Gas metal arc welding ( GMAW ) : GMAW is also known as MIG ( metal\/inert gas welding ) . Gas metal arc welding ( GMAW ) , also known as metal inert gas or MIG welding , is a semi-automatic or automatic process that uses a continuous wire feed as an electrode and an inert or semi-inert gas mixture to protect the weld from contamination . Since the electrode is continuous , welding speeds are greater for GMAW than for SMAW .