The Yost Vises 34C 6-inch utility combination pipe and bench vise are made from 65,000 PSI Tensile Ductile Iron body parts. It has hardened, replaceable steel pipe jaws as well as hardened steel flat serrated jaws and continuous rolled thread on the main screw. The pipe jaws are set back to allow for the machinist's vise use. This utility combination pipe and bench vise has a 360-degree swivel base and mounts to a workbench. The 360-degree swivel base features 2 lockdowns. Hand-tightening the lock knob on the base secures its position. The tool is designed to help prevent pipe marring, crushing, or bending while you work on it. This tool Conforms to Fed. Spec. GGG-V-410B Type IV and meets NSN 5120-00-293-0110 standards.