What is minor diameter of a 4.5-4 tpi nut?

The minor diameter of a 4.5-4 TPI (threads per inch) nut can be calculated using the formula for the minor diameter of a standard screw thread. For a Unified National Thread, the minor diameter is approximately equal to the major diameter minus 2 times the depth of the thread. The depth of a 4.5 TPI thread is typically around 0.375 inches, so the minor diameter would be slightly less than the major diameter, which is typically around 4.5 inches. For precise applications, consult specific engineering tables or standards for exact measurements.