Button lock

A simple pair of parts to join timber or sheet materials. Invisible joint, strong (>76Kg each) and can be disassembled.
First fit the button hole into a routed slot. The jigs have a 6mm brass insert with a 2.5mm hole for the drill, and a 3mm steel pin reduced to 2.5mm at the end. These slot into the button hole and the pin pushed down to lock them in place. Place this over the other part to be joined and use the jigs to drill the holes for the buttons. They will fit accurately into the slots.
Also included is a round button hole which fits into a 25mm hole 6mm deep.