Union Butterfield 1582(UNC) High-Speed Steel Spiral Flute Tap, Uncoated (Bright) Finish, Round Shank With Square End, Plug Chamfer, 8-32 Thread Size Spiral flute tap design pulls chips back from the tip of the tool and out of the hole to prevent clogging Spiral flutes for creating threads in blind holes Available in UNC (Unified Coarse) or UNF (Unified Fine) right-hand thread options for different applications Uncoated (bright) tools have no additional surface treatment or coating, suitable for general-purpose applications Round shank with square end helps to minimize rotation in the tool holder