What is the thread depth on a K-frame S&W barrel?  Alternatively, what is the diameter of the unthreaded portion that is next to the cylinder?

The outer diameter next to the cylinder is 0.500", length of the unthreaded part is 0.131; the thread diameter is 0.542" and it's length is 0.536 with an unthreaded shoulder that is 0.050" in length.
These measurements are from a Model 53 6" barrel from the early 1960's.