Tin

Tin is practically never welded, but soft soldered. The solder melts and wets the clean, degreased surface, forming a solid joint, but mechanically it doesn't come close to a weld. For electronics and sensitive components, that's just right, because you don't put heat in like welding. Just make sure the solder flows cleanly, otherwise you'll get cold solder joints. And in severe cold, pure tin can decompose, which is called tin pest – it crumbles into a gray powder.