pMorse Spiral Point Tap, High Performance, Series 2088C, Measurement System Imperial, UNF, 91618, Plug Chamfer, 4 Flutes, HSSPM, TiCN Coated, Right Hand Cutting, 0866 in Thread Length, 3937 in Overall Length, Steel, Steel Alloy, Stainless Steel, Titanium Alloy and Materials up to 36Rc Hardness Material Applicationp.