A vise jaw assembly can be easily mounted on, and removed from, the jaws of a machine vise. A first reusable component bolts onto the face of a machine vise jaw. A second component is inexpensive and disposable. It is made by extrusion of an easily machinable material such as aluminum. It has a flat face that is designed to engage a flat face of the first component. It has an element extending from the flat face such as a dovetail element that slides laterally into a correspondingly shaped recess in the first component to complete a dovetail type joint. A slot below the recess in the first component is compressed by threaded fasteners to tighten the joint. The second component has a uniform cross section so that it may be produced by extrusion with minimal finishing except for cutting to length.