From construction and aerospace to automotive and consumer goods, sheet metal fabrication is fundamental to the modern world. It is where high-tech processes meet skills that are thousands of years old. In this guide, we’re looking at the basics of sheet metal fabrication in what is a diverse industry. We’ll cover the various processes and materials, and the benefits and drawbacks of fabricating from sheet metal.
Fabrication of sheet metal is the process of transforming flat sheets of steel, aluminium or other metals into finished metal products through cutting, punching, folding and assembling. Pretty much any shape can be created though these processes, the result being tough, rigid components or end products.
The roots of metal fabrication can be traced back to ancient civilisations, although reliable means of making sheet metal (chiefly rolling) came about as recently as the 18th century. In modern times, sheet metal fabrication uses sophisticated equipment and computer-aided design software to produce high-quality, accurate and durable metal products.
The sheet metal fabrication process
Almost any metal form and finish imaginable can be achieved through a relatively small number of distinct processes.
Cutting
Cutting is typically the first step in transforming sheet metal into a workable piece. Laser cutting is the preferred method for speed and precision, although mechanical cutting methods such as shearing and punching are also used depending on the material and design requirements.
Bending and forming
Metal bending and forming processes alter the shape of the metal without reducing its mass. Techniques like CNC folding and manual press braking apply pressure to create bends and curves, essential for achieving the final product’s shape and functionality.
Welding techniques
Most finished products require more than one distinct piece of metal to complete them. Welding assembles the components into a cohesive structure. Various welding techniques, such as MIG, TIG and spot welding, are employed based on the material type and the specific requirements of the product. Welding fabricators create a homogeneous piece of metal with optimum strength as it involves melting the metal pieces at their joins, so they cool into a single piece.
Finishing process
The finishing process enhances the product’s durability, weatherproofing and aesthetic appeal. Finishing methods such as sandblasting, priming, wet painting, polishing and powder coating services add protective layers and create more attractive surfaces. However, the main purpose is to make the metal more resistant to corrosion and wear.
Types of sheet metal and their applications
All metals are not created equal. Each comes with its own properties that influence its use in the real world. For example, cost, flexibility, weight, corrosiveness and strength all feed into the decision. Also, not all metals are used in their purest elemental form – alloys are where two or more materials are added to a metal to enhance its properties. Steel, bronze and brass are all alloys, and the blends determine their properties and cost.
Aluminium: the featherweight champion
Aluminium is often the go-to material when a decent strength-to-weight ratio is required. It’s lightweight yet durable, making it ideal for automotive parts and aircraft components. It’s also highly resistant to corrosion and has excellent conductivity, making it a versatile material. You’ll also find it in cooking vessels like pans, owing to its ability to evenly distribute heat.
Aluminised steel: the hybrid wonder
Aluminised steel combines the best of both worlds: steel’s strength and aluminium’s corrosion resistance. This material is perfect for high-temperature environments, such as kitchen appliances and exhaust systems. The aluminising process, which involves hot-dipping steel in aluminium, gives a rugged layer of protection.
Carbon steel: the industrial workhorse
Carbon steel, with its remarkable hardness and strength, has been a staple of industry and weaponry for centuries. It’s essentially iron infused with carbon, and is capable of undergoing heat treatment to further enhance its properties. It’s commonly used in the construction of bridges, buildings and countless other objects.
Copper: conductivity and beauty
Copper is known for its electrical and thermal conductivity, making it an obvious choice for electrical wiring, motors and transformers. But it also has aesthetic appeal and malleability that make it popular in architectural applications, such as roofing and gutters, as well as in home fixtures. However, it’s worth noting that copper comes at a heftier price tag compared to aluminium.
Galvanised steel: where rust-resistance it vital
Galvanised steel is steel that’s been coated in a layer of zinc to prevent rusting. This zinc coating significantly extends the lifespan of steel, making it a cost-effective solution for long-term projects. It’s a staple in environments where moisture and corrosion could jeopardise normal steel, and is therefore common in water pipes, roofing and fencing.
High-strength steel: heavy duty performance
Used extensively in military applications, high-strength steel offers unparalleled durability. It is alloyed with elements like carbon, manganese and copper to enhance its hardness and wear resistance. Armour plating is a prime example, but you’ll also find high-strength steel in heavy-duty machinery and automotive components that require extra resilience.
Stainless steel: the knives are out
Stainless steel is a marvel of modern metallurgy, arriving as recently as the early 20th century. As it provides excellent resistance to corrosion, heat and fire, it’s used for kitchenware, medical equipment and food processing machinery. It’s also beautiful to look at, with its clean, reflective, silvery appearance, making it an excellent choice for cutlery.
Titanium: lightness and strength, at a price
Titanium is valued for its high strength-to-weight ratio and superb corrosion resistance. These qualities make it indispensable in the aerospace industry, where it’s used for aircraft components that require both strength and lightness. In its basic form it’s double the price of aluminium, but if high-grade titanium is required, the price can be an order of magnitude higher.
Applications of sheet metal fabrication across industries
Sheet metal fabrication shapes metals into versatile, durable components that find their place in all sorts of industries. Here are some of the key sectors that benefit from sheet metal fabrication.
- Construction and security: Sheet metal is a key component of roofing, cladding and fencing. Its strength and durability make it perfect for the sector, while the low cost of certain materials like galvanised steel mean it can be used in large quantities, cost-effectively.
- Transportation: From the bodywork of cars, vans and trains to pressurised aerospace fuselages, sheet metal has long been vital for transportation.
- Science, medical and food industries: sheet metal storage units and worktops are ubiquitous in food preparation, as well as in countless medical and scientific applications. Chemical resistance and ease of cleaning are key benefits that metals like stainless steel bring to the table.
- Kiosks and vending machines: These items are often used by the public so need to keep their integrity over years of use. Sheet metal is the perfect material to keep them secure, functional and looking good.
- Domestic appliances: From washing machines and toasters to lamps and entertainment equipment, the world of domestic devices would look very different without worked sheet metal.
Benefits of sheet metal fabrication
Sheet metal fabrication comes with a host of benefits that make it an invaluable process across numerous industries. Here’s why it’s so important.
Strength and durability
Metals like steel, aluminium and titanium are robust, making them ideal for applications that demand long-term performance. Whether it’s structural components in construction or intricate parts in aerospace, products made using sheet metal can withstand years of wear and tear.
Versatility
Sheet metal working can be used in a wide range of projects, from small electronic components to huge architectural structures. This versatility is particularly valuable in industries like automotive, where diverse materials are needed for different parts of a vehicle.
Ease of maintenance
Metal products fabricated from sheet metal are less susceptible to rust or corrosion, often when treated with appropriate finishing techniques like powder coating, galvanising or anodising. Additionally, these metal products are resistant to fire and heat, further enhancing their longevity and reliability.
Cost-effectiveness
High-quality materials and machinery used for sheet metal fabrication are cost-effective in the long run. The durability means less frequent replacements and repairs, which translates to lower maintenance costs.
Aesthetic and functional flexibility
The ability to make sheet metal into nearly any shape is essential for both aesthetic and functional purposes. It allows designers and engineers to create products that are visually appealing while also being strong.
Drawbacks of sheet metal fabrication
While sheet metal fabrication offers numerous benefits, it also comes with its set of challenges and considerations that must be expertly managed to ensure successful outcomes.
Technical complexity
The technical complexity of sheet metal fabrication can be daunting, especially when dealing with intricate, high-precision bends, curves and assemblies.
Material selection
Each metal comes with its own set of properties that make it suitable for specific applications. Engineers need to find the balance between cost, weight, fatigue resistance and other properties, and there are dozens of metals to choose from.
Precision
Sheet metal can be rather flexible, especially in large sheets. That can pose certain engineering challenges when rigidity and expansion resistance are needed within small size tolerances.
Limited applications
Sheet metal isn’t appropriate for all metal applications. It will never replace casting and forging in certain engineering and aesthetic applications.
Tools used in sheet metal fabrication
To give an idea of the sheer number of tools out there, here’s a quick list of some of the tools that are used to fabricate items from sheet metal.
Cutting Tools
- Laser cutters
- Plasma cutters
- Mechanical shears
- Saws
- Drills
Forming tools
- Press brakes
- Folding machines
- Roll Forming machines
Punching tools
- CNC Punch Presses
- Manual Punches
Welding tools
- MIG (metal inert gas) welders
- TIG (tungsten inert gas) welders
- Spot welders
- Robotic welders
Finishing tools
- Sandblasters
- Grinders and polishers
- Powder coating equipment
Sheet metal fabrication specialists
With all this equipment, operational know-how and technical understanding, there’s no mystery why many manufacturers outsource their sheet metal fabrication to specialists. It’s useful if only a small part of a larger product is made of sheet metal and it wouldn’t be economically justifiable to invest in the extensive machinery and training required. Whether it’s high-precision work or mass-produced parts with large tolerances, having a professional sheet metal fabrication company as a supplier & partner makes a lot of sense.
