What Marv comes closest to describing in commercial version are a notched shaft corresponding to hole diameter, and a cutter with a female opposite of the notch; basically a bayonet fitting. They are called back countersinks, in concert with back spotfacers and counterbores. Very common in certain castings, and lots of aircraft forgings. These are important when a fastener needs a flat seat close to a wall, impeded by a fillet or radius.

They run easily in a sturdy drill press or milling machine, and a quill stop makes depth control very simple.