Grace USA 7 Piece Roll Spring Punch Set is manufactured from the highest quality High Carbon Molbendenum Tool Steel and properly heat treated to ensure long life of the punch. Each punch is hardened the entire length with tempered striking end and are centerless ground for complete accuracy. Grace USA has incorporated a reverse taper from tip of punch to help prevent punch from sticking in the work piece. The pilot point (ball on end) that fits into the hollow center of the roll pin helps prevent damage to wall of hole and pin and gives added control for driving roll pins in or out. The Grace USA Roll Pin Punch has three identifying machine marks to help distinguish between regular pin punches. Punches are manufactured from hex stock vs. round which helps stabilize punch from rolling away from user.