Drill Bits Cobalt Pro Grade. Cobalt Drills Are Designed To Cut Through Extremely Hard Metals, Including Stainless Steel. No Center Punch Needed: Century 135 Degree Quick-Cut Points Are Self-Centering And Penetrate Faster With Less Pressure, Will Not Walk Or Wander At The Starting Surface. Extremely Heat Resistant, Must Be Used And Operated In Power Units That Have A RPM Speed Of 1.500 Or More For Maximum Efficiency. Aerospace Naps 907-J Specifications. 14X Life Rating, Comparison To The Average 118 Degree Point High Speed Steel Drill. 8% Cobalt.