A wire harness assembly work cell includes a wire harness assembly work table with a pneumatically powered or spring-fed universal applicator tool for mass terminating sets of wires into insulator wafers. The insulator wafers may be assembled in stacks to form cable-end connector headshells. Insulation displacement terminals (IDT) are designed to receive wide ranges of wire diameters so that larger varieties of wire sizes may be received into these connector assemblies while using fewer different sizes of terminals, thus reducing the number of items in a bill of material (BOM) and substantially reducing the volumes and overhead costs of testing and quality control documentation dedicated to each individual BOM item.

A powder-driven connecting tool for connecting power lines is disclosed, as are assemblies and replacement parts for such a tool. The tool includes a tool head with an anvil, and a power unit with a ram. A breech cap assembly connects to the power unit and includes a sleeve threaded on both ends and a cap threadedly mounted on one end of the sleeve. The sleeve and cap define a breech for a powder charge. An adapter is mounted on an outer end surface of the cap. The adapter is narrower than the cap itself and is adapted to be driven by a power tool in order to tighten and loosen the cap and the sleeve. The adapter may, for example, have the form of a hex nut.