From the Manufacturer

Use automatic center punches to precisely punch material for drilling and layout work. Spring operated tool drives hard point in a single one-handed operation that eliminates striking a punch with a hammer. Spring tension cap can be adjusted for light to heavy strokes. Punch depth can be set for repetitive work. This is a steel automatic center punch for making lighter markings than #78. It has a black oxide finish that inhibits rust. The all-steel body is 5" with threaded, replaceable hardened steel point and shaft. The body diameter is 1/2".
Sold as 1 Each.
Tip Type: Pointed Tip. Spring tension adjusts for light or heavy markings. Pointed Tip.
Material: Steel. Ball bearing action. Punches, Marks, Scribes And Starts Drill,Nail Or Screw Holes. WARNING: This product can expose you to Nickel, a chemical known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.
Punches, marks, scribes and starts drill, nail or screw holes. Black oxide finish inhibits rust. Spring Tension Adjusts For Light Orheavy Markings.
One-hand spring impact operation, no hammer needed. All steel body with threaded, replaceable hardened steel point. All Steel Body With Threaded,Replaceable Hardened Steel Point.