Thunderbolt, 5/16" Titanium Drill Bit, Skin Carded Packaging, For General Purpose Drilling In Wood & Metal, Excellent For Use In Cordless Drills, Titanium Oxide Coating Provides Up To 3 Times Longer Life Than High Speed Steel Bits, 135 Degree Split Point Tip For Fast Starts With No Walking, Thunderbolt Core Resists Breaking.