Im no expert on this subject but I do know: dont peck when drilling SS. Pecking works on aluminum but SS surface hardens. Ive used acetone to cool when drilling SS and go steady with no stopping. How thick?

 

Hard and slow. If you don't see chips coming off, don't keep drilling because all you are doing is work hardening it at that point. Push slightly harder and pulse the trigger if hand drilling, and come off and on the down handle. You don't have to come all the way off the metal, but you want to remove the friction.

 

I've only been successful with a very low speed, under 100 RPM. Lots of pressure, lots of lube (for cooling). Small holes with hand drills it just means lean on it with full weight and use a variable speed so you can go real slow. For big holes I use a electrically-variable-speed gear-head drill. A standard drill press is probably never going to make you happy. You might try a small hole first and step your way up, that will help quite a bit, but takes a lot longer and can leave you with holes that aren't quite centered

 

Somewhere in this forum proper technique for drilling is explained. Pilot hole stiff enough to survive pressure, small enough to drill fast. Next bit has a center core measurement a bit smaller than the first hole. Use these increments. I made the mistake of going up in 1/16 increments. Don't do that.

 

cobalt drill bits and keep em cool i use water alot of times, lube it a little better but lots of stainless driling i dont want the mess

 

My neighbor died many years ago. He knew things about metal I will never understand. He got his start in the shipyards in WWII. He assured me you can't drill stainless without using beeswax as a lubricant. Something about it drawing away the heat from friction. I don't pretend to understand why, I can attest that it works. Good bits, beeswax, low speed, and lots of feed pressure.

 

High pressure, low speed and anchorlube.

 

I dont think Ive seen a one speed drill press. Are you sure it doesnt have pulleys at the top?

What Chad said in post #4, drill pilot holes about half the size of finish hole will help.

 

I dont think Ive seen a one speed drill press. Are you sure it doesnt have pulleys at the top?

It does, but it doesn't slow the spindle enough to justify the hassle. Thanks for all the replies; the metal is just thin sheet metal, maybe 10 gauge.

 

Slow, hard, and lube. (Yes I know the joke writes it self)

 

Crisco. I've drilled a zillion holes in 316-317 and their L variants.

 

My partner and I taper pinned a paper machine. That's 6 or 8 inches of stainless steel in place. Use cobalt drills, not so much because of the better steel, but the split point. Once started never stop. You can't use too much pressure. We would use a 2x4 and rope for leverage. We smoked a few drill motors, though. They ended up taking us off it, because it was a cost/plus job.

 

Was Honey BooBoo there for the event ?
Man. Stainless is finicky but no need for a posse force to put a hole in it.......LOL

 

An old plant I used to work in we drilled 1/2" holes through 10 gauge 304 sheets with 1/2" step bits. We used wax and drilled close to a hundred holes per bit. Sometimes more sometimes less. Depends on how easy you were. Let the bit do the work, once it starts cutting it cruises right along. This was by hand though, not with a press.

 

Using high-speed steel drills in 304 stainless, the cutting speed should be 40-60 surface feet per minute. RPM=cutting speed x 4/diameter.

60x4/.5=480 rpm
60x4/.38=630 rpm


A 1/2 in. drill should be run at less than 480 rpm in stainless, 3/8 under 630 rpm. Any faster and the edge of the drill will break down very quickly. Use plenty of cutting oil and enough pressure to keep the bit cutting.

 

Steve Shimanek

From AS - you have few-new tool resource choices . . . so you have to get it right
with what you have . . .


Mrwhoopee

First - Welcome . . .

Using high-speed steel drills in 304 stainless, the cutting speed should
be 40-60 surface feet per minute . . .

RPM=cutting speed x 4/diameter . . .

Any faster and the edge of the drill will break down very quickly . . .

[For the lay driller - SF/M is the circumference distance traveled 'outer cutting edge'
as if it was traveling straight].

Now: that you have broached speed - you have to introduce 'everything behind the
curtain' . . . equally important - feed . . .

Drill/drilling started with steel - hence the AISI [American Iron & Steel Institute]
pioneered & leads material science in cutting virtually all material developed from
steel forward.

These standards are most availably found in MACHINERY'S HANDBOOK - INDUSTRIAL
PRESS - since 1914 - now in its 30th edition.

This book is so integral to Machine Operations [drilling] the center-drawer in the top
box - of machinists tool boxes - is sized/dedicated for this book.

The drawer comes equipped with a hole in the bottom - to fingered up - this book.

All metal fabricators [regardless of level] should have have this book in their arsenal -

Don't buy new [100.00$+] - buy used [10/20$] - any edition from the 1960's > is still
current for [welding] drill and tapping operations . . .


Opus

 

I used to work with stainless in the pig barn from time to time. I used Cobalt or zirconium nitride coated bits (in many cases I preferred the latter), I also kept it lubed with WD-40 for cooling... not because it's any better than what has been suggested, but it worked for limited drilling.

 

At the copper smelter where I worked as a Machinist we had one job that was a "fluffer" plate for part of the concentrate feed system. This plate was 3/16 or 1/4 316L stainless & had something just short of 1100 1/16 holes spaced 1 inch apart. It was set up on the 4 ft Radial drill, grab a couple of packs of HSS bits and go to town, we would get around 15 to 20 holes normally, I don't remember the speed & feed we ran but always used soluble oil for coolant.

 

Any work you do on stainless just remember to remain aggressive. Any hover time whether it's drilling, milling, or turning will work harden the piece.

 

I recently drilled close 20+ 5/16" holes in 1/4" stainless plate, and it was a learning experience. I'd worked with stainless a few times before, but only drilling a hole here or there. As mentioned, you have to keep a lot of pressure on the cut and keep the speed slow. I used a cobalt bit, and lubed/cooled with old oil...last cut took same amount of time as the first, just don't expect it to drill as quickly as mild steel.

 

We used to drill a lot of holes in 16 to 11 gauge SS. We found that breaking off a 1/8" drill bit so it stuck out of the chuck 1/2" worked well. We could really lean on it. We also used an air drill and pulsed our way through so we didn't work harden it.

 

What livefast1 said. Once you start drilling, don't let off the pressure until you're through. Skid the bit, and you and the bit and the hole are all screwed. Same deal with sawing stainless. Miserable stuff!!