Actually, it was the British who first standardized fasteners back in the early 1800s. This standardization is known as "Whitworth," after its inventor. Prior to that every machine shop and manufacturer made its own fittings and nothing was interchangable. The threads and pitch on all Whitworth fittings are measured in milimeters, only the heads are sized in inches, as most of the world operated with inches and feet in those days. If the Union blockade had not been so effective the Confederacy would have been able to import many more of the much feared and highly accurate Whitworth cannons from England. Whitworth aventually migrated to being called "British Standard" after WWII and pretty much died out in common useage by the end of the 50's. The second standardization of fasteners is called "British Associated" or BA and is still in use today.
There were two metric systems, "French" metric and "German" Metric, mostly distinguished from each other by the degree of pitch of the threads. The French metric system of fasteners pretty much died out after WWI, except in a few applications in the UK between the wars due to a large transfer of French industrial assets to the UK in repayment of war debt. The German metric fasteners ultimately were more widely adopted simply because the German thread pitch made for a stronger fastener.
- Mike Hughes -ô¿ô-
