Provided is a method of construction of a tungsten carbide/TSP insert for hard facing a wear surface, comprising the steps of forming a tungsten carbide body (12) in a mould. After the moulding step, a channel section slot (24) or pocket (24') is created in the body before it has hardened substantially. The body is then heat-treated to harden it. A TSP body (32) is fitted in the slot/pocket (24/24') so that it is a close sliding fit between the sides (18) of the slot, and is of the same depth as the slot. The TSP is (preferably) brazed into the slot. The insert has pips (30) on its edges (18) to facilitate welding to a substrate prior to a final brazing step.