I'm after some tips from any of you craftsmen regarding recessing around a drilled hole. My problem is this - I've made a few pairs of scales for Feather and now Kai folding razors and use a Chicago type screw at the pivot end. The screw itself is 4mm with one end cap of 9mm and the other at 8mm so I like to recess the domes of the end caps which is easy enough using a recessing bit. The problem I have is in ensuring that the recess is central over the 4mm drilled hole - up to now I've positioned the screw and drawn round the cap then recessed the piece by eye - can anyone suggest a more accurate method?