Form precise square mortises in hollow metal doors without cutting, drilling, or weakening the door structure. Insert this hardened steel tool into the lock bore, tighten the grade 5 bolt, and the door metal forms around the die to create a perfect mounting surface for your latch or deadbolt.
The tool automatically marks screw locations with center punches. Works on edge-seamed doors (not center-seamed). Accommodates 2.25" x 1" and 2.25" x 1.125" face bolts. Black oxide coating resists rust. Made by SPC - the original manufacturer for over 35 years.