Not sure where you find those for $10, I picked up a cheap set at Northerntool up here (this set is now discontinued). Took one look at the cheap Chinese cast iron and the hardened steel caliper bolt I was trying to get off. Knew I was about to see something real special. After the tool snapped in half, I returned it. Only tool I ever returned after using it. These should work great on the cheaper quality pinball nuts, but if you want to use it on harder steel I would recommend getting one of decent quality.