FredC - The basis of my observations on Krag/U.S. Threads, in that old KCA post, was provided by Mr. Joe Farmer.

IIRC - In a thread on Threads, 'MadFarmers' contributed a 'List of the U.S. Taps & Dies' contained in Ordnance Tool Sets for the 1903 Springfield.

Having noticed some carryover in threads on U.S. Arms, I simply looked at the specifications and matched them to various screws on the U.S. Krag.

(At the time, I was speculating there might be a pre-metric French influence on U.S. Ordnance threads, due to the large number of French Arms we used and copied, during the founding days of U.S. Arsenals).

(Incidentally, It also seems there is some commonality with (non-metric) British Bicycle Threads).

I've long been curious how, seemingly strange, U.S. Ordnance threads came about. I suspect there is a discover-able answer.

It is regrettable that on the KCA Forum there are not "stickies" to make some of these discussions a convenient resource. Also, the 'Search Feature' is poor at locating and finding topics.