Drill America DWTET Series Qualtech High-Speed Steel Extension Pulley Tap, Uncoated (Bright) Finish, Round with Square End Shank, Plug Chamfer, 7/16"-14 UNC, 6" Length (Pack of 1) Extension tap is used for tapping the hubs of pulleys for oil caps or set screws. The long shank is also ideal for reaching holes inaccessible with standard length taps. High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance. Uncoated tools feature just the base substrate without any additional treatment or coatings and are suitable for a wide range of applications. Round with square end shank. Right-Hand cut tools have a cutting action that engages when they are run in a clockwise direction.