Don’t forget vacuum welding https://en.m.wikipedia.org/wiki/Cold_welding https://en.m.wikipedia.org/wiki/Cold_welding https://en.m.wikipedia.org/wiki/Vacuum_c

Don’t forget vacuum welding https://en.m.wikipedia.org/wiki/Cold_welding https://en.m.wikipedia.org/wiki/Cold_welding https://en.m.wikipedia.org/wiki/Vacuum_cementing https://en.m.wikipedia.org/wiki/Vacuum_cementing The first time it happened it must have been puzzling