1/2" body 90° micro stop countersink, 1/4-28 thread.
A micro stop countersink screws into a micro stop cage, which sets the depth mechanically so every seat comes out the same — the standard way of countersinking for flush fasteners in aerospace work. The cutting body is 1/2" at a 90° included angle, on a 1/4-28 mounting thread.
It takes pilot pins from .0938 to .1285", so one cutter covers a range of hole sizes: change the pilot, not the tool.
Available in 2, 3 or 4 flutes and other pilot ranges on request.