Sheet metal workers manufacture, assemble, install and repair various types of articles and components, such as ducts, control boxes, drainpipes and furnace casings, out of sheet metal less than three millimetres thick.
Sheet metal workers manufacture most metal components in workshops. They determine the project requirements, including scope, assembly sequences and required methods and materials, according to blueprints, drawings and written or verbal instructions. Gauges or types of sheet metal or non-metallic material are selected, according to the product specifications. They then lay out, measure and mark dimensions and reference lines on the material, such as roofing panels, according to the drawings or templates, using calculators, scribes, dividers, squares and rulers.
Blueprints may need to be converted into shop drawings to be followed in the construction or assembly of the sheet metal products. Patterns need to be developed and laid out so that materials are used most efficiently, using computerised metalworking equipment to experiment with different layouts. Metal material is shaped over anvils, blocks or other forms, using hand tools. Holes are drilled or punched in the metal for screws, bolts and rivets. Seams or joints are fastened together with welds, bolts, cement, rivets, solder, caulks, metal drive clips or bonds to assemble the components into products or to repair sheet metal items. They trim, file, grind, deburr, buff or smooth surfaces, seams or joints of assembled parts, using hand tools or portable power tools.
Individual parts, assemblies and installations are inspected for conformance to specifications and building codes, using measuring instruments such as callipers, scales and micrometers.
Prefabricated parts may be transported to construction sites for assembly and installation, or parts at the construction sites can be fabricated or altered, using shears, hammers, punches or drills. Assemblies such as flashing, pipes, tubes, heating and air conditioning ducts, furnace casings, rain gutters or downpipes are installed in supportive frameworks.
They make and install sheet metal ducts for high efficiency air-conditioning, heating and ventilation systems. They make and install metal for kitchen walls and counters and stamped metal for roofing and siding. Roof panel edges and machine-made moulding are fastened to structures, and the pieces nailed or welded into place. They install the roof gutters and downpipes for rainwater drainage and make skylights and vents for industrial buildings.
Sometimes a product has to be treated against rust by galvanising, tin-plating or treating with certain chemicals.