The screws that come with the strap locks are not the same size as the stock screws on most guitars. To get them installed, I had to file down the head of my stock screws (I can confirm this for Spector, Ibanez, and Dean basses). I would suggest that method as opposed to other suggestions I received of "drilling" the hole out in my bass. Needless to say I'm still a bit ****** off about the needed adjustment that seems to stem from a design flaw.