Bordo UNF Carbon Hex Die Nut

UNF = Unified National Fine

This thread is described by its major diameter and the number of threads per inch of length (TPI). When used on external threads this series has greater tensile stress area than coarse threads of the same size. Fine Series threads will resist stripping out better than coarse threads in areas where the external and mating internal threads are subjected to loads equal to or greater than the capcity of the screw or bolt. Fine threads are also used where the length of engagement is limited 1-1/4 or where wall thickness demands a fine pitch.