Drill America KFDML series Killer Force mechanical length heavy duty drill bit. Manufactured from premium grade High-Speed Steel, it has a heavy duty 135 split point for self-centering and reducing thrust. Gold and black surface treated for use in stainless steel and other hard metal drilling. High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance. 3-Flat shank to more securely hold in your chuck. When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging.