What is Sheet Metal Fabrication?

Sheet metal fabrication is vital for many industries, from construction to aerospace, automotive, and beyond. It’s a refined manufacturing process that is responsible for a great number of products that you see every day.

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Metal fabrication has been around for centuries, but it continues to evolve with technological advancements. From creating precision parts for machinery to metal structures for buildings and bridges, its use cases are in even more areas than you’d think.

In this guide, we’ll cover:

• What sheet metal fabrication is
• How the process works
• Different types of sheet metal & the applications
• Benefits of sheet metal fabrication

So, let’s explore and, as always, if you have questions or are interested in what we do, we at Salamander have over 50 years’ experience in sheet metal fabrication services to support your next project.

What Exactly Is Sheet Metal Fabrication?

Sheet metal fabrication is the process of turning flat sheets of steel or aluminium into metal structures or products, by cutting, punching, folding and assembling. Sheet metal can be cut, bent or stretched into nearly any shape, which is generally done by cutting and burning the metal.

Special tools, such as band saws and chops saws, can also be used in the sheet metal fabrication process. These ensure even cutting throughout the process. Cutting torches are capable of cutting large sections of sheet metal with minimal effort.

Sheet metal fabrications use press brakes, which ease the process of sheet metal fabrication, by helping to create sharp bends and angles within the metal. There are a variety of different press brakes, which have different functions and are used for different purposes.

One of the other main factors in sheet metal fabrication is welding. Once all the components are formed, they are then assembled and tack welded into position. Many welding techniques can be used in sheet metal fabrication in order to prevent warping or any other abnormalities. These techniques include covering the metal with sand during the cooling process, special straightening process, welding in a staggered manner and using a stout fixture.

Straightening defected metal can be achieved by using with an oxy-acetylene torch. Heat is applied to the metal in a slow manner to remove any abnormalities.

The metal is usually finished by being sandblasted, primed and painted. This then ensures the metal looks fantastic and then is ready to be sent to the client.

If you have an upcoming project or want more details about we can do for you, don’t hesitate to get in touch. 

How the Sheet Metal Fabrication Process Works

Metal fabrication tends to start from processing raw materials, which are often large and thick – for example, steel, aluminium and copper. Sheet metal can be cut, bent or stretched into most desired shapes.

Here are the typical steps for how it works:

Design

The design stage is where the groundwork for the project is laid out. Designers will usually create initial sketches or 2D/3D models of the product, which may be done using computer-aided design (CAD) software or by hand. 

Important factors such as the intended use of the product, the required dimensions and tolerances, and any specific materials or finishes that will be needed are mapped out before the manufacturing begins. 

Cutting

Laser cutting is typically the first step in the manufacturing process. Laser cutting is one of the most precise ways of cutting sheet metal as the lasers are able to follow the programmed design and cut through the material accurately. 

Bending

The bending process is known as CNC folding and is a practice that can be completed using a variety of machines. For example, a manual press brake or automated panel bending machine. 

The machine forms the metal part by clamping the sheet metal and applying pressure to maintain the desired curvature.

Forming

The forming process bends or deforms the material into the required shape. Different from cutting, which subtracts the material, forming actually reshapes the material without decreasing any of its mass. 

Welding

There are a variety of welding techniques that can be used when working with sheet metal, including MIG welding, TIG welding, robotic MIG welding and spot welding. 

• Metal inert gas (MIG) welding: A typically fast welding option that is better for thicker materials.
• Tungsten inert gas (TIG) welding: Offers greater control and precision than MIG. Best for thinner materials. You may also see it referred to as gas tungsten arc welding (GTAW).
• Robotic MIG welding: This is an automated version of more traditional MIG welding.
• Spot welding: This follows an electrical resistance welding process.

Finishing

Finishing is the last step when preparing metal products for use and makes products more resistant to corrosion, adding another layer of durability. It also helps make the surfaces look appealing.

Common finishing touches could include surface preparation, polishing and powder coating in a choice of colours, anodising, passivation, and laser marking (such as logos or etching some text).

Assembly 

In a sheet metal fabrication project, assembly refers to the assembling of the required products before they are packaged and delivered to where they need to be. 

At Salamander, we can act as a subcontractor to provide individual parts or carry out full-service electro mechanical assembly to bring you a complete ‘end product’.

Major Types of Sheet Metal

• Aluminium: Used for automotive parts, electrical devices, and cooking vessels. Offering numerous benefits including a good strength-to-weight ratio, and high conductivity. 
• Aluminised steel: This metal combines the high strength of carbon steel with aluminium’s superior corrosion resistance. Sheets of aluminised steel are used for products intended for high-temperature environments, such as kitchen appliances.
• Carbon steel: Carbon steel is used in the industrial and consumer markets for a range of products. It is a steel alloy that contains carbon, resulting in the material increasing in hardness and strength when it undergoes heat treatment. 
• Copper: Examples of products made from copper are sinks, roofs, rain gutters, and doors. Copper features higher electrical and thermal conductivity in comparison to aluminium but can be more expensive. 
• Galvanised steel: Sheets of galvanised steel tend to be used for making automobile bodies, water pipes, fences, roofs, and staircases. It is made by coating steel with zinc through a hot dipping process, helping to make it more corrosion-resistant. 
• High-strength steel: Military armour plates tend to be made from sheets of high-strength steel. The material is produced by alloying steel with a range of elements such as carbon, manganese, and copper. This helps to improve its hardness.
• Stainless steel: Used for kitchen vessels, storage tanks for chemicals and food processing machinery. Stainless steel offers superior corrosion resistance, fire and heat resistance, strength-to-weight ratio, and manufacturability. 
• Titanium: Typical products made from titanium include aviation parts, medical equipment, and construction elements. It is primarily used for its high strength-to-weight ratio and corrosion resistance. It is also recyclable. 

Applications of Sheet Metal Fabrication

Whether for structural purposes, decorative elements, or functional components within other products, many different industries rely on sheet metal fabrication. 

Let’s take a closer look at its variety of common use cases.

Kiosks, vending machines & enclosures

Vending machines and kiosks bring in significant revenue for many customer-facing companies – for example, gyms and leisure centres. This is why care needs to be taken in their construction. 

There are a large number of individual components needed to go into building these types of machines, which is why they require the application of sheet metal fabrication. 

Construction & Security 

The construction and security sectors use the application of sheet metal fabrication for products such as security doors, guard rails, security grills and bespoke security enclosures. 

Retail 

Creating appealing visual merchandise, as well as product displays, in the retail sector requires sheet metal fabrication. 

Sheet metal fabrication can help create a wide range of retail display units for different retail clients, retail spaces and shop displays. For example, bar displays, retail display cubes, portable displays and point-of-sale stands. These products need to be eye-catching and highly functional.

Science, medical & food 

Particularly the scientific, medical and food industries utilise sheet metal fabrication to create products found in commercial and industrial kitchens such as worktop surfaces, storage units, and sinks. 

Stainless steel tends to be the material of choice for many applications in the food production and preparation industries. 

Transportation

The transportation sector uses thousands of different products made using metal fabrication. For example, emergency vehicles rely on sheet metal fabrication for the construction of products such as glove-box enclosures, side steps, door-handle mounts, and steel surrounds for tail-lift doors. 

Sheet metal fabrication is an excellent method for creating parts both large and small that can go into vehicle construction. On top of that, safety rails on building sites, ladder hatch trap doors, and stair-safe products are constructed through sheet metal fabrication. 

Benefits of Metal Fabrication

Sheet metal fabrication offers many benefits, but the three main benefits are:

• Strong & Durable: When looked after well, metal fabrications can last many years without needing to be replaced, making them great for projects that require long-term durability.
• Versatile: It can be used for a wide range of different-sized projects, making them a valuable asset for many businesses as well as for individuals.
• Easily maintained: Metal fabrications are not susceptible to rust or corrosion and are resistant to fire and heat, making the process great for industrial and commercial settings.

The Go-To Choice for Sheet Metal Fabrication

We are a full-service sheet metal fabrication company that works with organisations all over the country to create high-quality fabricated metal products with an exceptional customer experience. 

We pride ourselves on our ability to offer both end-to-end sheet metal fabrication and sub-contracting services. We have been the UK’s chosen choice for sheet metal fabrication solutions for over 50 years, and our plan is to keep it that way with guaranteed quality every time!

Cutting is usually the first phase in the sheet metal fabrication process. You can cut different shapes or structures from rectangular metal sheets to meet design requirements. The main cutting techniques involved two categories: cutting without shear and with shear.

1. Cutting Without Shear

There are several processes that enable adequate cutting through sheet metal material without shear force. These techniques involve extreme heat, high pressure, vaporization, and abrasive blasting to shape the sheet metal fabrication parts. They include the following:

1.1 Laser Cutting

Sheet metal laser cutting involves using focused laser beams to melt metals in localized areas. Laser cutters are compatible with a long list of metals, ranging from non-ferrous metals to mild steel and stainless steel.

This technique consists of two concurrently running sub-processes. The first one involves concentrating a high-powered laser beam on the sheet metal. The material absorbs the laser beam’s thermal energy, making it vaporize.

At the same time, the second process involves a cutting nozzle providing blowing gas for laser cutting. This gas is usually oxygen or nitrogen. It helps to prevent the processing head from splashes and vapors during sheet metal fabricating engineering.

1.2 Plasma Cutting

Plasma cutting is a thermal cutting process involving metal with ionized gas called plasma. The method uses substantial heat to cut the metal, which creates large burrs and an oxidized zone close to the cut area. In addition, it allows faster cutting, high precision, and repeatability in sheet metal manufacturing.

The plasma cutting tool works effectively only on electrically conductive sheet metals. Consequently, it is one of the most suitable methods for cutting conductive materials with medium aluminum thickness.

1.3 Waterjet Cutting

This cutting process involves using a high-pressure stream of water to cut metal sheets. Waterjet cutting is versatile and can cut various hard and soft materials using pressurized water and abrasive. It is ideal for cutting soft materials, metal foils, fabrics, or rubber. At the same time, it is suitable for cutting hard materials like copper, carbon steel, aluminum, and carbon steel.

The pressure involved is usually about 60,000 psi, with a 610m/s supply of velocity to cut through different types of metal sheets. However, waterjet cutting is a better substitute for the laser cutting technique.

2. Cutting With Shear

The processes under this category cut metal materials using shearing force to overcome the metal’s ultimate shear strength. They usually involve using dies, punches, and shear presses to enable adequate cutting of the metal. The techniques here include the following:

2. 1 Shearing

Shearing is suitable for high-scale applications and cutting soft materials that don’t need clean finishes, like brass, aluminum, and mild steel. It cuts straight lines on sheet metals with a flat surface. The shearing method involves applying a shear force on the surface, causing the flat metal material to split at the cutting point.

This is often the ideal process for making straight edges on a metal sheet with rough edges. It is cost-effective for high-volume operations when manufacturing thousands of sheet metal fabrication parts within a short lead time. However, shearing may not be perfect for applications that need quality finishes due to the burrs and material deformations it causes.

2.2 Punching

Punching uses shear force to make holes in the sheet metal. In this sheet metal fabrication process, the scrap material is the material removed from the hole, while the final component is the remaining material on the die.

Punching is suitable for making cutouts and holes of different shapes and sizes. However, using the punching process can take much time. You have to match the dies and punching knives correctly.

2.3 Blanking

Blanking is an ideal process for economic sheet metal fabrication. It involves removing a portion of sheet metal from a larger piece of the stock material using a blanking punch and die. The punch makes a “blanking force” through the sheet metal while the die holds it during the process.

The extracted material is the preferred component, while the remaining material on the die is the leftover black stock. This process is suitable for making economic custom parts due to its high repeatability, dimension control, and excellent accuracy.

2.4 Sawing

Sawing cuts metal materials using a sawtooth tool to create a series of tiny cuts in the metal. A sawtooth uses shear force and friction to tear apart a small part of the metal material. Band saws have various fine and marginally bent teeth suitable for cutting brass, aluminum, and other non-ferrous sheet metal.

Horizontal band saws help to cut longer bar stocks to desired sizes. On the other hand, vertical band saws help to achieve complex cuttings that need accurate contours in the metal parts.

The sheet metal forming techniques help reshape materials while maintaining their solid states. However, these techniques are different in their applications for creating custom sheet metal fabrication. This section will explain the essential forming techniques used in sheet metal engineering.

Bending

Sheet metal bending is highly cost-effective in low to medium-scale production. It involves deforming the metal’s surface with force and bending it at the required angle to create the preferred shape. You can use press brakes and a rolling machine to perform this operation. This technique is suitable for spring steel, copper, and aluminum .

Rolling

Rolling involves passing a metal piece through a pair of rollers to gradually reduce the thickness of the metal or get a balanced thickness. These rollers constantly rotate with high efficiency to form compressive forces. Consequently, the forces plastically alter the shape of the workpiece.

Cold rolling and hot rolling are the two major rolling processes. Cold rolling often occurs at room temperature, while hot rolling occurs at a temperature beyond the material’s re-crystallization. Discs, stampings, wheels rims, tubes, and pipes, are typical rolled sheet metal fabrication parts.

Stamping

Stamping combines complex cutting and forming processes with shorter sheet metal fabricating operations to achieve complex parts. Sheet metal stamping is a typical cold-forming technique that utilizes stamping presses and dies to shape raw materials into different shapes. It is compatible with many sheet metal materials – copper, aluminum, low- and high-carbon steel, and brass.

The metal stamping technique is often cost-effective, fast, and requires little tools and labor time. In addition, you can also automate the stamping process for high-quality precision parts and repeatability. However, it costs more to operate, and making changes to the design during production is challenging.

Hemming

Hemming is a custom sheet metal fabrication process that occurs when you roll over a sheet metal’s edge onto itself to form an area with two layers. It usually occurs in two different stages. Stage one includes blending the sheet metal and lowering it into a V-die. On the other hand, stage two involves the removal of the material and placing it into a flattening die. It helps to flatten the hem while giving it a preferred shape.

Hemming is often effective for strengthening parts’ edges and enhancing their appearance. The process has excellent accuracy that helps to create components with high-quality finishes. However, material deformation usually occurs during this process resulting in dimensional variations.

Curling

Curling is the process of joining round-like, hollow rolls to the edges of sheet metal. Its processes usually occur in three stages. The initial two stages form the curves for the curl, while the third one closes up the curl.

Curls effectively remove sharp untreated edges from a workpiece to make it safer for handling. Curling the edge gives it additional strength. However, curling can result in burrs and material deformation. As a result, the process needs the utmost care to get it right.