These screw machine drill with slow spiral type comes in heavy duty grade, solid carbide, bright finish, four-facet point, drill point degree 135, fractional size 17/64", decimal equivalent 0.2656, flute length 1-7/16", overall length 2-5/8", shank diameter 17/64", for aluminum, cast iron, Inconel, stainless steel, titanium and hardened steel under 35 HrC.