Here's a short but fascinating video taken inside a chain manufacturing plant, showing chain being made by machine. Watch and you can see that all of the chain starts with two continous strands of wire being fed into the machine, where each is coiled around a wire rod of appropriate size and shape, and fed through a little pincer-type gadget which cuts, grabs, and links to the second wire coming through its own pincer-feed. The resulting chain streams smoothly through the bottom of the machine into a rotating container. Each machine can be calibrated to make variations of chain, with different types of wire thickness, wire flatness, link size and link shape being possible. And of course, the wire could be silver, gold, brass.... A typical chain manufacturer could have more than 50 machines, as each machine can specialize in different chain styles.
