I was trying to talk Justin into getting a set of steel tanks so that he could band them together when we got onto the subject of how scuba tanks are made. He mentioned some videos of the process he had found, and sent them along to me. It’s really a pretty amazing process. Especially the way they extrude an entire tank out of a single block of aluminum.
The first video shows how aluminum tanks are made, while the second shows the process for steel tanks.