Cobalt steel extends cutting edge life and maintains cutting life after resharpening. 135º split point begins drilling immediately, minimizing bit "walk". Rubber overmolded case protects kit if dropped. Sizes include 1/16" to 1/2" in 1/64" increments. Automatic indexing for easy access and identification. 29-Piece High-Speed Cobalt Steel Drill Bit Set, w/Case