In article , Glenn wrote:

"Frank J Warner" wrote in message
news:210520060941588936%warnerf@veriSPAMMERSDIEzon .net...
I broke the last one my father made, and he died four years ago. I
never watched him do this, so I'm clueless. I've got most of his tools
but really miss his 40+ years of experience.

What are the methods/tools/procedures needed to make a piloted
counterbore out of a standard HSS twist drill?

The pilot will be for a 4-40 clearance hole (.106") and the counterbore
for a 4-40 buttonhead torx screw (approx .210" or 7/32").

Google was no help, or I didn't use the right key words.

The way I make them if I don't have the size I need is to chuck the
appropriate drill in the lathe and grind the pilot to size with the tool
post grinder. Then I take it out and hand grind the flutes to sharpen it.

Glenn

I knew it involved the tool post grinder, my least favorite tool. Oh
well, I guess i'll mount it up and see what happens.

-Frank

--
Here's some of my work:
http://www.franksknives.com