Machinist Tips for Chamfering Some features simply can not be machined with a chamfer mill utilizing only 3 axii. A ball endmill can be used to 3D machine complex features. 5 axis chamfer paths can reach more complex features without requiring specialized tooling. Castings and varying shapes can be chamfered with flexible compensating tools. The best advice I can give the average Machinist is to switch your chamfer mill for a drill mill when necessary. The addition of flutes along the periphery allows for machining into a corner as illustrated.