Drill America DWD60S-SET Qualtech 60 Piece High-Speed Steel Screw Machine Length Drill Bit Set in Metal Case, Black Oxide Finish, Round Shank, Spiral Flute, 135 Degrees Split Point (Pack of 1) High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance Black oxide treatment adds lubricity and creates small pockets on the surface of the tool that act to hold coolant near the cutting edge Round shanks allow use with a wide variety of toolholding systems When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging 60 piece drill bit set comes in a metal case