Definition and Nature of the Work

2009-11-09T18:28:00.001-08:00

Welding is the process of heating and melting metal parts to join them together permanently. It is used to construct and repair parts of cars, airplanes, ships, and sheet-metal products. Welding is also used to join beams when constructing bridges and buildings. Some welders work at steel mills, railroad shops, and highway departments. Other welders are cutters, using their tools to cut metal into pieces, as required by a blueprint or design, or to cut structures into pieces so they can be discarded.

Welders are classified as either skilled or unskilled, depending on their training and the kind of welding they do. Skilled welders work from blueprints and written specifications. They know the welding properties of various kinds of metal. Some welders use computers and robots to join metal pieces. With additional training, they can learn to program the computers. Unskilled and semiskilled welders work on projects in home construction, industry, shipbuilding, and other fields. They often work on assembly lines and do repetitive work that requires no special knowledge of welding properties.

There are more than a hundred methods of welding, which use electricity or various gasses to create the high temperatures that bond metals. Arc welding, which can be done either by hand or by machine, is the most common form. In this method, an arc, or electric current, is run through the pieces to be joined as well as a thin welding rod. When the rod touches the metal pieces, a powerful electrical circuit is formed. The high-temperature heat that this produces melts the edges of the metal and the welding rod together. Then the melted metal solidifies to make a strong connection. The type of welding rod used depends on the properties of the metals to be joined and the strength needed for the weld.

Another common form of welding uses gas. Many types of gas can be used, but a common example is an acetylene and oxygen torch. The welder uses a hot flame from the torch to join metal edges. When the edges are melted, the welder melts a rod into the joint. The rod supplies the extra metal needed to make the weld. The size of the flame and type of welding rod can be adjusted according to the particular job.

Job Description for: "Welder-Fitter"

2009-11-09T18:27:00.001-08:00

Use hand welding and flame-cutting equipment to weld together metal components and parts or to cut, trim, or scarf metal objects to dimensions, as specified by layouts, work orders, or blueprints.

Lays out, positions, and secures parts and assemblies according to specifications, using straightedge, combination square, calipers, and ruler.

Tack-welds or welds components and assemblies, using electric, gas, arc, or other welding equipment.

Cuts workpiece, using powered saws, hand shears, or chipping knife.

Melts lead bar, wire, or scrap to add lead to joint or to extrude melted scrap into reusable form.

Installs or repairs equipment, such as lead pipes, valves, floors, and tank linings.

Observes tests on welded surfaces, such as hydrostatic, x-ray, and dimension tolerance to evaluate weld quality and conformance to specifications.

Inspects grooves, angles, or gap allowances, using micrometer, caliper, and precision measuring instruments.

Removes rough spots from workpiece, using portable grinder, hand file, or scraper.

Welds components in flat, vertical, or overhead positions.

Heats, forms, and dresses metal parts, using hand tools, torch, or arc welding equipment.

Ignites torch and adjusts valves, amperage, or voltage to obtain desired flame or arc.

Analyzes engineering drawings and specifications to plan layout, assembly, and welding operations.

Develops templates and other work aids to hold and align parts.

Determines required equipment and welding method, applying knowledge of metallurgy, geometry, and welding techniques.

welders demands abroad

Definition and Nature of the Work

Job Description for: "Welder-Fitter"