15th January 2018 Blog
THE BASICS OF SHEET METAL FABRICATION
Sheet metal fabrication involves a broad range of processes that can often be confused. As a result, we’ve created a beginner’s guide to sheet metal fabrication and the processes that are involved.
In the broadest sense, sheet metal fabrication is the creation of metal structures by using a variety of processes. Most often sheets of steel or other metal materials are processed and assembled to create a larger final product. In order to bind these smaller components, processes such as welding are used to provide a high-quality finish that create a range of products of varying shapes and sizes.
The stages of sheet metal fabrication
Each project is different but are primarily constructed using four key phases.
Although different companies approach the design process in a variety of ways, here at Alpha Manufacturing, clients are offered the opportunity to provide design specifications at the beginning and work alongside our design and NPI (New Product Introduction) teams to tweak designs for manufacture. This is an integral part of the process and can determine the economic efficiency and best manufacturing approach of a project. Ensuring that a dedicated and experienced Designer, trained in CAD (computer aided design), is present at this phase is vital to creating a high specification final product.
Once the design has been formalised, these designs are translated into a language that is understood by the machinery that create the products – this is known as the programming process. Parts are drawn and then “nested” in 2D form onto a metal sheet, making sure that material utilisation is maximised.
Once the machine programs have been set to work, the laser cutting process takes place. As one of the most accurate ways of cutting sheet metal material, lasers follow the programmed design and cut through the material with ease and precision.
Many components require certain perforations or forms such as ribs, louvres or countersinks. For this, a CNC punching machine uses specific tools to “hit” the metal sheet and either perforate or shape it in specific ways.
The bending process, known in the industry as CNC folding, is a practice that can be completed by a range of machines such as a manual press brake, an automated panel bending machine or robotic bend cell depending on the size and complexity of the part. Each machine forms the part by clamping the sheet metal between a top tool and die, applying pressure to obtain the intended curvature.
There are a range of welding techniques that can be done when working with sheet metal, this includes; MIG welding, TIG welding, spot welding, projection welding and robotic welding.
The assembly stage can vary depending on the complexity of the final product and can range from simple weld assemblies to complex electrical integrations including wiring looms, PAT testing and hardware installation. Some assemblies require insertion which is the process of pressing a stud, nuts or other components to fasten the product together.
The powder coating process is a process of applying and electrostatic powder to a charged metal component before curing at heat to produce a durable coating. At Alpha, we use an automated powder coating plant which uses a process of Oxsilan pre-treatment, drying, powder application and stoving.
Want to find out more about sheet metal fabrication? Take a look at our FAQs section for more details.