Dormer E0353/4 Spiral Point Taps, UNF3/4, Full Length 4.1/4"Flute Length 1.1614", Shank Diameter 0.5900" Spiral point and straight flutes for cutting threads in through holes Spiral point pushes chips ahead of tool to reduce clogging Powdered-metal steel for performance approaching that of solid carbide tools, with the toughness and shock-resistance of high-speed steel Gold oxide finish reduces grinding stress within the tool Available in UNC (Unified Coarse) and UNF (Unified Fine) right-hand thread options for different applications