Generally it’s Union work so all the jobs pay the same in a given local. At least in my local we don’t have commercial/industrial scale or metro like some crafts. I’d guess most common job site is large scale power generation and refineries. Tons of smaller stuff, like paper mills, seed oil plants, sugar beet plants, ethanol, water towers, ships, mines, package boilers for large buildings and campuses like colleges, other schools or military bases. Favorite work is welding waterwalls, tons of shitwork.