Depth of drive adjustment for a fastener driving tool with removable contact member and method of exchanging contact members

A fastener driving tool includes a housing assembly with a nosepiece assembly defining a drive track. A safety trip assembly includes a trigger enabling portion and a workpiece engaging portion and is movable between an extended disabling position and a retracted enabling position. The safety trip assembly is biased toward the extended position and is moved toward the retracted position by engagement between a workpiece and the workpiece engaging member. The workpiece engaging portion is movable to permit adjustment of a length of the safety trip assembly. The workpiece engaging portion may be removed from the safety trip assembly and exchanged with another different workpiece engaging portion. A workpiece engaging portion usable with the fastener driving tool includes a positioning mechanism having an opening locating structure and a guiding structure.