It depends on how straight you want it. I recently drilled a pilot
hole thru a block of annealed 4340 just over 2 1/2 inches thick.
Other than using a drill press and getting the drill exactly over the
center punch dent, I didn't do any thing special. I think it was
straight enough for what you want to do.

Dan


Pete & sheri wrote in message

But I am looking for ideas on making the holes
for the #6 and #8 taps really straight. Any ideas? The holes will be
1" deep. I will make my prototype from mild steel, but later, I want to
make some from annealed 4140.

I would appreciate any ideas on making those small holes straight,
Pete Stanaitis