Steel fabrication is the process of cutting, bending, and shaping steel alloy to create a product. Unlike various types of welding in which items are repaired or strengthened, steel fabrication takes many pieces of metal and attaches them together in the form of a predefined shape and size.
This process requires a skilled technician who has experience in taking raw components and transforming them into marketable items, and there is often very little room for error. Industrial facilities use steel fabrication to create everything from vehicular parts to household appliances.
FABRICATING STEEL STRUCTURES
For steel structure, fabrication process is used to manufacture steelwork components that will, when assembled and joined, form a complete frame.
The frame generally uses readily available standard sections that are purchased from the steelmaker or steel stockholder, together with such items as PROTECTIVE COATINGS and BOLTS from other specialist suppliers.
Although a wide range of section shapes and sizes are produced, the designer may find that the required section size is not available. In this case, built-up girders may be fabricated from plate. Sections and plate girders may also be strengthened by stiffening the web or flanges depending upon the load to be carried.
CAD, CAM AND CNC
Most modern steelwork fabrication factories have computer aided design and detailing (CAD) which is linked directly to factory floor computer numerically controlled (CNC) machinery creating a genuine CAD/CAM environment.
The accuracy of the computer generated details being transmitted directly to the computer aided manufacturing (CAM) machinery increases the quality standards of production
The fact that machinery has taken over from the tape measure means that the frame is produced to high quality standards which are reflected in the speed and accuracy of steel erection on site. This results in significant benefits both to the client and main contractor.
MATERIALS AND COMPONENTS
Steel sections and plate, structural bolts, welding consumables, light gauge decking and corrosion protection and fire protection systems are all manufactured to British standards (issued as BS EN).
In addition to these materials, steel fabrication also needs fabrication equipment (e.g. cutting, sawing, drilling, welding machines etc.) and software (e.g. for computer controlled machinery).
SECTIONS AND PLATES
Steel sections and plates are generally manufactured to BS EN 10025-2 for open sections, BS EN 10210-1 for hot-finished tubes, and BS EN 10219-1 for cold-formed hollow sections.
Large orders can be supplied direct from the steel mills, but Steelwork Contractors normally obtain their steel sections and plates from a steel stockholder. Steel stockholders play a vital part in the steel construction supply chain, ensuring that the market is supplied with what it needs when it is needed.
The industry has an extensive network of depots serving all parts of the country. The stockholders provide a range of products to the construction industry including heavy structural sections, plates, light sections, cladding materials, flats, angles.
Structural bolts are manufactured to British standards – BS EN 14399 for preloaded bolts and BS EN 15048-1 for non-preloaded bolts.
The exacting quality control requirements placed on manufacturers and distributors ensures the quality of structural bolts placed on the market.
Proprietary products such as some cellular beams, fasteners, purlins, cladding and roofing systems are also available and can provide novel and cost effective alternative solutions.
DESIGN FOR ECONOMIC FABRICATION
There are a number of general "technical" factors to consider in terms of design for economic fabrication that apply to most building projects. Some relate to the complexity of the particular project, whilst others are specific to the type of project, e.g. multi-storey, portals, trusses.