Cobalt steel extends cutting edge life and maintains cutting life after resharpening. Extra hard drill for greater wear. 135 degree split point tip starts on contact, cuts with less force. Rubber overmolded case protects kit if dropped. Tap and Drill selection chart for convenience reference Automatic indexing for easy bit access and identification. Removable cartridges: easy to carry bits from case to worksite. Set contains the following drill bit sizes: 1/16", 5/64", 3/32", 7/64", 1/8", 9/64", 5/32", 11/64", 3/16", 13/64", 7/32", 15/16", 1/4", 17/64", 9/32", 19/64", 5/16", 21/64", 11/32", 23/64", 3/8", 25/64", 13/32", 27/64", 7/16", 29/64", 15/32", 31/64", 1/2".