The hammer (2) forms part of a striking mechanism (1) of a mechanical watch, which includes at least one gong (11) that can be struck by said hammer. The hammer includes two metal parts (2′, 2″), which are secured to each other by welding or soldering. A first part is made of hard metal to form an impact part (2′) of the hammer against a gong (11) of the striking mechanism. A second part is a metal heel (2″), particularly made of steel, via which the hammer can be mounted on a plate of the striking mechanism.