Knurled Nuts or Thumb Nuts, are round internally threaded nuts with a knurled outside surface, designed to be tightened by hand. Knurled Thumb Nuts are intended for light-duty applications and are available in both Coarse (UNC) and Fine (UNF) thread sizes.
Thumb Nut Diameters
Thumb Nut are available on the FCH Network with Imperial/US diameters that range from #2 to 2 and with Metric diameters that range from M2 to M14. The length of Thumb Nut is usually measured from the point to the underside of the head.