Left-Hand Mechanics Length Cobalt HSS Drill BitTough metal drilling, made for drilling into hardened steel bolts for creating pilot holes for screw extractors. 8% Cobalt alloyed for higher heat and abrasion resistance. Shorter drill for additional strength. Heavy-duty web construction for strength and durability. Cutting Diam: 1/4 in; Cutting Edge Material: HSS-E (Co-M42); Finish: Gold Oxide; Flute Length: 1 3/4 in; Number of Flutes: 2; Overall Length: 4 in; Point Angle: 135°; Point Shape: Split Point; Shank Type: Cylinder; Spiral Angle: CCW; Structure: Solid; Type: HSS Drill Bit; Weight: 0.05 lb.