Stainless steel drilling is testing so use a quality cobalt drill with a quality coolant and use the right drill speed, start small and work upwards. ive used ttp hard drills with success they also sell a desent coolant

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Stainless steel drilling is testing

No it's not. It will work-harden if you dwell on the surface without
cutting, but with a sharp bit and continuous down-feed, it doesn't harden
and drills cleanly and pretty easily.

The number-one reason why stainless gives folks fits is because they
allow the bit to 'spin' on the surface without down-feed. If the drill
ever stops cutting, even for a few tens of revolutions, you're screwed.
If you must retract the bit to clear chips, you must do so _instantly_
from down-feed to retract, so the tip never dwells and slides on the cut
surface.

Of course you need a cutting coolant/lubricant... but why would one cut
without one?

None of that makes it "testing", it only requires the observation of a
few basic requisites for cutting most metals.

Lloyd

On Monday, November 9, 2015 at 1:31:19 PM UTC-5, wrote:
Stainless steel drilling is testing so use a quality cobalt drill with a quality coolant and use the right drill speed, start small and work upwards.. ive used ttp hard drills with success they also sell a desent coolant

DO NOT START SMALL AND WORK UP.

Stainless work hardens. If the final hole diameter is below about 1/2 inch , just pick that drill and drill aggressively. If the final hole diameter is bigger , then you might drill a small hole the diameter of the web on the final size drill, and then go to the final size drill.

Carpenter Tech has an on line book on machining stainless steel. Good info..
If you are into sharpening your own drills the book has info on the best angles for stainless.

Dan

On Mon, 9 Nov 2015 10:31:13 -0800 (PST),
wrote:

Stainless steel drilling is testing so use a quality cobalt drill with a quality coolant and use the right drill speed, start small and work upwards. ive used ttp hard drills with success they also sell a desent coolant
The most important thing is the KEEP THE DRILL CUTTING. Don't let it
"skate" I like using the power feed drill press on stainless - so I
can't do that at home. If I have any serious stainless drilling to dio
I take it to the hangar unless it is something I can do in my lathe -
like drilling the center of a stainless steel bolt. Then I just use
the power carriage feed to pull the tailstock, with the drill in the
chuck. or just crank the quill feed on the tailstock by hand.

On Mon, 9 Nov 2015 10:31:13 -0800 (PST),
wrote:

Stainless steel drilling is testing so use a quality cobalt drill with a quality coolant and use the right drill speed, start small and work upwards. ive used ttp hard drills with success they also sell a desent coolant

I screwed the pooch on the first hole on a stainless box I drilled out
for casters. I didn't have a good position so I couldn't get much feed
pressure on the bit. Luckily, it was a small bit, and a larger one
with mucho downfeed fixed it (blew through the hardened area) I was
able to get serious with the rest and all went well. It didn't hurt
the TiN coated bits.

Serious downfeed pressure, cutting oil, and the proper bit speed are
the 3 tips I would give to anyone. (Having a sharp bit is a 'given')

Some day, I'll put that new idler bearing in my drill press. sigh

--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
-- J. Arthur Thomson

On Mon, 9 Nov 2015 12:34:32 -0800 (PST), "
wrote:

On Monday, November 9, 2015 at 1:31:19 PM UTC-5, wrote:
Stainless steel drilling is testing so use a quality cobalt drill with a quality coolant and use the right drill speed, start small and work upwards. ive used ttp hard drills with success they also sell a desent coolant

DO NOT START SMALL AND WORK UP.

Stainless work hardens. If the final hole diameter is below about 1/2 inch , just pick that drill and drill aggressively. If the final hole diameter is bigger , then you might drill a small hole the diameter of the web on the final size drill, and then go to the final size drill.

Carpenter Tech has an on line book on machining stainless steel. Good info.
If you are into sharpening your own drills the book has info on the best angles for stainless.

Dan

Another tip, don't mark your spot with a center punch. It work
hardens exactly the spot where you're trying to drill.

Pete Keillor