Abstract: The invention concerns an adjustable precision grinding and machinist vise which has a novel mechanism for precisely clamping metal pieces, tools, and other articles between a movable jaw and a stationary jaw. The vise is made such that it can be mounted on larger machines such as lathes, drills, milling machines, surface grinders and the like. The device employs a series of notches in the base as a guide means to stabilize clamping. A pin engages, at its lower end, a guide with opposite flanges which guide also has a central wedge with an arcuate load bearing surface. The pin extends through a rotatable clamp disposed within an angling shoulder on the movable jaw. The pin is disposed through the movable jaw and into a chamber in the base for engagement in the guide means to thereby insure precise positioning.