Examples from the Web for centre punch
Split the metal down to the centre-punch mark as shown in the sketch.
Centre-punch: You will find the centre-punch a most useful tool to have on hand.
Taper the iron between the centre-punch mark and the crotch so that when finished the leg should measure 11⁄2 × 5⁄8 in.
This time fuller only two sides, the two sides opposite the centre-punch mark.
Punch a hole with the eye-punch where the centre-punch was made.