pic: Wheel problem.

[artdutra04]

Why are people tapping the wheels for #10 hardware?

The specs on the wheels say the six holes should be 3/16", or just barely smaller (.0025") than #10 close fit tolerance. In real life however, it seems that everything on the KoP wheels is about .05" larger than the posted specs. Checking the wheels on calipers reveals the six holes to have a diameter of about .17", which is #8 clearance but is too large for #10 tapping!

#10/32 should be tapped with a .159" (#21 drill) hole, and #10/24 should be tapped with a .1495" (#25 drill) hole. And without reaming the hole larger to #7 drill (.201"), you cannot tap for 1/4-20. I'm halfway amazed you were even able to get threads to stay in after tapping these holes.