Thunderbolt Web, 21 Piece, Jobber Length, Black Oxide Drill Bit Set, Includes: 2 Each 1/16", 2 Each 5/64", 1 Each 3/32", 1 Each 7/64", 2 Each 1/8", 1 Each 9/64", 1 Each 5/32" 1 Each 11/64", 2 Each 3/16", 1 Each 13/64", 1 Each 7/32", 1 Each 15/64", 2 Each 1/4", 1 Each 5/16", 1 Each 3/8", 1 Each 1/2", With Indexed Case, Thunderbolt Web, Provides Longer Life & Faster Driller Times, Parabolic Flute, Clears Chips Faster, 135 Degrees Split Point, Precision Start No Walking, 3 Flat Secure Grip Shank, Reduces Bit Slipping In Chuck, Clamshell Packaging.