Pressing gas cylinder concave bottoms - GIF

[hemmjo]

Love to see the whole process. Does that start as pipe and they form the end closed? Or start of flat and pressed into cylinder shape?

Found this.

[Frank S]

Love to see the whole process. Does that start as pipe and they form the end closed? Or start of flat and pressed into cylinder shape?

Found this.

For those interested here is the complete start to finish video of an oxygen cylinder being made. In this video however these are made of aluminum ,different factories have a slightly different process, this is just one example. Steel cylinders are heated to much higher temperatures and the starting slug may initially be nearly white-hot while being pressed into shape