Union Butterfield HSS Bright UNF Hand Tap ANSI No.1 x 72. The most versatile taps for hand use or machine tapping in a wide variety of materials in through or blind hole applications. Available in 3 chamfer lengths - taper, plug, and bottoming. Taper - 7-10 pitch chamfer length Plug - 3-5 pitch chamfer length Bottoming - 1-2 pitch chamfer length