People in this group work for construction contractors, sheet metal fabrication and welding shops, manufacturers of sheet metal and fabricated metal products, structural steel, boilers, platework, aircraft, heavy machinery and transportation equipment, sheet metal work, welding, and ironwork contractors, and ship building companies.
The unionization rate (64%) is above the average (32%) for all occupations.
Here are the average annual salaries.
2010: $50,835
2005: $45,011
2000: $35,450
1995: $32,532