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. Drill Bit Size / 1/2 in Decimal Equivalent / 0.5000 Measurement System / Fractional Inch Material - Machining / High Speed Steel Finish - Machining / Black Oxide Drill Bit Point Angle / 118 Degrees Drill Bit Point Type / Conventional Point Coolant Fed / Non-Coolant Through Flute Type / Spiral Number of Flutes / 2 Flute Length / 4 1/2 in Maximum Drilling Depth / 2 in Helix Angle / 28 Degrees Cutting Direction / Right Hand Spiral Direction / Right Hand Shank Type - Machining / Straight Shank Dia. / 1/2 in Shank Length / 1 1/2 in Overall Length / 6 in Depth:Dia. Ratio / 4xD Drill Length Class / Jobber Length Drill Point Length / 0.1502 in Drill Bit Grouping / Individual Series / 150 Drill Diameter Tolerance / +0.0000 in /-0.0010 in Material Grade - Machining / General Purpose Primary Material Application / Cast Iron, Steel Primary Material Application ISO Code / K, P