I don't know if this is a common problem, but i have these on both of my basses, and one of the arms that attaches to the actual body of the instrument is starting to show some sort of blemishing, like metal does before it rusts, it is literally only one of the arms out of 4 i have so i think it was just a random thing. The problem is that it makes it so my strap doesn't just spin free in it so the screw keeps getting loose, and one time (the first time) i didn't notice and it actually fell out. Notice i still like the product, this was just one of those things i think, so I would still recommend it.