Metal fabrication is a process that supports a considerable number of industries that require metal components in different shapes and designs. Pre-fabricated components can be assembled on the construction site or in a metal fabrication shop that bids for a project based on engineering designs. Current processes of metal fabrication have significantly changed because of the introduction of CNC machines that handle most of the work that used to be done manually. Regardless however of the modernity of machines used in metal fabrication, it is essential for the client, designer, fabricator and contractor to interact with each other to attain efficiency and productivity for the success of the specific project. It is also a requirement for structural engineers to be acquainted with the different processes in metal fabrication as well as in all aspects of structural steel work.

The benefits of carrying out fabrication procedures in a metal fabrication shop

Fabrication procedures carried out in a metal fabrication shop are typically precise and accurate. The processes do not vary whether done onsite or offsite but metal fabrications shops tend to have more sophisticated equipment and machines including skilled fabricators who have gained years of experience in the various processes of cutting, bending and assembling. If the skill of the personnel onsite is inferior to that of the workforce in the metal fabrication shop, it follows that the end-product is less in quality and precision. In terms of cost effectiveness and adherence to delivery schedules, metal fabrication shops are considered more efficient. It is perhaps due to this advantages that industries prefer to send jobs to metal fabrication shops instead of hiring their own workforce for the job.

The sequence of operations in a metal fabrication shop

• Surface cleaning – blast cleaning is the accepted process of carrying out surface preparation in a well-run fabrication shop. Another method of surface cleaning is through the use of an oxy-acetylene torch or what is typically called as flame cleaning
• Cutting and machining –cutting to length is one of the initial processes that is carried out through sawing, chiseling or shearing. Hand –held devices like oxy-fuel torches or plasma torches are used in the absence of CNC cutters
• Punching and drilling – most metal fabrications shops have a range of machines to form holes for connections in the structural network. Traditional drilling machines are manually operated but this process has become too slow for a primary line production hence the CNC tools that drills in response to whatever data is keyed in.
• Bending – manually done by hammering or through press brakes to either coin or air-bend metal sheets into form.
• Assembly – joining the metal pieces together through welding, binding with adhesives, riveting or threaded fasteners. Welding is the most common practice to assemble components however; there is still demand for structural members to be bolted instead of welded.
• Surface treatment – in order to prevent corrosion, metal or paint coating is applied whether in the metal fabrication shop or in the construction site.