Spyder 19022 Mach-Blue 1/4-in 12-Step Drill Bit (3/16-in to 7/8-in)Spyder 19022 Proprietary Mach Blue Armor Plating is a super hard surface plating that retains sharper cutting edges, and reduces heat build up and cutting friction resulting in faster cuts and exceptionally long drill life. Impact rated 1 4 speed hex won't slip in conventional 3 jaw chucks and ideal for use in quick change impacting power tools. Optimized 135 self centering split point cutting geometry won't walk or wander even on pre hardened or