This coating is extremely heatresistant and can be used with or without coolant..0000/-.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 stainlesssteels, carbon steels, alloy steels, and cast iron.