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 29 Piece Cobalt Alloy Steel Drill Bit Set Ideal for drilling in tough metal, including heavy-duty abrasive alloy metal drilling on hardened steel. Made from industrial grade High-speed steel for increased durability. 8% Cobalt Alloy Steel alloy is heat and abrasion-resistant. 135-degree split-point tip starts drilling immediately with less force and eliminates “walking” across the work surface. Metal index case for easy bit access and identification. Includes drill bit sizes 1/16- to 1/2-inch in 1/64-inch increments. IRWIN Tools Cobalt Alloy Steel High-Speed Steel Drill Bit, 29-Piece Metal Index Set (3018002). The Irwin 29-Piece Cobalt M-35 Metal Index Drill Bit Set includes drill bit sizes measuring from 1/16 to 1/2-inch in 1/64 inch increments. The 29 bits are made using heavy duty web construction for strength and durability, and the cobalt steel extends the life of cutting edges. The 135-degree split point tips start drilling on contact and cut with less force. A reduced shank above the 3/8-inch point lets you use larger drill bit in a 3/8-inch chuck, and you can select the right bit using a convenient tap and drill selection chart. The set’s rubber overmolded case protects against damage from accidental dropping, and you can remove cartridges to easily carry bits from the case to your worksite.