Westward Jobber Length Drill Bit: 1/4 in Drill Bit Size, 2 3/4 in Flute Lg, 4 in Overall Lg

These drill bits come in standard sizes expressed in fractional inches. They have a black-oxide finish that retains lubricants to improve the bits' wear resistance and chip flow. Black-oxide bits should only be used for drilling ferrous metals. The bits' spiral flutes evacuate chips as the bits drill into a workpiece. These bits have a straight shank that installs into a drill chuck or similar toolholder.

• Non-coolant-through high-speed steel jobber-length drill bits do not have coolant holes, so a separate hose is required to bring coolant to the bits' tip if it is needed. High-speed steel drill bits provide more flexibility and absorb more shock and vibration than cobalt, powdered-metal, and carbide drill bits, making them suitable for use in manual drilling machines and handheld power tools. They may leave a rough finish on the hole. Jobber-length drill bits are the most co mmonly used drill-bit length. They provide a good balance of strength and accuracy when drilling into a range of materials.