Joseph Clement's work shows that he was able to
achieve that in the early
19th century. ?It didn't become standard practice until later.
Real mass production? Enough to make a full Engine without having to
pick and choose parts to get them all to work?
The US armories were making pretty good guns with real interchangeable
parts during this period, with the technology becoming child's play by
the mid century. The same can not be said about the British armories.
Guns and clocks are remarkably handy items for benchmarking mechanical
technology. Two very different mass produced precision machines,
basically.
--
Will