Fitters construct and assemble mechanical systems. These systems could be factory machines or the piping that carries the chemicals involved in the manufacturing process. Some fitters choose to specialize in mechanical fitting, pipefitting, or steamfitting, others work in the heating and cooling industry maintaining and repairing systems in commercial or factory settings. The manufacturing industry is the largest employer of fitters. Fitters thrive on physical, hands-on work in a work environment that doesnt revolve around a desk. Some factories maintain evening and weekend hours, and heating and cooling companies often maintain a 24/7 schedule, meaning fitters may work nontraditional shifts.