Tuff Stuff, CB13PCMC, 13 Piece Cobalt Drill Bit Set 1/16" To 1/4" Metal Case: 1/16", 5/64", 3/32", 7/64", 1/8", 9/64", 5/32", 11/64", 3/16", 13/64", 7/32", 15/64", 1/4". Cobalt Steel - Withstands abrasion and heat generated by hard to machine metals. Contents: 1/16" through 1/4" by 64ths. Precision ground, gold finish. For Stainless & Hard Steels, Wood & Plastic. 135° Split point for fast penetration and accurate self centering. Retains hardness at high temperatures. Sturdy metal cases with hinged index. Bits clearly visible with sizes marked on case.