Quote:
Originally Posted by Joey Milia
What I did when cutting 1.125 bearing holes in 1/8 wall box beam. Started with quarter, then straight up to 1 inch, the largest drill we have. The pilot should be just big enough for the center part of the 1" drill which is not center cutting. Then I bored the hole to just under, and reamed it by hand to the final size.
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Out of curiosity, why did you ream the hole if you were already boring it? Boring should have given you superior dimensional accuracy.
Quote:
Originally Posted by JCharlton
I'm looking to doing the same, machining 1-1/8 inch holes to a tight tolerance. I've been looking in to either a "sheet metal cutter" which can do 1/4" (e.g. http://www.trick-tools.com/Sheet_Metal_Cutters_81) or an annular cutter with a weldon shank adapter for our R8 mill.
I'd like to know if anyone with machining experience could comment on the above? |
Neither of those is going to give you a press fit. Possibly not even a very close hole to what you want.
The only good ways to get a dimensionally accurate hole to tight tolerances with manual equipment are reaming and boring. Boring is better as it will give you both a straight and dimensionally/positionally accurate hole while reaming will follow the existing hole. If it's not straight, or on location, your reamed hole won't be either.