Sheet metal fabrication techniques & processes

Metal plays a key role in how we live and operate in every household and working environment across the globe. From light fixtures and appliances to utensils, furniture and cars, metal is the vital element that makes many modern conveniences possible. But how do the items we use every day actually get made? Well, sheet metal fabrication has a considerable role to play, as it’s the process of creating metal structures or parts from raw metal materials. Sheet metal fabrication can be complex and varied, and here Yorkshire Laser are going to explore the main techniques and processes involved.

The basics…

There are a number of sheet metal fabrication techniques such as punching, bending, cutting and welding that are used in the overall process of manufacturing metal products. Usually, large sheets of stainless steel, aluminium, copper or other metals are punched, bent or cut and then assembled to produce a larger final product. To fuse the smaller components together, various welding techniques are used to create products of varying shape and size, all with a high-quality finish.

The stages of sheet metal fabrication

Of course every sheet metal project is different, but most common sheet metal work will consist of the following key phases:

Design

Although sheet metal companies sometimes approach the design process in different ways, at Yorkshire Laser and Fabrication clients provide their own design specifications at the outset, and a specialist team will work alongside them to tweak the designs ahead of manufacturing. The design phase is integral to the sheet metal fabrication process and affects the best manufacturing approach to take, as well as the economic efficiency of a project. Using dedicated and experienced designers trained in computer-aided design (CAD) during this phase is essential to creating a high-spec final product.

Programming

Once the design has been agreed upon and formalised by both the client and the fabricator, the designs are translated into code that can be understood by the relevant fabrication machinery to create the products. This is referred to as the programming process. The required shapes of the parts are then drawn and ‘nested’ in 2D form onto metal sheeting of appropriate thickness, always ensuring that material utilisation is efficient and maximised.

Cutting

Once the programming process is complete, laser cutting can then take place. Modern laser cutters are one of the most accurate methods for cutting sheet metal material. They’re programmed with the relevant design and cut with precision and ease. Laser cutting has become a key part of the manufacturing process.

Punching

Large numbers of sheet metal components need perforations and forms such as countersinks, ribs or louvres. To achieve this, sheet metal fabricators use a computer numerically controlled (CNC) punching machine to ‘hit’ the metal sheet and shape or perforate it in precise, pre-programmed ways.

Bending

The process of sheet metal bending, also known as CNC folding, is handled by a range of dedicated machines including manual press brakes, automated panel bending machines and robotic press brake bending cells, depending on the complexity and size of the part. Each bending machine forms the required part by clamping a sheet of metal between a top tool and die, then applying pressure to create the pre-programmed curvature.

Welding

In order to fuse parts together there are a number of specialist welding techniques used when working with sheet metal. TIG welding, MIG welding, projection welding, spot welding and robotic welding are utilised in specific circumstances to permanently bond two surfaces or components.

Assembly

The last stage of sheet metal fabrication is of course assembly, which can vary in length and difficulty depending on the final product’s complexity. The process ranges from a simple weld, binding with adhesives or bending through to intricate electrical integrations, PAT testing, wiring looms and hardware installation. Some sheet metal assemblies also require insertion –  which involves pressing nuts or studs or to fasten the components together.

What tools and machines are used in sheet metal fabrication?

• A wide variety of tools are involved in the fabrication of sheet metals, including:
• Laser cutters
• CAD software
• Rapid prototyping machines
• Combination laser/punch machinery
• Folding machinery such as manual press brakes, automated panel benders and automated robotic folders
• Robotic welders
• CNC punch machinery
• CNC machine tools
• Precision turned parts machinery

An A-Z of sheet metal fabrication techniques

After looking at the processes involved, here’s a brief run-down on some more common sheet metal fabrication techniques that haven’t been mentioned so far:

Blanking

A technique in which parts are cut out of a sheet metal, and the remaining material around them is discarded.

Die cutting

Die cutting is used to cut sheet metal pieces without creating chips or the use of melting or burning. It’s also known as shearing.

Fastening

For products where the metal is too thin to be secured using other techniques, self-clinching fasteners such as studs, nuts, cable tie mounts, spacers or hooks are used to provide the required torque resistance.

Finishing

Finishing simply means when the surface of a completed sheet metal product is worked on and modified to achieve a specific property. This could include enhanced appearance; blemish removal; wettability or adhesion; anti-corrosion; solderability; wear resistance; electrical conductivity or surface friction control.

Galvanising

Steel or iron products are galvanised when they are dipped in zinc, which forms a protective coating that prevents rusting.

Milling

Milling is when fabricators use rotary cutters to extract material from a metal piece, advancing at an angle with the tool’s axis.

Oxyacetylene welding

A welding technique in which oxygen and acetylene contained in tanks are combined through an adjustable torch. The right mix gives a precise, controlled flame that is used to heat metal.

Roll forming

A continuous process of bending in which metal sheets, coils, bars or strips are fed through rollers in order to form the metal.

Stamping

Stamping – also known as pressing – is used for creating large quantities of products relatively quickly and involves placing sheet metal, in either blank or coil form, into a stamping press. The press uses a tool and die surface to form the metal into the shape required. 

Tungsten inert gas (TIG) welding

TIG welding is a two-handed arc welding process using non-consumable tungsten electrodes to produce clean, precise welds on more metals than any other comparable method.

Partnering with an expert sheet metal fabricator is critical to the success of your project. Yorkshire Laser and Fabrication prides itself on providing exceptional quality, exceptional service and exceptional value. Our team use the latest sheet metal fabrication techniques and are ready to discuss your next project. Give us a call on 01924 220236, email info@yorkshirelaser.co.uk or click here to get in touch.