(Glenn Cramond) wrote in message . com...
"Marty" wrote in message ...
I have to drill a number of flat bottom holes, 7/8" diameter and 1/10"
(.1") deep in some 2/10" (.2") thick aluminum. Is there a source for
flat bottom drill bits of this size that will fit in the 1/2" drill
chuck that's on my drill press? If there are no bits of this size with
a turned down 1/2" shank, can an adapter be purchased to go from the
7/8" bit to the 1/2" chuck? Thanks for any help. Marty

Hi Marty,

Easy one if you can sharpen a drill by hand. It's called Zero Angle
sharpening. I'll put the instructions and a couple of drawings on
www.thepiers.net within the next couple of days.

With Zero angle sharpening I've drilled hundreds of 1/2" holes in 26
gauge material, no burrs. Your only problem may be getting the 7/8"
drill with a turned down shank check out
http://www.precisiontwistdrill.com/t...p/techhelp.asp.

Glenn

The details are up http://www.thepiers.net/pn/index.php...viewtopic&t=73

This will work for you, those suggesting more complex methods should
also go to the "easy way". In stead of drilling right through just
drill a blind hole. set the depth on your drilling machine.

Glenn