115 Piece Cobalt High Speed Drill Bit 3-in-1 Set with Metal Indexed Storage Case, 135-Degree Tips 29 fractional sizes 1/16" to 1/2" by 64ths 26 letter sizes A to Z 60 numbered wire-gauge sizes 1 to 60 by 64ths 135 drill tips or Point Angle is designed to drill and withstand very hard, dense materials such as Armor Plate, Nickel Alloys, and Stainless Steel while preserving bit sharpness and usable life. Split point prevents skating increasing alignment accuracy. Be sure to follow "Machine Shop" standards and match: drill speed, material and type of cut, to maximize cutting life of tools.