IRWIN Record Chain Pipe Vice rests on a V formed by two sets of drop-forged, heat-treated replaceable steel jaws. The high tensile steel chain is then looped over the pipe, locked into a slot between the jaws and tensioned by a handle and screw to provide a strong rigid three-point location which renders the pipe immoveable. Body castings are guaranteed against breakage.IRWIN Record 182C Chain Pipe Vice. Pipe Capacity: 6-100mm (1/4-4in).Additional Information:• Min. Capacity (mm): 6• Max. Capacity (mm): 100• Min. Capacity (in): 45383• Max. Capacity (in): 4