I used these to repair the top roller on a belt/disc sander. The bronze bushings on my grinder are worn on the top pulley. I replaced them with these roller bearings and they work great. I'm a little worried about how long they'll last in this type of environment, but they work much better than bushings, and they're cheap enough that I'll probably replace them with a new set if they're ever due to dust and dirt. So far I am very impressed with them.