IRWIN Drill Bit Set, M35 Cobalt Alloy Steel Steel, 29-Piece (3018002). Cobalt Alloy Steel Drill Bit Set. Sizes 1/16 inch -1/2 inch in 1/64 inch increments, 135 Degree Split Point To Minimize Walk. 5% Cobalt Alloy Steel For Higher Heat & Abrasion Resistance. Heavy Duty Web Construction For Strength & Durability. Anyway, thank you very much, enjoy your shopping.