Self feed spade bits Size Overall length 1/4 6 5/16 6 3/8 6 7/16 6 1/2 6 9/16 6 5/8 6 11/16 6 3/4 6 13/16 6 7/8 6 15/16 6 1 6 1 1/8 6 1 1/4 6 1 3/8 6 1 1/2 6