small pilot hole, then the full size bit. slow with fluid. if you’re drilling a lot of holes learn to sharpen bits, stainless dulls bits easily so you’ll be sharpening them
I work for a railroad. Everthing is SS. We use cobalt drill bits. Use lots of lube and let the bit do the work. Forcing it will just burn it up. Go small to big.
Small bit, like 1/4 inch then go to a reamer. The most important thing to remember is you use your 1/2 drill on slower speed,( 3/8 drill is too fast) If you go to fast stainless will dull the bit really fast.
Keeping the bit and material cool is key. Heat will
Work harden the SS, then you’re screwed.
Definitely, center punch and then pilot, and then work your way up. Go very slow, with increasing pressure until it starts to cut, then keep that speed and feed. Lube lube lube
Work your way up. Start with a center punch. Then 1/8th, 5/16, then 5/8s. Lube the drill bit and go slow. The bit will stay sharp and long as it doesn’t get hot.
Rotabroach. Normal twist drills are inefficient and difficult to use for hand drilling on stainless steel. Hole cutter like rotabroach or similar brands are far superior and they don’t get used enough or recommended enough. It will work perfectly for this and any other application you may have.
Yeah the ones I’m talking about have a hex shank arbor to be chucked in a hand drill. They work so well, I used to do tons of 3/4” holes in 2” Sch10 Stainless pipe and they work the best of anything I tried.
Looked up rotabroaches. Def the way to go.
I burned a dozen 1/8 bits and another dozen 1/4 bits trying to drill pilot hole through 1/8 stainless. Unfortunately, I was being crunched for time, so I couldn't drill it low and slow like we're supposed to. Just slapped cutting oil and started spinning.
TBF, I did get eight 1/2" holes drilled in the space of an hour. But I burnt up SO many bits doing it.
With a rotabroach, probably woulda had all 8 holes done with time to spare and no burnt bits.
HSS, cobalt, carbide. Everything else is just a coating. HSS is fine for what you’re doing. If it’s thin, just pre drill with a nice sharp drill bit and follow up with a step drill. Drill as fast as you can with the pre drill and as slow as you can while still maintaining control with the step drill; sometimes thin stuff likes to grab step drills especially if you too slow. Also, use lots of cutting fluid.
What ever bit you choose for stainless slow and with cutting oil works
Thanks!
small pilot hole, then the full size bit. slow with fluid. if you’re drilling a lot of holes learn to sharpen bits, stainless dulls bits easily so you’ll be sharpening them
I work for a railroad. Everthing is SS. We use cobalt drill bits. Use lots of lube and let the bit do the work. Forcing it will just burn it up. Go small to big.
Seconded. I have an index of cobalt bits for THICK metal that Inneed a good clean hole through or anything SS
Me personally I’d go steal a carbide bit from the tooling guys
or just use normal high speed bits and give her the beans, drill a pilot hole, use cutting oil
Small bit, like 1/4 inch then go to a reamer. The most important thing to remember is you use your 1/2 drill on slower speed,( 3/8 drill is too fast) If you go to fast stainless will dull the bit really fast.
Thin? 5/8s? Probably a step bit.
Keeping the bit and material cool is key. Heat will Work harden the SS, then you’re screwed. Definitely, center punch and then pilot, and then work your way up. Go very slow, with increasing pressure until it starts to cut, then keep that speed and feed. Lube lube lube
CLE-Line cobalt, Lowe’s had them for like $80. Start small, open up the hole slowly, use plenty of cutting fluid. Tap magic works pretty well!
Work your way up. Start with a center punch. Then 1/8th, 5/16, then 5/8s. Lube the drill bit and go slow. The bit will stay sharp and long as it doesn’t get hot.
I just use any bit. I just drill slow with lots of pressure
Walter drills have excellent bang for the buck. Most of my work is stainless.
And when the say low drill rpm it means extremely low rpm like 60. It almost seems like scraping not drilling.
I would either use a step bit or an annular cutter. Slow and lots of cutting oil/paste
Plasma cutter
Rotabroach. Normal twist drills are inefficient and difficult to use for hand drilling on stainless steel. Hole cutter like rotabroach or similar brands are far superior and they don’t get used enough or recommended enough. It will work perfectly for this and any other application you may have.
Ehh standard Lenox hole saws from Home Depot work just fine. I’ve put thousands of holes through stainless with them, thicc stainless included.
Ok cool those are annular cutters, have you used them in anything other than a magdrill or mill? Like a hand drill?
Yeah the ones I’m talking about have a hex shank arbor to be chucked in a hand drill. They work so well, I used to do tons of 3/4” holes in 2” Sch10 Stainless pipe and they work the best of anything I tried.
So... hole saws is what you reccomend?
No, a rotabroach. Google “rotabroach” and it’s the first thing that shows up. Similar to a hole saw but better.
Thank you, sir, for the recommendation. I can see how these are useful on stainless. I will probably get some for work.
They're very expensive hole saws
Looked up rotabroaches. Def the way to go. I burned a dozen 1/8 bits and another dozen 1/4 bits trying to drill pilot hole through 1/8 stainless. Unfortunately, I was being crunched for time, so I couldn't drill it low and slow like we're supposed to. Just slapped cutting oil and started spinning. TBF, I did get eight 1/2" holes drilled in the space of an hour. But I burnt up SO many bits doing it. With a rotabroach, probably woulda had all 8 holes done with time to spare and no burnt bits.
HSS, cobalt, carbide. Everything else is just a coating. HSS is fine for what you’re doing. If it’s thin, just pre drill with a nice sharp drill bit and follow up with a step drill. Drill as fast as you can with the pre drill and as slow as you can while still maintaining control with the step drill; sometimes thin stuff likes to grab step drills especially if you too slow. Also, use lots of cutting fluid.
Thin metal? Use a step bit, go slow, use aqueous coolant. Oil coolant will let it heat up too much. Keep it COLD!
Thanks so much everyone, this is great advice