These drill bits come in standard sizes expressed in fractional inches. They have a TiN coating that protects them from wear and heat when drilling steel, stainless steel, and aluminum. These bits have spiral flutes that evacuate chips as the bits drill into a workpiece, and they 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 commonly used drill-bit length. They provide a good balance of strength and accuracy when drilling into a range of materials.