That was a dam good idea! Good job in even conceiving this experiment. I just started forging recently and rebar is what I use, for one thing it's abundant, but more importantly guys think its the coolest thing. I think a lot has to do with the fact that a lot of guys work with or around rebar as far as the construction industry goes, when they see one of my rebar knives ( they are actually daggers ) they get this grin (makes it all worth while ) and immediately the " can you make me one! " follows. I can't make enough of them, my primitive set up has a lot to do with it. As soon as it's done it leaves, I don't even have one for myself. And I sell them without putting an edge because they ain't going to use it. It's a novelty not a utility. How much do I get, it various. I'll say it averages out to 20 to 30 dollars.
Cool testing!!! I made one from a piece of old rebar I found while walking some RR tracks years ago. I quenched it in vegetable oil. It hardened nicely and I tempered in the oven to complete the whole heat treating process. It retains its edge very well. Of course, today's rebar is much different than it was 50 or 60 years ago, but it looks pretty cool and works just fine. Enjoyed the video!
This is the reason tongs forged from rebar maybe dangerous due to hardening while working and cooling in bucket. They can unexpectadly cracks with hot metal in it!
Seriously, I wanted to do this ever since I was a kid... why didn't I start sooner? Turns out it's pretty easy to get started, especially with MILLIONS of TH-cam videos showing you how. Have you checked out ZNA Productions' channel?
Do it. Its so easy to set up and you really don't need fancy equipment. Get a broken semi truck/trailer axle and use the cross section for an anvil. Use a blow dryer and some cast piping for a funnel. Lay some clay bricks for a fire pot and use a rock as a hammer :) P.S. if you use a blow dryer, its really simple to convert them from AC to DC. Take it apart and remove the 4 diodes and heating filament. Run it at 12V 4A straight into the motor without any resistors, and you will have much more static pressure from the fan. Remember a good forge is all about its air supply. You want a high volume of air at high pressure, but you don't want the air to be moving quickly, that's how you burn your steel and use up all your coal.
Quenching a low carbon steel in oil will cause the steel to slip into the ferrite head of the TTT diagram, basically instead of directly hardening the steel, it martempers it before it gets hardened.
@@shadowninjarider374 So I think the best thing to do if you truly want to understand it is look at phase diagrams for specific steels, each will have its own diagram plotting temperature on the left and time on the bottom. These diagrams will give you a good idea of what your steel IS actually turning into rather than just assuming its harder. I'll give you a quick summation tho. Austinite is carbon steel that isn't hardened, martensite is hardened, ferrite is a phase where crystals can reshape. If your steel is low in carbon and you dont quench it quick enough (in water instead of oil) you will actually make ferrite carbides so to speak before you start making hard martensite, which is bad if you don't control it for a specific outcome. To check this, buy a cheapo hand file and temper it yourself. Just a light temper so the file loses some hardness but not all. Then you can use this as a makeshift hardness tester. If the tempered file cuts the material deeply then its already martempered (it became ferrite before it became martensite) Rule of thumb (for me atleast) is to quench with oil first then move onto more extreme mediums, but if I know the steel is below 0.3% carbon or insanely high alloy content then I wont even attempt using oil. I hope this helps :)
Easy rockwell test. make a spring loaded punch, use a piece of martensitic leaf spring material as a reference (80-90r). Rockwell is a measure of plastic resistance, not hardness. So a high number will mean the punch doesn't drive very deep, and this is linear. So if your spring loaded punch made a 0.1mm wide mark on the leaf spring which is at 80r then a 0.2mm mark will mean you have something close to 40r. If you want to test hardness. Simplest method is to drop a ball bearing onto the material. Once again, use a leaf spring as a reverence. The lower the bounce, the more energy was lost due to elasticity. This isn't linear though, but you can get a good idea.
@@awashburn6944 I tried to keep it simple man, you're absolutely correct. But hardness in laymans terms is the lack of ductility+high yield strength combo, instead of its actual definition which is just resistance to (enter specified force), hence why we have different scales. I studied as a geologist so hardness for me relates to scratch resistance (Moh's scale, also used in machining). But I never use rockwell anyway. File test is really all you need.
Cool. I'm actually working on that video right now. Spoiler alert: The hardened blade holds an edge better than the annealed blade. Lol. You probably guessed that.
It doesn't really matter what oil you use. It's more important to have your oil preheated. Basically, cool oil will be too cool to effectively quench the material because the steel will form a vapor layer around itself and won't properly quench. You want the difference in temperature between the oil and metal you wish to quench to be around 600 degrees C. What temperature you quench at/in will determine hardness, but you always want that delta to stay the same (that is for carbon steel). What medium you use to quench in depends on the metal used though. If you are using heavy alloy metals, quenching in water is relatively safe if you don't stir it irregularly. But, high carbon will almost certainly shatter in water. Light oils are good overall, sunflower/canola/palm oils all work great.
Oh man, one thing you do NOT want to do is have all your power tools laying out, getting showered in sparks from your grinder. You are just filling your electric motor up with metal dust which is going to stick to the magnets and get inside your motors and cause them to run hot and eventually give out, if not short circuit them outright.
Yes, rebar can be hardened in water or brine, but only if rebar is certified. Due to modern rebar often made with no complience to standarts, in some cases it cannot be hardened. P.S. some rebar pieces after polishing and etching can get wootz pattern due to scrap steel they made of.
Thank you for your video. It's amazing to know that low carbon steel can be hardened. It gives me a relief that I will spend less money for practicing blacksmith work. Rebar costs about $0.18/pound at a local scrap yard around here, as compared to $15 -20 for tool steel barstocks (which is to be imported from abroad).
I've found quenching rebar in ice water locks in the carbon better. But since rebar can be a mystery with what is actually in there, your mileage may vary.
The best thing for rebar is usally oil. But for mild 45° steel which is VERY common. I use water and its just about perfect not super brittle but doesnt bend easily by any means (until you put length to it. The longer it is the easier it bends)
What do you mean when you say "eneal" (sp?) ? That was the most flexible piece, correct? So with that method the metal was never quenched, just super heated and slow cooled over a hot forge?
I keep getting little hammer dings in mine instead of flat. Any advice? I'm sure it smooths out with practice but I'm sorta 50/50 on how my stuff turns out. Just started a few months ago though.
A couple of advises: don't remove angle grinder guards. It is a very stupid mistake. Those discs, when disintegrated, turn into light speed shrapnels that can create nasty wounds, if not kill. And wear proper work clothes and footwear. If you love your extremities that is.
If I was gonna forge with rebar, I would use 1 long piece, fold sections of it in on itself, and use the leftover bit as a handle. And boom. Instant billet on a stick. LOL
I would like to find, a resource that can talk about the carbon content. I bet it is easier to find in the large grades, that are used for serious projects like oil rigs, some grades may be almost 3" in dia
some asians knife maker only harden the edge of the knife and not the whole knife in water. maybe this step will only makes the edge keeps its sharpness but not making the whole knife breakable/snap when on heavy load. maybe you could find out as you have the tools and finding ways to make your knife making journey more enjoyable and adaptable to your knives.
testing files are cheap. also if you live in a rural area ask a farmer if you can have a poke around in their scrap pile and try out some different steels then get a book/pdf on basic metallurgy the science is strange and beutiful
in the lower carbon rebar quenchvit with higher color of the fire yelowish white to reach its harder strength ofa blade theres difrent color of fire depend on the carbon content of a metal lower carbon higher the color of a fire higher crbon lower the fire color
Renee Mills you don’t call heating up and smashing a piece of steel on an anvil blacksmithing? Just because he uses a coal forge and grinder, dosent mean he’s not a blacksmith!!
blacksmithing in sandals, what a man!
Fantastic video. Exactly the info I was looking for.
Cheers fella from aus .ain't so scared to have a crack after listening to your mellow voice cheers again .off to av a go thx
That was a dam good idea! Good job in even conceiving this experiment. I just started forging recently and rebar is what I use, for one thing it's abundant, but more importantly guys think its the coolest thing. I think a lot has to do with the fact that a lot of guys work with or around rebar as far as the construction industry goes, when they see one of my rebar knives ( they are actually daggers ) they get this grin (makes it all worth while ) and immediately the " can you make me one! " follows. I can't make enough of them, my primitive set up has a lot to do with it. As soon as it's done it leaves, I don't even have one for myself. And I sell them without putting an edge because they ain't going to use it. It's a novelty not a utility. How much do I get, it various. I'll say it averages out to 20 to 30 dollars.
Cool testing!!! I made one from a piece of old rebar I found while walking some RR tracks years ago. I quenched it in vegetable oil. It hardened nicely and I tempered in the oven to complete the whole heat treating process. It retains its edge very well. Of course, today's rebar is much different than it was 50 or 60 years ago, but it looks pretty cool and works just fine. Enjoyed the video!
I love how all your tools are rebar! Looks ace!
SCIENCE! Really good thorough test, enjoyed your vid thanks.
This is the reason tongs forged from rebar maybe dangerous due to hardening while working and cooling in bucket. They can unexpectadly cracks with hot metal in it!
I liked watching this. Thanks for sharing.
ABSOLUTELY. !!! SEE IF IT'S POSSIBLE TO FORGE WELD THEM TOGETHER AND TO INCREASE THE MASS.
Sadly my forge doesn't get quite hot enough for forge-welding. I'm working on that.
Dude you got me wanting to start a forge myself
Seriously, I wanted to do this ever since I was a kid... why didn't I start sooner? Turns out it's pretty easy to get started, especially with MILLIONS of TH-cam videos showing you how. Have you checked out ZNA Productions' channel?
Grab yourself some charcoal, a hair dryer, a nice rock and get hammering!
Eric Kelly Preach it! If I had known how easy it was I would’ve started this when I was 10 years old.
Do it. Its so easy to set up and you really don't need fancy equipment. Get a broken semi truck/trailer axle and use the cross section for an anvil. Use a blow dryer and some cast piping for a funnel. Lay some clay bricks for a fire pot and use a rock as a hammer :)
P.S. if you use a blow dryer, its really simple to convert them from AC to DC. Take it apart and remove the 4 diodes and heating filament. Run it at 12V 4A straight into the motor without any resistors, and you will have much more static pressure from the fan. Remember a good forge is all about its air supply. You want a high volume of air at high pressure, but you don't want the air to be moving quickly, that's how you burn your steel and use up all your coal.
I've just retired and started making knifes. Talk about a stress remover.I enjoy it so much
Wow, thanks for sharing. I was hoping someone would show the difference between water and oil quenching.
DanielinLaTuna You bet! Glad you enjoyed the video. Cheers!
Quenching a low carbon steel in oil will cause the steel to slip into the ferrite head of the TTT diagram, basically instead of directly hardening the steel, it martempers it before it gets hardened.
@@meusana3681
Yeah....don't know what that means. Can you elaborate please? I'm REALLY new to smithing.
@@shadowninjarider374 So I think the best thing to do if you truly want to understand it is look at phase diagrams for specific steels, each will have its own diagram plotting temperature on the left and time on the bottom. These diagrams will give you a good idea of what your steel IS actually turning into rather than just assuming its harder.
I'll give you a quick summation tho. Austinite is carbon steel that isn't hardened, martensite is hardened, ferrite is a phase where crystals can reshape. If your steel is low in carbon and you dont quench it quick enough (in water instead of oil) you will actually make ferrite carbides so to speak before you start making hard martensite, which is bad if you don't control it for a specific outcome. To check this, buy a cheapo hand file and temper it yourself. Just a light temper so the file loses some hardness but not all. Then you can use this as a makeshift hardness tester. If the tempered file cuts the material deeply then its already martempered (it became ferrite before it became martensite)
Rule of thumb (for me atleast) is to quench with oil first then move onto more extreme mediums, but if I know the steel is below 0.3% carbon or insanely high alloy content then I wont even attempt using oil.
I hope this helps :)
Flip flops are great for blacksmithing! Just got a new like from me!
Easy rockwell test. make a spring loaded punch, use a piece of martensitic leaf spring material as a reference (80-90r). Rockwell is a measure of plastic resistance, not hardness. So a high number will mean the punch doesn't drive very deep, and this is linear. So if your spring loaded punch made a 0.1mm wide mark on the leaf spring which is at 80r then a 0.2mm mark will mean you have something close to 40r.
If you want to test hardness. Simplest method is to drop a ball bearing onto the material. Once again, use a leaf spring as a reverence. The lower the bounce, the more energy was lost due to elasticity. This isn't linear though, but you can get a good idea.
@@awashburn6944 I tried to keep it simple man, you're absolutely correct. But hardness in laymans terms is the lack of ductility+high yield strength combo, instead of its actual definition which is just resistance to (enter specified force), hence why we have different scales. I studied as a geologist so hardness for me relates to scratch resistance (Moh's scale, also used in machining). But I never use rockwell anyway. File test is really all you need.
Cool man and would definitely would like to see other test if you want
Cool. I'm actually working on that video right now. Spoiler alert: The hardened blade holds an edge better than the annealed blade. Lol. You probably guessed that.
FargoFX yeah but still good to see I wanna start forging so I watch all types of videos something I always wanted to do just never did
One question, what kind of oil do you use for quenching ?
Just found your channel in the comments on Christ Centered Iron Works 😃😃 Cool stuff👌
Not only Wood , Thanks! I just found his channel a few weeks ago… Love his stuff. I'll check out your channel too.
We’re going to pretend like we didn’t just see him wear flip flops 😂
What type of oil do you use?
It doesn't really matter what oil you use. It's more important to have your oil preheated. Basically, cool oil will be too cool to effectively quench the material because the steel will form a vapor layer around itself and won't properly quench. You want the difference in temperature between the oil and metal you wish to quench to be around 600 degrees C. What temperature you quench at/in will determine hardness, but you always want that delta to stay the same (that is for carbon steel). What medium you use to quench in depends on the metal used though. If you are using heavy alloy metals, quenching in water is relatively safe if you don't stir it irregularly. But, high carbon will almost certainly shatter in water. Light oils are good overall, sunflower/canola/palm oils all work great.
Oh man, one thing you do NOT want to do is have all your power tools laying out, getting showered in sparks from your grinder. You are just filling your electric motor up with metal dust which is going to stick to the magnets and get inside your motors and cause them to run hot and eventually give out, if not short circuit them outright.
Yes, rebar can be hardened in water or brine, but only if rebar is certified. Due to modern rebar often made with no complience to standarts, in some cases it cannot be hardened. P.S. some rebar pieces after polishing and etching can get wootz pattern due to scrap steel they made of.
Would you please discuss using railroad spikes and old files to make knives?
Bro can i ask ? Any mineral oil allowed to quench
Thank you for your video.
It's amazing to know that low carbon steel can be hardened. It gives me a relief that I will spend less money for practicing blacksmith work. Rebar costs about $0.18/pound at a local scrap yard around here, as compared to $15 -20 for tool steel barstocks (which is to be imported from abroad).
I've found quenching rebar in ice water locks in the carbon better. But since rebar can be a mystery with what is actually in there, your mileage may vary.
Greetings from Arabia!
Can you tell me how you made your Forge
The best thing for rebar is usally oil. But for mild 45° steel which is VERY common. I use water and its just about perfect not super brittle but doesnt bend easily by any means (until you put length to it. The longer it is the easier it bends)
Rebar is actually pretty good stuff. The bigger it is the better too.
Flip flop forging, I love it. I weld in a tang top, no shoes, and basketball shorts. Of course I wear my helmet
Did you cut with your rebar or put.an edge on it at all?
What do you mean when you say "eneal" (sp?) ?
That was the most flexible piece, correct? So with that method the metal was never quenched, just super heated and slow cooled over a hot forge?
Google annealing
Witch oil is this
What kind of oil is that?
I keep getting little hammer dings in mine instead of flat. Any advice? I'm sure it smooths out with practice but I'm sorta 50/50 on how my stuff turns out. Just started a few months ago though.
Rebar has a number somewhere down the entirety of the whole piece. That number like 50 or 60 represents the hardness. The highest i think is 90.
A couple of advises: don't remove angle grinder guards. It is a very stupid mistake. Those discs, when disintegrated, turn into light speed shrapnels that can create nasty wounds, if not kill. And wear proper work clothes and footwear. If you love your extremities that is.
If I was gonna forge with rebar, I would use 1 long piece, fold sections of it in on itself, and use the leftover bit as a handle. And boom. Instant billet on a stick. LOL
lmao 😂
What part of AZ do you live in
Rebar makes great wrench bars and concrete chisels
What do forgers quench their steel into when they say "oil"?
Literally oil.
I would like to find, a resource that can talk about the carbon content. I bet it is easier to find in the large grades, that are used for serious projects like oil rigs, some grades may be almost 3" in dia
I find salt water is good for lower carbon/mild steel
Ian Finrir Yes brine is even faster than plain water or even super quench (brine + soap) is one mean quench.
What kind of oil did you use
U can use canola oil or vegetable oil or mortor oil
Or I believe u can get a specialty oil but IDK I'm just starting but I'm sure about those other oils
I think the oil is better due to the chemical properties it has to reinforce the metal
some asians knife maker only harden the edge of the knife and not the whole knife in water. maybe this step will only makes the edge keeps its sharpness but not making the whole knife breakable/snap when on heavy load. maybe you could find out as you have the tools and finding ways to make your knife making journey more enjoyable and adaptable to your knives.
testing files are cheap. also if you live in a rural area ask a farmer if you can have a poke around in their scrap pile and try out some different steels then get a book/pdf on basic metallurgy the science is strange and beutiful
I am eager to start a workplace for making blades but need some help
No support from parents side ☹️☹️
I have to do it myself.
in the lower carbon rebar quenchvit with higher color of the fire yelowish white to reach its harder strength ofa blade theres difrent color of fire depend on the carbon content of a metal lower carbon higher the color of a fire higher crbon lower the fire color
As a warning to anyone who plans on quenching in motor oil, it turns your knife black!
sooo, water gives you the max hardness, oil is a milder hardness.
Вери гуд, тэнкю .
You are forging in flip flops? Seriously? Is safety not a concern to you?
And you don't forge either, another person who cuts & grinds and only use fire to heat treat?
Renee Mills you don’t call heating up and smashing a piece of steel on an anvil blacksmithing? Just because he uses a coal forge and grinder, dosent mean he’s not a blacksmith!!
Jesus loves you
for the sake of god and freedom . . . please put that wise on a more stable platform . . . it hurt me see it dancing all over the place XD
it hurts me to see "eXX DEEE" anywhere