Abstract: A fixture is used to cut a mortise in a workpiece for a hinge or lock strike plate by employing a pair of spaced saddles. The fixture includes at least one bar connected between the pair of saddles. At least one of the saddles is slide-ably mounted on this bar. Also included is a pair of clamps, each being mounted in a different corresponding one of the saddles to clamp the workpiece. The fixture is used by clamping the saddles on an edge of the door or jamb with the guide bar spanning the saddles. A mortise is routed into the door or jamb using the saddles as a template.