Cobalt Drill Bit Set 31Pcs 1/16″-1/2″, M35 High Speed Steel Metal Drill Bits Jobber Length for Hardened Metal, Stainless Steel, Cast Iron, Plastic and Wood. M35 Cobalt High Speed Steel? Industry grade M35 high speed steel drill bit set, much harder than HSS used in other similar drill bits set. These drill bits contain 5% Cobalt, which increases wear-resistance and durability. Most Commonly-Used 20 Sizes? A complete combo set of 31 jobber length industrial drill bits for metal drilling (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″, 17/64″, 9/32″, 5/16″, 11/32″, 3/8″, 7/16″, 1/2″). They fit the majority of power drill currently on the market and comes with a portable plastic case for easy storage and organization. Precise & Efficient Drilling Performance?? Fully Ground spiral groove design clears particles quickly, decreases friction and heat for a faster and cooler drilling performance. 135° Split Point with round straight shank prevents walking and makes drilling precise and faster. No center punch is needed. Multiple Application? Perfectly suitable for cutting through Hard Metal such as Stainless Steel, Steel, Sheet Metal and Cast Iron as well as Plastic, Aluminum Alloy, Wood and Other Softer Metals. Pay attention to speed, pressure and heat control during drilling.