The #79 mini heavy-duty automatic center punch can punch, mark, scribe and start drill, nail or screw holes. features: it is ideal for machinists and automotive repair pros. One-handed spring impact operation; no hammer needed. Spring tension adjusts for light or heavy strokes and marking. All-steel body with knurled finger grip, and rust-resistant black oxide finish. Replaceable hardened steel point #79p or #79p/2.