butlersrangers wrote on Dec 24^th, 2015 at 5:00pm:

FredC - Your commentary on Springfield Armory threads and Dies is interesting. I assume our U.S. Armories and tooling were influenced by the 'French Arms' we first copied and manufactured.

It could be French, I would have guessed English as the 1917 Enfield has a similar thread to the Krag. I had mine (Enfield) apart so long the screws got lost and I had to make a pair for it. It seems they had the same thread form, without pulling one apart though I can not remember for sure. The Brits also had a Whitworth thread form that had rounded roots and crests but it had 55 degree flanks. If you look at the Krag screw on the optical comparator, they sure look like 60 degree but they have been "pulled" a little.
Not being an expert on the history it could be the Americans copied the French, then the Brits copied one or the other for original P14.

Right now it is just something to be aware of to make a good fitting replacement.

Interestingly the US, French and English governments did work together to establish the Meter. A French tool maker/scientist made the three original meter rods and one was give to each government. Our inch is now base on 2.54cm and the original meter rods replaced as they were not done that well anyway.