Performs electric and acetylene welding, brazing and silver soldering; repairs, modifies and makes new installations of pipe fittings; performs skilled plumbing work on steam and water lines, medical gases, and related plumbing equipment. Rebuilds fractional horsepower gasoline engines; uses special tools such as valve facers, reamers, cylinder hones, drills and grinders, gauges, micrometers, taps, and dies.