The Button Head Cap Screw is M4 metric with a total length of 15mm. The threaded portion is 13mm long, the head measures 2mm thick and has a diameter of 8mm. The thread length, or distance of each thread, is 0.7mm. The Button Head Cap Screw works with a 3/32” hex socket. This item is made of iron with a black oxide finish. It is sold singularly, so please choose a larger quantity if you would like extras on hand.