Overview Reviews Product Description Cobalt drills offer increased hardness, toughness and better wear resistance compared to regular HSS Gold oxide surface finish provides a polished finish and prevents chip building, galling and welding on a workpiece 135° Degree split point for fast penetration and accurate starting (self-centering) which eliminates "walking" and reduces the thrust force needed Longer overall length but shorter flute length for maximum rigidity Used where extra reach is required or for drilling holes in hard-to-reach places Ideal for low carbon, stainless steel and other ferrous metals. Clarkson Osborn Catalog Product Videos Custom Field Diameter 17/64" Flute length 2-7/8" Overall length 6" Package quantity/sold as each 1 Product Reviews Write a Review Write a Review × Clarkson-Osborn 17/64" Cobalt Aircraft Extension Drill Bit DR64517 Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Review Subject * Comments *