What is the minimum pitch diameter for an external thread 7/16-14 UNC - 2A?

For an external thread of size 7/16-14 UNC - 2A, the pitch diameter is a crucial dimension in thread specification that determines how well the threaded parts will fit together. The pitch diameter is defined as the diameter of an imaginary cylinder that passes through the thread profile where the width of the thread and the space between the threads are equal.

In the case of a 7/16-14 UNC thread, the nominal major diameter is 0.4375 inches (7/16") and the threads per inch are 14. The calculations based on the Unified National Coarse thread standard indicate that the minimum pitch diameter for a 7/16-14 external thread should be approximately 0.3850 inches.

Choosing this value as the minimum pitch diameter ensures adequate strength and engagement between threaded components, allowing for proper functionality without risk of stripping or binding. When designing or selecting fasteners, adhering to these standardized dimensions is critical for ensuring part compatibility and performance reliability.

The other options do not fit the requirements set by the standard for a 7/16-14 UNC - 2A external thread, indicating they do not represent the correct minimum pitch diameter as defined by the relevant engineering specifications.