I sent my drawing to a machine shop. It is a pinion gear with a m3x3 set screw locking on the motor shaft. The machined part comes with a m3x3 set screw hole but it is too lose. I need it more tight fit. How can I represent it to the machine shop? They are asking me the number. I understand it is impossible to explain how tight I need here. But let me try here I want to screw in the M3x3 set screw with a little force. So the set screw is not easy to come off when spinning. Please teach me how to represent this to machine shop. thanks