Originally Posted by
Ancient Mariner
As I understand it, it has to do with the precision (roundness) of the ball. 25 is the best that is commonly available. In this case, 300 is not better, even though it sounds like it should be.
I picked up grade 24's from one of the online hardware suppliers that was linked from one of the threads here, I think the next best bearing ( lower # ) was ceramic.
Glenn