Plumbers install, repair and maintain pipes, fixtures and other plumbing equipment used for water distribution and waste water disposal in residential, commercial and industrial buildings. They are employed in maintenance departments of factories, plants and similar establishments, by plumbing contractors, or they may be self-employed.

Cable television service technicians install, maintain and repair cable and satellite television and Internet signal and associated equipment in homes and commercial buildings. Cable television maintenance technicians maintain and repair cable television transmission and distribution systems and associated hardware. They are employed by cable and satellite television companies.

Telecommunications installation and repair workers install, test, maintain and repair telephones, telephone switching equipment and telecommunications equipment related to transmission and processing of voice, video signals and other data over a variety of media including fibre optics, microwave, radio and satellite. They are employed by telephone and other telecommunications transmission services establishments.

Telecommunications line and cable workers install, repair and maintain telecommunication lines and cables. They are employed by cable television companies and by telephone and other telecommunications services.

Electrical power line and cable workers construct, maintain and repair overhead and underground electrical power transmission and distribution systems. They are employed by electric power generation, transmission and distribution companies, electrical contractors and public utility commissions.

Power system electricians install, maintain, test and repair electrical power generation, transmission and distribution system equipment and apparatus. They are employed by electric power generation, transmission and distribution companies.

Industrial electricians install, maintain, test, troubleshoot and repair industrial electrical equipment and associated electrical and electronic controls. They are employed by electrical contractors and maintenance departments of factories, plants, mines, shipyards and other industrial establishments.

Electricians in this unit group lay out, assemble, install, test, troubleshoot and repair electrical wiring, fixtures, control devices and related equipment in buildings and other structures. They are employed by electrical contractors and maintenance departments of buildings and other establishments, or they may be self-employed.

Welders operate welding equipment to weld ferrous and non-ferrous metals. This unit group also includes machine operators who operate previously set up production welding, brazing and soldering equipment. They are employed by companies that manufacture structural steel and platework, boilers, heavy machinery, aircraft and ships and other metal products, and by welding contractors and welding shops, or they may be self-employed.

Ironworkers fabricate, erect, hoist, install, repair and service structural ironwork, precast concrete, concrete reinforcing materials, curtain walls, ornamental iron and other metals used in the construction of buildings, bridges, highways, dams and other structures and equipment. They are employed by construction ironwork contractors.