Armour-plated, high speed steel (HSS) bits are high performance metal and wood drilling bits that provide exceptional quality and durability and drilling performance. Mach-Blue armour plating, combined with the advanced M-series alloy tool steel construction and proprietary heat treatment, retains sharper cutting edges for longer, have reduced heat build-up and cutting friction, and increased durability, rigidity, and breakage resistance. Impact-rated 1/4" speed hex wont slip in conventional 3-jaw chucks, making them ideal for use in quick-change impacting power tools. High-Speed Steel Hex Shank 2mm-10mm Dia. Drill Bits Suitable for Wood, Drywall, Plastic, Metal, Non-Ferrous Metal & Stainless Steel Bi-Metal with 8% Cobalt Tip Can be Used with Rotary & Impact Modes High-Speed Steel Hex Shank 2mm-10mm Dia. Drill Bits Suitable for Wood, Drywall, Plastic, Metal, Non-Ferrous Metal & Stainless Steel Bi-Metal with 8% Cobalt Tip Can be Used with Rotary & Impact Modes