S & D (step) shanks fit 1/2in. drill. Bit sizes: 17/32, 9/16, 19/32, 5/8, 21/32, 11/16, 23/32, 3/4, 13/16, 7/8, 15/16 and 1in.. Key Specs Includes (qty.) 12 Shank Diameter (in.) 1/2 Size 17/32, 9/16, 19/32, 5/8, 21/32, 11/16, 23/32, 3/4, 13/16, 7/8, 15/16
