Discussion Starter · #1 ·
I built a little widget a few years ago from 1/4" mild steel. It has a 5/8" hole in it and I now need to revise the design to enlarge the hole to 1-3/8". What suggestions do you have for enlarging the hole? I don't think I can use a traditional hole saw, since they require a 1/4" pilot hole (my hole is already at 5/8"). And I do need it to be reasonably precise so a bearing will snugly fit in the hole (it's a slip fit, not a press fit). In other words, a sloppy cut that ends a few tenths bigger may be a problem. I have a metal lathe, but can't figure out how to accomplish this in a lathe. Or maybe I can do this in my drill press, but again, I'm not sure how and am trying to avoid an expensive tapered reamer bit.