inert gas

Airman 1st Class Thomas Showers, 403rd Fabrication Flight metals technologist, practices tungsten inert gas welding on a piece of stainless steel for his welding certification December 6, 2014. Fabrication flight members build and repair various items and equipment for 403rd Wing shops at Keesler Air Force Base, Miss. (U.S. Air Force photo/Tech. Sgt. Ryan Labadens)