Ok, looked it up. Process to make calcium carbide invented in 1892, home lighting applications
started in 1894, then to bicycles the next year. Union Carbide bought the patents......and the rest
was history. I used to for for UCC many years ago.
So, on welding possible in 1850s and 60s beyond blacksmith hammer welding, near as I
can tell.
Very early bolt making machinery in 1870s. Looks like about when the price started dropping
and standardization would be starting.
http://www.nationalmachinery.com/about-us/history
Whitworth (British thread) standards in 1840s, used in USA to some extent, 55 degree.
US threads of 60 degree form were common, too. Metric standards, also 60 degrees
were standardized in 1898, but not adopted in the USA. Interesting to note that
Mauser bbls are Whitworth 55 deg threads, not metric. SAE threads created about WW1, then
WW2 threw a monkey wrench, trying to build and use weapon systems made with
Brit Whitworth, Canadian (?Whitworth?) and US SAE threads....big PITA for Allies. Unified
Thread Standard created, UNC and UNF (unified national coarse and fine) used today,
along with metric.
I think bolts were nonstandard and expensive in 1850s and 60s, rivets would be way
easier.
We are spoiled. Go and buy a bag of Grade 8 bolts which are totally interchangable
and strong as heck for a low price. The old timers would have loved to have even
the simple, basic stuff we take for granted.
And no dead horses laying in the road, or even horse apples.
Bill