How to sharpen a unibit, How to sharpen a step bit, specialty drill bit
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- เผยแพร่เมื่อ 20 ส.ค. 2024
- How Tosharpen to step out, how to sharpen a very bet, how to sharpen a variable diameter drillbit All you need is a Dremel tool and be willing to try.
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Thank you, learned something new and saved me a trip. All the while picturing Billy Bob Thorton. Apologies if I’m the first to say that.
Man, I am stoked to find this video. I have an expensive, albeit dull, step bit that lives in my tool belt. I am going to sharpen it tomorrow. Thanks!
How did it turn out leave a comment please
Totally works!! I sharpen bits for work and it's an art that took me a while to perfect. This can be done by anyone with a rotors tool and stones!!
Thank you sir.
I have gotten paid 3 times for a bit I got out the trash.
My $7 Harbor Freight step drill will live to see another day! 😁
......probably just one hole. 😁
I'll buy a good one next time around.
Thanks for that tip 👍
Their cobalt step drills are great and good candidates for sharpening
@@lindboknifeandtool I bought a pair of those not long after I commented here.
.......and it's funny that you just made a comment about those. I used one of them for the very first time, 4 days ago. Yeah, I'm a slacker. 😁
You just reminded me they can be sharpened. Thank you 👍
.......so how do I turn off the Twilight Zone music? 😁
So pleased to watch this video. We as a company go through milwaukee bits like crazy. Now I might be able to save some money! Thank you sir!
Glad to help, they may not be good as new but I hope it saves you money.
This quick lesson will save many of us a considerable amount of money. Thanks!
Considering I was just at homeless deport and the millwakee ones are $85 now... I am so happy I found this video. Thanks my dude!
There's 5 dollars Chinese brands. Yes, they usable but gets dull so much faster.
Wow! Thank you! Saving money 💰 is what it’s all about!
I'm an I'm an electrician commercial industrial. Unibits are they go to hole maker for holes up to one inch. A lot of times the only part that goes bad is the tip, It's either high speed or nothing, They keep going as the tip changes colors and start smoking, We'd figure that the warning signed something is not working right but with enough pressure it will melt its way through.Lol! I've watched some guys go through three or four Trying to drill the holes through a stainless steel countertop, the tip literally gets red hot but they keep trying! Lol! You just gotta laugh. Anyway these are easily sharpened but 99.9% of people don't understand this and will toss those overpriced Klein and Milwaukee bits. I too use a Dremel. I'm a little ridiculous with my hobbies. I'm a big fan of the Dremel I'd buy many many different types of burrs and bits and cutting wheels and disks. The best I found for this specific application is to use either 1 1/4" diamond disk or the same size reinforced cutting disk. I just hold the disk so its flat up against the flute , there's a good amount of flat surface there so its impossible to screw up matching the angle. I use low speed with a diamond disk they work great few seconds per cutting flu is really all it takes. Higher speed with the reinforced cutting desk.
Stainless steel has a lower cutting speed, look up feet per minute, cutting speed for various metals and you will see what I mean. Electricians are supposed to know this since they’re supposed to be the smartest of all trades craftspeople 🙄. For instance, they make a 56 RPM and a 33 RPM rigid pipe threading machine as I recall the RPMs may be off by two or three, but I know if you try to thread stainless steel pipe at high speed you will burn the $400 threading dies right away.
To determine the appropriate RPM for drilling different metals:
1. Consider the material hardness - harder metals require lower RPMs.
2. Check the drill bit size - larger bits need lower RPMs.
3. Use this formula to calculate RPM:
RPM = (Cutting speed x 3.82) / Drill bit diameter
4. Typical cutting speeds for metals:
- Aluminum: 200-300 surface feet per minute (SFM)
- Brass/Bronze: 150-300 SFM
- Cast Iron: 50-100 SFM
- Mild Steel: 80-110 SFM
- Stainless Steel: 30-50 SFM[1][5]
5. Start at a lower RPM and increase gradually if needed.
6. Watch for signs of overheating like discoloration or smoke.
7. Use cutting fluid/lubricant for most metals.
8. Adjust RPM down for deeper holes.
For example, to drill 1/4" mild steel:
RPM = (100 SFM x 3.82) / 0.25" = 1,528 RPM
Remember to balance speed with drill bit life and material quality. Slower speeds generally extend bit life but take longer[5]. Adjust based on your specific needs and material.
Sources
[1] Feeds & Speeds For Drills | Norseman Drill & Tool www.norsemandrill.com/feeds-speeds-drill.php
[2] Drilling metal - speed charts vs reality | The Hobby-Machinist www.hobby-machinist.com/threads/drilling-metal-speed-charts-vs-reality.99330/
[3] Drilling Machines - Cutting Speeds & RPM Calculations - Wisc-Online www.wisc-online.com/LearningContent/mtl8202/MLT8202.htm
[4] Help! Drilling steel,need some help...what rpm should i be at? - Page 2 www.rcgroups.com/forums/showthread.php
[5] Figuring Out Drill Speeds: RPMs and Bit Life www.albanycountyfasteners.com/blog/how-fast-drill-rpm/
Its worth trying to resharpen these. Probably the most expensive drillbit and the easy to sharpen. I even resharpen hole saws.
Do you have a video showing how to sharpen hole saws. Man I need that.
@@rodm5830 The same way you sharpen a hand saw
I use my step drills reliably up to 3/8 in 0.125-0.140 annealed tool steel.
You’ll probably, using a drill press, need to change your speed while going larger
You're the man, thanks so much! Probably not the best idea to use a cheap HSS step bit on cast iron, and once I was done two of the steps couldn't even make it through aluminum. I don't often need to drill through butter, so I had pretty much given up on that bit. But after your video it can get through aluminum again. It's not exactly good as new (I think some of the steps have a chipped cutting edge which would require removing a LOT of material), but a lot better than before
Thanks for the tutorial.
try putting the sheet metal againsty a piece of plywood and then hold both in the vise...works waaay better.
This is amazing information
Amazing the technique that you use to sharpen the unit bit, can you please provide me the type of bit you used on the dremel tool.
See video at 2:13. It’s just a cone shaped bit.
Awesome I was just looking at one of mine trying to figure it out.
Awesome! Thanks! 👍
any bit like that should be sharpened with a flat diamond file or stone as you would for a forsner bit. The fly surface need to remain perfectly flat.
Forrest Gump is that you.
.
Lieutenant Dan? It’s been a long time…
They are probably the most expensive drillbits that contractors buy and they’re the easiest to sharpen but people just throw them away.
Thanks for video, liked and subbed...👍👍👍
Thank you buddy!
No problem 👍
Thanks
Son of a gun I never her no one say that accept me the shizzam lol and thanks for the tip I have about 8 of them I was thinking of a way to sharpen I appreciate it
Thanks man
Well when you try to drill a hole with the damn things and thing wont cut for nothing you end up wearing away that top profile and no sharpening will fix that.. like you said.. is a pain in the arse
Yep just hit the like and subscribe button. Thanks
Please comment if this video saved you money.
Cannot understand your convoluted explanation
Then I suggest you go to college and take machine shop like I did.
How do you go about sharpening the tip
Just like you would a standard twist drill, when I first learned how to hand sharpen drill bits in machine shop in college, they gave us a new bit, and had us stick it to a grinder that wasn’t rotating and get our actions down to where we could move our hands throughout the arc to practice. I would suggest getting a new bit and practicing the same way, but be careful because of their awkward shape. I suppose you could also just use a diamond file on it.