Posted by David Sherman on Sunday, December 31, 2006 at 01:30:11 :
In Reply to: Good info David posted by David on Sunday, December 31, 2006 at 01:07:03 :
One extra thing. As far as I know, Woodruff keys are always made to the finished size and don't require hand-fitting, but square key stock is typically made a bit over nominal size, something like .003 over, if my memory is right. This is to ensure a tight fit, but it also means that it's standard procedure to have to hand-fit (by filing or very lightly grinding)the key to fit the shaft. On a light-duty shaft that only turns one way, and with a setscrew holding the key down, a loose fit doesn't hurt much, but on a larger piece of machinery, especially if the rotation changes direction or there's a lot of vibration, it's important not to have any slop in the key that would let it pound back and forth. Before filing the key, though, use a small file to clean any burr off the lip of the keyways in case that was what was making it tight.