Abstract: A vise jaw is provided which is configured to support a stop to provide precise and secure positioning of a work piece within a vise in both a primary horizontal direction and in a lateral horizontal direction. The jaw includes at least one slot, preferably in the form of a groove, intersecting with a face of the jaw. A stop is provided, such as in the form of a key, which includes a free portion and a captured portion. The captured portion is contoured to fit within the groove while the free portion extends out of the groove and beyond the face of the jaw. A bore in the key can be aligned with a threaded hole in the groove so that a threaded fastener can secure the key within the groove. The free portion abuts the work and resists lateral motion of the work.