"Carlos Valor" wrote in message
om...
looking for recommendation on how to drill a 1" deep 5/16" diameter
hole in the end of a steel 5/8" bolt. it is crucial that the hole be
centered and parallel to the bolt axis. i have a small craftsman
drill press, plenty of drill sizes, and a starret auto punch.

the best idea i can think of is to bolt the 5/8" bolt on to the drill
press table and hope the press table is perpendicular to the chuck
axis. got no clue how to find the bolt center so i can punch it.

Here's a trick that I've used with some success, put the bolt in the drill
chuck ! But first you need to get a drill bit clamped very close to
perpendicular. I put the bit upside down in the drill chuck, leaving the
shank exposed. Then I raise the table up so that I can tighten a vise on
the bit (using a spacer as needed). With the drill secure in the vise,
loosen the drill chuck and lower the table with the drill bit. THEN put the
bolt in the drill chuck. If the end of the bolt is not close to flat, then
work it over with a file. Then you have some hope of getting the drill
started in the center. Spin up the drill, and carefully feed the bolt down
onto the drill, trying to find the center. My experience is that with some
practice you can get close, and it's hard to get the bit stared too far off
center as it gets thown aside !

One additional benefit of this method is that chips fall down out of the
hole when cutting brass etc.

I'd not wager much that one can get the hole within 20 thou of center every
time, but it should be pretty parallel, and it's a method you can try with
your drill press.

Good luck,

Dave, from Saskatoon where someone forgot to send summer this year, brrrrr