An engineer's vise, also known as a metalworking vise or machinist's vise, is used to clamp metal instead of wood. It is used to hold metal when filing or cutting. It is sometimes made of cast steel or malleable cast iron, but most are made of cast iron. However, most heavy duty vises are 55,000 psi cast steel or 65,000 psi ductile iron. Some vises have a cast iron body but a steel channel bar. Cast iron is popular because it is typically 30,000 psi grey iron which is rigid, strong and inexpensive. The jaws are often separate and replaceable, usually engraved with serrated or diamond teeth. Soft jaw covers made of aluminum, copper, wood (for woodworking) or plastic may be used to protect delicate work. The jaw opening of an engineer's vise is almost always the same size as the jaw width, if not bigger.
An engineer's vise is bolted onto the top surface of a workbench,with the face of the fixed jaws just forward of its front edge. The vise may include other features such as a small anvil on the back of its body. Most engineer's vises have a swivel base. Some engineer's vises marketed as "Homeowner Grade" are not made of steel or cast iron, but of pot metal or a very low grade of iron, typically with a tensile strength of under 10 ksi. Most homeowner's bench vises have an exposed screw.