This is a Lyman roll pin punch set. These are ideal punches for removing hollow and split roll pins. They have a special rounded nose design for proper alignment of the punch on the roll pin to prevent damage. They are a 4140 chrome-moly steel and through-hardened. Machine knurled grips allows for precise control. There are 4 punches that measure 1/16, 3/32, 1/8, 5/32.