These drill bits have a straw/bronze finish that improves their wear resistance. Spiral-flute drill bits evacuate chips as the bits drill into a workpiece.,Cobalt screw-machine length drill bits tolerate higher drilling speeds and are harder and more wear-resistant than high-speed steel screw-machine length drill bits. They provide some shock absorption and can be used in handheld power tools. Screw-machine length drill bits are shorter than jobber length and maintenance length drill bits of the same size. Also called stub length drill bits, they provide more strength and rigidity and can drill straighter holes than longer drill bits. Their short length also allows them to access tight spaces where longer drill bits cannot fit.