A metalworking vice has two jaws which clamp objects in a parallel motion. The jaws often have serrated or patterned surfaces, in order to clamp onto objects with a firm grip
One jaw is attached to the fixed body of the vice and is constantly stationary. The other jaw is attached to a moveable section which has a machined extension that slides perfectly into the fixed body of the vice. This machined extension is often referred to as the slide.
A threaded screw connects the jaws to the vice handle which can be turned clockwise or anti-clockwise by the user to control the movement of the jaws.
The screw is held within the slide by a long threaded nut. The nut is securely locked and dovetailed within the body of the vice, so that the fixed and sliding jaw are always in perfect alignment.
The screw is rotated by the handle which is fitted in the outer end of the vice. Pressure is exerted by this handle, through the main screw which then adjusts the moveable section of the vice and either opens or closes the sliding jaw.
When contracted, the sliding jaw is then under the control of the slide which is guided back into the fixed body. This draws the jaws back together in a parallel motion around the desired object.
The vice then holds the object securely so that work such as sawing, drilling, or filing can be completed on it.