I have a question on two terms used in defining a new thread.

"Thread Minor Diameter" and "Thread Minor Diameter Inside"

The data for a 1/4-20 from the hole wizard data:

"Thread Minor Diameter" = 0.1905

"Thread Minor Diameter Inside" = 0.1959

I can not find any thread data close to the numbers given above for a internal thread in any of our thread data books.

Is the "Thread Minor Diameter" the theoretical diameter for 100% full thread?

I just need to know exactly how the terms above relate to physical thread geometry.

And where I can find the data or what formulas are used to derive them.

The answer in S-04970: Thread Minor Diameter = the diameter of a cylinder formed by the roots of the threads

Thread Minor Diameter Inside = the diameter of a cylinder formed by the crests of an internal thread

Is unclear at best as to how the number relate to the actual thread geometry.

I forgot to add this image.

Even my VAR can not give me a clear answer as to exactly what Thread Minor Diameter and Thread Minor Diameter Inside are.