 'quench' them. My father used to do this with low-carbon files for woodwork (not metalwork) and he absolutely swore by the process. In those days it was also much easier to get hold of the cyanide--he would even use the dirty liquor afterward to kill dandelions around the garden! I seem to recall him telling me it was only 'case-hardening' though, which means the hardness does not go all the way through the chunk of metal but just forms a 'crust' on the outside. This gives very specific performance characteristic which my dad was after. Likely for combat use though it would be far from ideal.
As an aside--the sword-making process depicted in great detail at the beginning of both the film of 'Conan the Barbarian' and especially the novelisation would have resulted in a form of case-hardening as well--only a thin layer of cast-iron would have been converted into (low carbon) steel. The 'Father Sword' that was made in this way broke against high-technology Atlantean steel, which assuming the Atlanteans knew as much about how to make steel (or more?) than we do would have almost certainly happened in real life as well.
The big difference in modern steels was the introduction first of the Huntsman Process and latterly the 'Bessemer Egg' convertor--these were then followed by 'cupola' designs and eventually 'reverberatory' technology and beyond. The steel that a modern foundry in Sheffield (if you can find one still in business!) or any other steel-making centre can churn out today is the very best quality that has ever been produced in human history. All the myth-making and fantasy guff about pattern-welded 'Damascus', 'Wootz' or Japanese sand-steel is nonsense. We can make it quicker, better and in hundreds of ton quantities, no fetishistic folding or prayers to the Buddha required!
*EDIT:* In regards the differential hardening approach I wonder if you could apply the Japanese technique and cover the tang with clay so it cools more slowly than the blade resulting the same hard blade, soft tang but done in one step?
It would be interesting to test if tangs made out of iron and welded on, or made out of not hardened steel, really help with reducing the hand shock, all other things being equal.
Try a Natchez or Laredo Bowie from Cold Steel . It's a cable tang.
excellent vid! i apply these concepts to the swords and knives i make right now. however it would have been better to zoom in with a contrasting background. i knew exactly what you meant but couldn’t see any of the details you picked out very well at all.
Thanks for the video, Matt, it is indeed an overlooked but important detail. One of my clubmates broke a sword from a popular HEMA manufacturer at the tang/edge transition point just by swinging it hard with poor edge alignment.
Great tips. Thank you for publicizing this.
As a machinist of some years, the lack of a fillet ( the correct term for a radius or rounded _inside_ corner) was the first thing I noticed on that blade. I knew that would be the first thing you mentioned.
As a bladesmith all i can say is you can have exactly what you want as long as you can pay for it but if you expected to get everything for $1000 you are dreaming. Something simple like a radiused tang adds hours to getting a very tight fit to the guard. It isn't that bladesmiths are ignorant of the best way to build something. Bladesmiths have to build to a price people are willing to pay and that leads to compromises.
Following your instructions I just told all the swordsmiths I know about this. It took no time at all.
Not a maker, but I still found this interesting.
Love videos like this, more please! Was looking in to investing in another sword recently. Was surprised by the difference in ricasso thickness between suppliers, kvetun came out the best in this regard...
I'm happy to see this comment having just paid for my first kvetun sword this week.
I recently bought some used farm implements and the previous user modified some 3/4 inch plates and added a 90-degree notch to accommodate aftermarket hydraulic rams, needless to say, 2 acres in, the tab snapped right at the 90-degree notch. just wanted to say, the information is applicable beyond swords lol.
I had a 1860 saber break when I was going through cutting fruit while mounted. It was a replica, but still when we took it apart the tang was just tiny compared to the originals.
As a civilian, I have to say this was fascinating Matt! ❤
I've taken a small round file to some of my swords tang shoulders after learning this. I have been fairly rough on many of my swords but only broken one before. It was not a good sword any way. But with some of my good swords I've cut pine tree saplings, hard bamboo, 1/2 inch plywood, thin pots & pans, etc. Given some of my swords I've had since the mid to late 90s & they still survive...well that's why I consider them good.
Cutting into it is the worst thing to do...
@@vyor8837 Not cutting, filing. And it's only bad if you do it incorrectly. The file I use is about half as thick as a pencil. Slight rounding the angle, then leveling of the shoulders & tang to match removes minimal material & eliminates the right angle that is certainly a weak point.
The key is to remove as little metal as possible. And last sword I did only required removing less than 1/2 millimeter of material. It's also best if the tang is pretty substantial at the shoulders.
That is probably the most informative Sword Making video I think I've ever seen! I enjoyed it immensely!! Thank you!
I very often use mild in a tang with an interlocking forge-weld. I've been given crap about this, but I still continue, and I never harden the tang even where I don't.
This is the top and very specific content you never fail to deliver. Thank you !
Mechanical engineer by training here, just checking in to say that Matt has an excellent practical grasp of how metal behaves under stress. That was a very good explanation of stress risers and how softer metals in critical areas can prevent breakage. Brittle metal is bad.
You can find the charts for the differences of the shoulders and radius under mechanics of solids.
Hardening the tang makes it harder to thread, drill through, or peening if doing after hardening. Tempering does decrease the hardness but it will still be fairly hard. Annealing/ normalizing like what he mentioned would make it easier to do post processing. And make it softer and allow it to bend not break like he mentioned as well.
Very good video and interesting look at historical and modern sword making
What you said about the tang material makes practical sense. A sword that breaks midway up the blade it's still usable. If it breaks at the guard is only good for throwing at someone.
Not quenching all the way past the ricasso can cause an issue from a looks perspective where the metal won't polish the same in the hardened/unhardened regions. Pattern-welded steels will show this clear as day after etching.
I agree though, if you buy a sword you're going to beat up, no harm in taking it apart and heating the joint out to a pale blue temper to soften that region. Bonus is it will make filing in some radius there easier.
I solder the cross guard to the tang. This results in the tang tearing rather than snapping, and when fighting with them you can feel the tang tear and stop before your blade flies into the audience....
You left out one of my pet peeves, welding a piece of threaded rod on the end of the tang.
If done properly it’s at least as good as simply threading the end of the (unhardened) tang but I’ve seen welds that look like saltwater “corrosion welding” and fail easily, and the threaded rod commonly used seems prone to stretching and consequent stripping of the threads.
Otherwise I take a little pride in accurately predicting your actual points. See? Some of us do pay attention. 😃
It's interesting that iron / mild steel tangs were welded on because many years ago I made some Anglo Saxon pattern welded blades and I forge welded on a mild steel tang to get a little more strength in the tang. Good video, I learned quite a bit from it. Thank you.
I don't make swords. I don't own a sword. I do play tabletop RPGs.
This was a very well done video on the subject. To the point and easy to understand even for complete newbies like me.
I certainly liked and subscribed. After I leave this comment I'm going to do a dive in on your channel.
Good advice, when I make a sword I follow these very important principles. I would definitely not harden the tang or try to weld it. I have seen that go badly.
I'm just starting blacksmithing, and was thinking about this exact thing - the sharpness of the radius of the shoulder. Thank you for validating my thoughts on this!
The soft tang and ricasso thickness was a new one for me though. 🙂👍
In the past it would've been easier to find someone relatively local to do minor repairs like a bent tan or w/e for a reasonable price so that's one thing to consider.
Having something that won't need any repair work done unless it's a major event might be preferably for a layman.
So one of the few things I was taught to do correctly making STAGE swords was the cutting off of the thin tang and welding a nice thick mild steel one back in?
The boss had learned to make them that way because of how upset stage managers got when a sword broke and the managers had not rented an extra as a back up.
The transition between blade and tang, yep, that is the point of failure that I have experienced as well. Sparing with a mate, my whole blade went flying, that was the exact breaking point. A third mate was missed by the flying blade by about a foot.
I've always seen blades break at the tang, and indeed that always seemed like a fragile region to me. I've made a few crossbow steel bows, and when everything flexes, it stays together. If you stress only one part tho, or make it with a weak point, all the tension is going to flex this point instead and it's gonna shatter on you. So for my knives and swords, i usually only quench the blade, and the tang never even touches the water. Also beacause i only use a charcoal forge, i can avoid heating up the tang part altogether, so even if it gets quenched, it doesnt actually hardens. I don't think i've ever seen my blades break at the tang, but the heavy distal taper makes the blade bend instead of the tang part, so that helps too.
Great video, Mat, as always !
As an engineer but not a sword maker, I would be inclined to make the thickness taper rapidly near the tang and then make the tang a uniform thickness. The reason is to increase strength just where the leverage is the highest .
that was a great video I've always wanted to see what the tang looked like on a 1796esk blade. I wonder if you would be I interested in doing a video on ww2 British and American machete typology.
I notice the legitimatus Collins and co machete seem to differ from the onterio machete.
certain variants of Collins have a slight upward curve which for me looks really nice. the onterio machete is very workman like and I belive still supplies the US military today.
(and that's the full extent of my knowledge lol ) then you have the British machete aswell.
many thanks Mark kiely
Yes! Yes! Yes! Corners create stress risers.
For amateur builders, drill (slowly, to avoid excess heat) before bringing out the angle grinder or saw.
THANK YOU!
Every sword making video I watch has this mistake.
They also usually make the tang way too narrow/weak.
Huge mistake unless it's only for display. In which case, I wouldn't own it.
Another (not particularly useful) perk of mild steel tangs is the resistance to rust, since the higher carbon content the easier it rusts. I can see this being a useful perk in tropical colonies where moisture gets everywhere, while cleaning rag - not necessarily
As you probably know due to your background the difference between high carbon and iron preservation in the same medium is visible with a naked eye, and the oxidation slows down with time in case hardened objects, as opposed to what we're used to in our car frames
If increasing bar stock thickness is cost prohibitive, increasing the profile width of the tang will at least give you the same cross sectional area.
Though the second moment of area (a property relating to resisting binding in a given axis) won't be identical.
This is very interesting! I never imagined that they would change the type of material from the blade to the tang.
The 10mm-thick ricasso is also interesting in terms of puting the PoB close to the guard.
What you said in this video about tangs and the rat tang that connects to a wider blade is also one of my problems with sword makers
Also when the tang connects to the blade and that portion breaks
It's often times called shearing
Shearing metal is something to know
As it is the definition of what happens
Heat treating the tang is purely a modern thing, in all the older books I've read about making blades and swords they only heat treated the blade, typically as you described. Definitely not even all the way to the tang. True in knifes as well. As for the welding different materials it is undoubtedly more difficult to do, and most modern craftsmen don't think in terms of forge welding either, so they'd most likely do a butt weld as opposed to a cleft weld hammered shut. I think the butt weld would undoubtedly be a weak point in a way the lapped or cleft weld isn't. I think as long as they avoid heat treating the tang this wouldn't be much of an issue though.
It would be extremely difficult to butt weld a sword tang onto the sword, unless you did it at a stage where the material was still in a thicker billet form. I'd be really surprised to see it done. The Viking Era swords I've seen (from books) have a lap weld maybe an inch or two before where the tang itself starts. I really think that forgewelding used to be thought of the same way as we think of tying our shoes. Which is to say not very often. Not because it was difficult, but because it was such a simple and routine part of making just about any common item. I like your comment about how modern craftsmen don't think about it in the same way.
Paused at 9:26The tang has a Soft wrought/iron handle. I don't forge weld handles, but I do soften up them. If you know what you're looking at, you can see the line of the weld. You can harden mild steel to a degree, but it's not going to have as much martinsite as Higher carbon.
Knew what you were going to say before you said it! Same thing applies to axles - people have been killed by sharp internal shoulders propagating cracks leading to shear fractures. 👍🏻
Great video, though you didn't mention what I have found to be the even worse flaw in modern blades, especially very cheap ones (but not always).
Sword makes really should not make a tang by mig welding a thin bit of threaded rod to the end of the blade or partial tang. I have seen it most often where the forged tang is only about an inch long, and you then have a m4-m6 length of threaded rod welded (badly and presumably not tempered afterwards) on to make up the extra length and make fitting a pommel easy.
It doesn't take much at all to make that weld snap, and then the whole blade goes flying off, leaving the hilt to fall apart in the wielder's hand.
I have mostly found this in very cheap swords that are only really meant for display, but I own two swords sold by different companies that were sold as reenactment fencing blades that have done this too.
Awesome video, as always. I'm hoping to start making blades (knives and swords, purely as a hobby), and this is really interesting to me!
However, with all your videos I've watched, I never noticed the aquarium on your cabinet. What do you have in there? A snake?
Good analysis, thank you. So, one reason a maker might desire a hardened and tempered tang/ricasso junction rather than annealed, is that a bent junction is not very useful. What are you going to do with a significantly deformed sword? Bend it back and it will have become much less tough. Properly heat treated steel of appropriate composition is astonishingly difficult to break (in appropriate dimensions) at the junction. Civilization rides on heat treated steel springs, and while they do occasionally break, mostly they work as engineered. Consider the very thin edge impacting armour and bone at velocities perhaps 150 fps versus the handheld, beefy tang junction which is much slower, and somewhat supported by the handle, and I think the real issue is the edge/s and the tip mass in overstrikes, or main mass in hard tip strikes.
I would certainly like to see evidence of sword failure at the junction when the steel is properly heat treated and appropriately proportioned and no flaws (slag inclusions for example) present... it would be fascinating.
Love the video... you did describe the Alexandria sword as being four and a half centimetres thick... (17:01) mind-boggling ;)
Interesting topic and well done. I wonder if the tang's thickness could have been a way to balance some of those older blades. Great explanation of why and why not to do it.
I know on the saber I have, it is the actual thickness of the blade spine all the way through to the pommel where the guard attaches. I've been told it is a civil war Ames blade made in Japan, but I can't tell because my father covered the entire thing in orange shellac after getting it from the mud near the James River in VA of the USA. The wire wrapping on the wood is gone except for a small piece and no scabbard was found. I've never found an example like it. I was told by someone else it was not from the civil war at all, just stamped when the owner entered the war.
Take Care and Stay Safe.
I appreciate the "consumer" clarification. I was having trouble deciding what wine pairs with a grosses messer anyway...
Amen - great tips.
Another interesting upload.....they really did make weapons work as weapons back in the days of swordplay that your life depended on.
Before you grind or cut your tang shape from bar stock, you can theoretically "upset" the metal in that area to thicken the metal at that junction.
Better still, forge your tang rather than use a metal removing method and it'll be problem solved.
I'm a tool smith and sometimes that means I make knives and swords. I always start with a hay rake that's about a hundred years old. When the blade is done I forge weld a wrought iron tang and she's got the rounded bit instead of a right angle. That's how I've always done it.
Also what you described is not anealing, its normalizing. To aneal you bring the work piece up to a critical heat( non magnetic) and then you bury the piece in wood ash. That allows the piece to cool very slowly and makes it dead soft. With normalizing, you bring the piece to a critical heat and allow it to cool in a spot in the shop that doesn't have a breeze so that it doesn't air cool. Its not dead soft but its not hard either. One will do this several times to get the grain size smaller and tighter before you do the heat treatment.
If you are making a sword out of all high carbon steel than you are right. Don't quench the last couple of inches above the tang. You already normalized the entire piece several times so just put it out of the way and let the tang cool. If you want an anealed tang then bring the entire piece to critical heat, quench the blade except for the last couple of inches and then quickly bury the tang end in wood ash.
Depending on the use of the sword I would do either. However like I said, I prefer to forge weld a wrought iron tang. My tools and blades come with a life time guarantee barring stupidity. And since I'm not fond of making swords, I do it right the first time. Iron tang that has a radius where the tang meets the blade. What we call the weak part when the tang is at right angles is a cold shut. There are several things called a cold shut and stress riser works too in this particular situation.
Thanx for bringing this important point to those that don't know better. OZZ- owner of Kalapooia forge.
Totally agree! I always steel leave tangs soft, with radii, and thicker, although admittedly I've never forge-welded in a separate mild steel or iron tang. For my bronze blades this isn't an issue as they are cast full tanged and flanged :-)
As a sword and knife smith I'd add one other thing (sorry if I dont use right english words - not a native speaker) - if you have the thick junction part, do a distal taper on tang. If you leave it 8 - 10mm thick all the way, its weaker than when it goes down to something reasonable like 4-5 mm. Its about vibration - if you hold it by the jucntion and hit it with something, blade must sound one nice tone and tang other, higher. If its just a lump of metal, the vibration from blade will stop mostly at the junction where it will build up stress fractures. The handle and the pommel will act as a nice dampener cushion, but the blade-tang geometry must let them do that.
FINALLY SOMEONE ADDRESS THIS!! The Companies of Lower End Swords Always Make Handle and Tangs Terrible.. . You only One That Has Called this out FINALLY!! I been asking reviewers to Look at Tang & Handle..Ive watched all the Sword Channel Guys. Your the Only Guy That Has Finally Done This!!
This is the main reason I tend to Cutler together my own swords from a bare blade: I've then seen how the shoulder looks, that it has a proper radius and is't sharp. Also then I can see that the tang is wide and also not tempered hard but soft enough to peen.
The next thing is the screw end. I understand for interchangeability from sharp to blunt on your favorite rapier handle you'd want this.
For target cutting though I would advise against a tang that is held in with a nut (if the screw end of the tang is tempered). Because that too is a weak point. If you use a blade like that attach it further with glue.
I build a few swords and I never had a sharp angle because I always used a full Tang never such an angled and pointed Tang to put a hilt on . I always wanted as much support under it as possible.
Cable tang on the Natchez and Laredo Bowie's from Cold Steel are a modern way of doing the softer tang material , basically the handle will die long before weld and cable tang will snap off.
I think a lot of people can learn to be cautious with the "tang".
I've learned that in my life.
Another great vid, somehow after years I wasn’t subscribed?!
Great info, very clever insights. When you said you’d been playing with swords for 20/30 years I started trying to figure out your age, and I honestly can’t. Are you the count of monte christo?
Hi! Professional cutler here, I have to say I agree completely with these points, and have a few more myself.
Shock transfer is a huge issue if you are going to be using any cutting tool, for any lengrh time, in a task that involves impact. Having a proper geat treat process, good transitions, properly radiused transitions and a soft tang all make a huge dofference to hand shock. Its true in swords and especially axes. That single, homogenous, hardened and tempered piece of steel is going to transfer shock directly into the hand of the user and cause soft tissue damage, as well as, potentially, snap the tang off at the guard or inside the hilt.
A point you tou hed on very briefly, but I think warrents a little additional attention, is the welding together of dofferent metals in the tang. I am very much of the opinion that there are only two ways of doing this, a right way and a very wrong way. Scarf welding, or any of its variations, gives a lot more surface area of the two metals a place to touch, allowing for that transfer of shock to occur over a larger area. In turn, this should minimize stress put on any spots where the weld isn’t perfect and also, dispers that shock a little more beforw it transfers to the hand. Butted welds on the other hand, tend to involve very minimal amounts of surface space touching and frequently also involve very dramatic changes in material size. In my experience, this tends to multiply felt shock a great deal ans concentrate that stress directly at the weld, which seems to almost always lead to faulure of the tang.
17:02 That Alexandrian blade must have a monster thick tang. 4.5 Cm.. Wow.. I know it is a slipup. But a bit fun to imagine a blade with 4.5 cm thick tang
I'm sure there was some understanding that a bigger radius on the join was stronger in history, but it wasn't really until the 20th C that the idea of stress risers really became known. It's especially clear what's going on with visualization tools like piezoelectrics. If you have a blade you want to add some radius too to add strength, a non-intuitive way to add strength is to cut the (partial) circle into the corner. probably in the direction of the blade, seeing you likely don't want the tang to get thinner. Contrary to expectations, this reduction of stress risers more than compensates for the lost material. It's a pretty common technique when you'd like to match up parts as well, where a concave rounded corner would get in the way.
I wonder. Would there be any practical issues to making the blade taper into the tang very gently, so that there would not be a clear, distinct shoulder at all? Granted, it would mean that you'd have to have a portion of the too-wide tang exposed since it would not fit into the hilt construction, but blades with ricassos are an entirely normal thing.
(I'm actually wondering if there is any reason that this would weaken the blade construction. Ostensibly, the thinner portion of the blade will be exposed to any and all of the same stress anyway, whether it is exposed or a shoudler, and it would be very unlikely that someone could cut through the somewhat narrower base, or otherwise notably damage it any easier than just snapping a structurally weak blade in the first place.)
Having a shoulder makes handles and especially guards much easier to fit and assemble. And you also don't need that much material in the handle, the only job it's doing is holding the handle to the blade, and as long as it does that securely that's enough. If you look at katana tangs they are very similar to what you describe but they still have a shoulder because it's very useful.
@@UnbeltedSundew Yes, I wondered about that. It's certainly true that no shoulder at all would make it harder to get a tight fit for the hilt assembly.
Thanx, watching forged in fire, and you have answered most of my unasked questions
About the Indian cavalry blade: the angle is actually very obtuse. As this is a single edged sword, it's the angle on the same side as the spine that matters. The one on the side of the edge is straight, but this is simply to allow the tang to be broader than it would otherwise be with obtuse angles on both sides.
I haven't watched for a long time and honestly thought you would be a sword & knife maker by now Lad.
Great points, Matt.
I'm sure that a softer steel would also dampen vibrations more as well as soaking up a little impact energy.
really good video and i am glad i figured the angular part of the tang on my own from the experience, but i have a very important question. I am currently putting together a sabre and what i would like to know is the construction of the hilts, baskets and the different types of these hilts and how are they put together. Another thing i would like to know is the best way to secure the entire handle. Should that be done with riveting the end and securing it till the end of times or should i go with the thread as shown with the blade at 7:25.
For some reason i always think of riveting as the only right way and threads to be "modern and not so classic" but after seeing this antique blade with the thread on it, i am not sure anymore.
PS. When it comes to sabres i was always interested in the entire construction of the entie handles and how it was made and since you are very familiar with sabres i hope you could help me.
Anyway amazing video and thank you :)
6:50 there is another option of giving more strength to this part you are talking about. Don’t cut the angels out on the same level. That gives you a bigger cross section without the use of more material. And if u normalize the „cuts“ in relation to the more ore lesss „diagonal“…. Sorry I am no native speaker, but the trick is the same with tank armour, just angle it. Make a small drawin and you will see, … add some vectors for the possible forces …
One of the earliest passenger jets had square windows, the stress fractures at these points are why all passenger jets now have rounded windows.
I got a totally awful wall-hanger from Corrado Cutlery in Chicago a whole bunch of years ago. It's that tiny little tang, with the threaded rod welded on for the pommel knob. The damn thing was only good for hanging on a wall, because the tang could not take the shock of hitting anything with more than a fly-swatting force. I think that corner is angled instead of properly radiused.
The rounded corner thing is something that we've talked about when learning to work with sheet metal.
I haven't made any swords but I've noticed that as well if it is cut in flat instead of cut in and then filed in it'll cause more stress needs to be slightly angled up from the blade