drill speed for stainless

slow and hard. SS work hardens, you need high feed slow speed. The instant you stop getting a continous chip-STOP! Resharpen the drill and go again. I like oil for SS, I don't use this anywhere else for drilling.

Karl

Depends on diameter, etc. These numbers are conservative for the most part...

ALWAYS use coolant... Motor oil is cheap and works just fine but isn't very environmentally friendly in bulk, etc.

No coolant? Say goodbye to your drills.

Too fast an RPM rate? Same thing... Adios.

Taking shallow cuts? Care to guess the outcome?

Much success to you in the project, whatever it is.

Regards, Joe Agro, Jr. (800) 871-5022

FWIW, there have been scientific studies of stainless-steel work hardening that quantify the whole thing. The work-hardening is severe, and modeling the chip-making in stainless by a conventional drill bit is not easy. But it has been done, and the studies show that it does harden very quickly.

It also heats up, as you say, partly because it's very tough and partly because stainless is a poor thermal conductor. All together, these factors contribute to the difficulty of drilling stainless.

Years ago I drilled many hundreds of 304 stainless parts on a Herbert turret lathe, feeding by hand. One slip, one pause, and you had trouble.

-- Ed Huntress

Thanks a lot. This really helps.