Thanks Ace. I'm probably a bit over the top. For metal, I like a nice tight round hole, not the triangle shape a drill bit gives. So, I typically use a D bit for AN4 then ream. There's also the fact AN bolts are a bit undersized on purpose. My AN3's are .1870 for example, not .1875 (so still can't figure out why they are so tight). Long story short, I'm drilling with undersized bits and now reaming to a size that more closely matches my bolts, not automatically using .250 or .1875 reamers. For AN4, I just ordered a .2480 which is closer to what I have. Oh, I saw at McMaster-Carr, they have a special "Precise" 3/16" bit in addition to regular 3/16". I picked up two of those also (3021A26 Drill Bit for Precise Holes, 3/16" Size).
Thanks!
John |