Abstract: The invention relates to a lifter bar intended to be mounted internally in a rotating mill drum for grinding ore and minerals. According to the invention, the upper portion of the lifter bar has a carcass of metal, comprising an elongated forward wall element facing in the direction of movement of the wear element, an elongated rear wall element and between these two wall elements transverse wall elements, the wall elements of the carcass defining between them a plurality of spaces, which are at least partially filled with a filler of another material than any of the components of the mill charge, and of greater abrasive specific volume loss than the metal of the carcass.