Specification of Our Step Drill Bit : Bit #1 (17 steps): 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8", 15/16", 1", 1-1/16", 1-1/8", 1-3/16", 1-1/4". Bit #2 (9 steps): 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4". Bit #3 (6 steps): 3/16", 1/4", 5/16", 3/8", 7/16", 1/2"