Cold Metal Transfer Welding
A modified GMAW process featuring mechanical wire retraction to drastically reduce heat input and achieve spatter-free material transfer.
Cold Metal Transfer Welding basically means: the wire is mechanically pulled back while the short circuit occurs. This makes the droplet detach cleanly without needing much current – that gives almost no spatter and little heat in the sheet. That's great for thin sheets or when you're worried about burn-through. But watch out: if you don't set the wire movement or arc parameters properly, the transfer becomes unstable. Then you get porosity or a weak weld because the material doesn't melt properly. Set the machine according to the manufacturer's specs and listen for a steady crackling – then it runs stable.