Dormer E001 Powdered Metal Spiral Point Threading Tap, Black Oxide Finish, Round Shank With Square End, Plug Chamfer, M16-2.00 Thread Size 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 Black oxide finish improves lubricity, resists corrosion, and helps prevent buildup Plug chamfer for easier starting and correct perpendicular alignment