These drill bits have a straw/bronze finish that improves their wear resistance. They also have spiral flutes that evacuate chips as the bits drill into a workpiece.,Cobalt jobber-length drill bits tolerate higher drilling speeds and are harder and more wear-resistant than high-speed steel drill bits. They provide some shock absorption and can be used in handheld power tools. Jobber-length drill bits are the most commonly used drill-bit length. They provide a good balance of strength and accuracy when drilling into a variety of materials.