Accusize - 8 Pcs/Set M35 (HSS+5% Cobalt) 1/2'' Shank S&D Drill 9/16'' to 1'', H516-6507 Silver &amp; deming drill set in a fitted plastic box Size: 9/16&#034;, 5/8&#034;, 11/16&#034;, 3/4&#034;, 13/16&#034;, 7/8&#034;, 15/16&#034;, 1&#034; With aggressive 135 split points, these cobalt drills bits not only last longer while drilling but also cut faster than standard high-speed steel bits. It&#039;s ideal for drilling cast iron, heat-treated steel, stainless steel and other hard materials. Straight shank with 3-Equal-Flats to fit 1/2&#034; chucks All sizes 6&#034; overall with 3&#034; flute length Gold and black color 135 split point for fast penetration and accurate starting with no punch. Retains hardness at high temperatures. Lasts 12x longer than standard 118 point drill bits