Re: Small drills



Bullseyebry wrote:

Hello All,

I am looking for a small drill, that will be used on a "Swiss" C.N.C.
The material is 303 stainless, the toerance on the hole is .0165 -
.0170, and the depth is .056 dp. + - .001. The ones I have tried are
breaking in an inconsistent manner. I am using a Titex which is o/s,
and we are having to stone off .0002, off the o.d., with an Arkansas
hard stone. We have also tried Metal Removal drills. We are running
this drill at 5800 r.p.m's and a feed per rev. of .0003, pecking at
.005 per. Also, due to the geometry of the part, we are drilling the
larger of the two holes in the pick-up spindle, which is the one in
question. Does anyone make a .0167 drill? Any suggestions?



I'd use carbide if at all possible. "Circuit board drills" with 1/8" shank
are good for a lot of different things. I think maybe the feed of .0003"
per rev may be too high. You might do better with a slower feed, but
a deeper plunge per peck, and still get the same total time per hole.
Of course, higher RPM would be a boon, if you can get it.

Jon

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