Check the listing for details. CLE-LINE C74040 Jobber Drill,4.60mm,HSS 407G97. Condition: New. Listed at 3.76 USD. Jobber Length Drill Bit, Drill Bit Size 4.60 mm, Drill Bit Point Angle 135 Degrees , High Speed Steel, Black & Gold, Decimal Equivalent 0.1811, Metric, Drill Bit Point Type Split Point, Non-Coolant Through, Number of Coolant Holes 0 The black-and-gold finish on these drill bits lubricates the bits and provides some resistance to wear and rust. These bits have spiral flutes that evacuate chips as the bits drill into a workpiece. They also have flats on their shank that help prevent the bits from slipping in a drill chuck when drilling at high speeds or under heavy loads.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.