Yes. For some reason, the Schallers use a "stepped" hole. Not sure why, as they're retained using a hollow shoulder screw like many tuners do, as well as an anti-rotational or locator screw on the back. But, they want the facing hole a BCH smaller than the majority of the shaft diameter, so it's an unusual rout/drill. They're also tighter than dammit when you install them, which is probably a Good Thing, but it can be a little unnerving if you've never dealt with them before. You think you're going to wreck something getting the little rascals to seat properly, but it just needs the proper tool and they fit up nice.