Premium Sub-Micrograin Solid Carbide Stub Length Drill Bits2 Flute15° Helix135° Split Point Stub Length These drill bits require rigid toolholding and workholding to be run properly and avoid breakageALTIN Coating: A high performance coating for drilling stainless steels, carbon steels, alloy steels, and cast iron.15/64 Carbide Drill Screw Machine Length ALTIN Coated As with all of our solid carbide tools, these drill bits are manufactured using state-of-the-art machinery, manufacturing processes and inspection techniques, making them the preferred choice of solid carbide drills for machinists wanting to produce high quality parts with maximum tool life.