Quality product at a reasonable price and very fast delivery. Doesn't have a keyway or set screw BUT you shouldn't have either. If you know how to drill a hole, then you're in luck. Just drill a hole where you need the set screw and also through the shaft you are mounting it on. Then install the roll pin through the gear and shaft. This requires more torque than the screw and will hold the gear in place. You don't have to weld it.