Staff Sgt. Todd Mathis, a metals technology craftsman from the 379th Expeditionary Aircraft Maintenance Squadron Aircraft Metals Technology Shop, uses a tungsten inert gas welder to bond two aluminum pieces together. Known as Metals Shop, their mission is to support aircraft and air ground equipment with skills in metal work; the only shop capable of working and welding exotic metals such as titanium, cobalt and nickel alloy. (U.S. Air Force photo/Master Sgt. Brendan Kavanaugh)