Re: Best practice question for drilling holes for metal dowel pins
Drill and ream. Normally you want a tight fit on side and loose in the other. So drill with a 0.234'' (15/64'') and ream with a 0.2495'' or 0.250'' reamer. For the loose side, drill with the same drill and ream with a 0.251'' or 0.252'' reamer. It's best to clamp the die halves together and drill and ream both in one setup, that way you are sure they are in perfect alignment. You will want to drill all the way through so you are able to punch the dowel pin out if needed.
And another hint: make sure the hole locations are not symmetrical. If you locate one 1/4 inch from the edge, then locate the other at 5/16'' or 3/8'' from the edge, that way it's impossible to put the die halves together incorrectly.
Jim Dawson
Sandy, Oregon, USA