Sturdy and accurately made machine vice from graded cast iron.* Jaws are made of special tool properly hardened.* Vice can be converted from swivel base to fix by removing the base.* Crank handle is made of unbreakable ductile iron steel providing loaded mechanism providing positive grip.* Fine Acme thread scew & the Swivel base is graduated fully through 360°* Quick alignment to machines through longitude slot provided in base.