How to cut space for keyhole hanger without a router?

Generally the easiest way to create the deeper recess is by drilling; if you route out the mortise it might seem obvious to use the router

If it's a thru slot, use a saw to connect the two holes If it's a blind slot, drill overlapping holes (ideally with a

how to dimension a slot With aluminum that thin, 116th, you could also use a router with a keyhole bit I've done it many times The bit needs to be carbide You'd need to make a jig

how to pick winning slot machine A few keyholeslot router bits do not come with a plunge capability Do NOT buy that kind You must use a separate drill or plunge bit to make