There are many different facets to sheet metal shaping, a variety of techniques can be used to create the desired shape depending on the type of metal used and the desired product. At Customised Sheet Metal we have more than 30+ years of experience honing these skills and creating beautiful, bespoke pieces in a huge range of industries.
In this guide we will take you through the most popular sheet metal techniques, their advantages and disadvantages and what kinds of effects and projects they can be used to create.
Cutting
How many ways are there to cut a piece of metal? More than you might think! In days gone by all metal cutting would have been done by a specialised saw. While effective enough, this can sometimes leave rough or imperfect edges.
Luckily, these days there are a number of cutting techniques that can work the metal into the desired shape. Laser cutting and plasma torches are used when precision is of the utmost importance, while high-powered water jets can also be used. The technique used will depend on the finish required and the project budget.
Rolling
In this process, sheet metal is passed through two carefully calibrated rolls, in order to reduce the thickness of the metal and to make sure its thickness is uniform. This process is repeated until the metal achieves the desired thickness.
This process is most commonly used when the desired outcome is a smooth curved surface to the metal. Cylinders, cones and rounded architectural features are all made using roll forming techniques. The process involves passing the metal through a series of rolls. Each roll bends the metal a tiny bit more, until the desired width and curvature has been achieved.
Hot rolling
This method of rolling involves heating the metal above its recrystallization temperature, and steel is the most commonly used metal for this process. Hot rolling improves many aspects of the metal including making it tougher and more durable, as well as making it easier to weld afterwards.
Cold rolling
Unlike hot rolling, cold rolling is a technique that is performed at room temperature and relies on mechanical force rather than temperature to change the shape of the metal. Like hot rolling, steel is the most commonly used metal although other metals such as titanium and aluminium can also be cold rolled. The benefits of cold rolling are creating a very smooth surface and increasing the strength of the metal.
Bending
Simply put, bending is the process of applying force to sheet metal to form the desired shape. Bending is used for a variety of reasons in the sheet metal industry, including creating the desired shape, reducing sharp edges and sometimes merely for cosmetic reasons.
There are multiple types of bending methods, many involve using a tool called a punch and die set. Expert metalworkers like our team at Customised Sheet Metal can advise on the most appropriate bending technique depending on the needs of the project.
Air bending
Air bending got its name from the fact that only part of the material comes into contact with the punch tool to achieve the desired shape. The further the punch pushes down, the narrower the angle of the bend. This technique requires less force than other types of bending, which can also be used to create a wide variety of angles with just the one tool.
Bottom bending
This also involves using the punch and die set, but the material comes into contact on three sides of the punch and die set. Bottom bending requires more force than air bending but produces more accurate angles. Unlike air bending however, it requires multiple unique tools for each different angle bend.
Coining
This technique gets its name from its original use – manufacturing coins. The punch tip uses so much force that it penetrates the metal under extremely high amounts of pressure, which relieves the internal stress on the metal and therefore reduces the possibility of spring-back. A drawback to coining is that it requires much more tonnage (punching force) than other types and is harder on the machinery causing more wear and tear.
In general, bending is a cost-effective method for shaping sheet metal into the design that you require. The most common bending technique is to use a press brake. This forces the metal between a knife edge top tool and a vee-shaped bottom tool to shape the material to the required angle over lengths up to 10 metres long.
Welding
Welding is a technique that uses electricity to join separate pieces of metal together to form one single piece. It is a process that takes many years of practice to master, and it’s something the team at Customised Sheet Metal have perfected after 30+ years in the industry.
There are four main types of welding: Metal Inert Gas (MIG), Metal Active Gas (MAG) welding, Tungsten Inert Gas (TIG), and gas welding and brazing. The type used will be dependent on the type of metal and the needs of the project, but we can weld a multitude of different metals, different thicknesses across a range of sectors. Our specialist welding services extend to being able to weld aluminium, copper, brass, zinc, and tantalum.
How to fold sheet metal?
There are multiple ways in which you can fold or bend sheet metal. The main element when it comes to how to fold sheet metal is that you need force that exceeds the material’s strength. This is the only way that metal will fold.
This can either be done by hand, using heat to soften the material before folding, or more commonly, by using a press brake. A press brake works by lowering a punch (also called a knife) onto the sheet metal that has been carefully positioned.
The metal may be bent several times to achieve the desired shape.
Press brakes are hugely versatile machines because they can be used for sheet metal folding for nearly any product. Whether you need a small bracket or large industrial machine, using a press brake is the best effective way to fold your metal
What is the purpose of folding in sheet metal work?
The purpose of folding your sheet metal is to create the perfect bespoke product that you need. By folding your sheet metal, you are forming it into the shape that forms your end product. Without sheet metal folding, your product would never take the right shape.
What is the sheet metal folding process?
Now you know how to fold sheet metal, let’s go through the sheet metal folding process in more detail.
Sheet metal folding is a complex process and requires plenty of knowledge and experience to complete both safely and effectively.
The way sheet metal is folded is also dependent on the type of material you are folding. Depending on the complexity of the product, folding may not be the first process for the sheet metal.
Customised Sheet Metal adopts the most traditional and common method of folding which is to use the press brake machine. The design engineer will consider the material thickness, bend radius and batch size to select the most appropriate machine to use.
The press brake machine bends the sheet metal by clamping the metal sheet between a punch and a die, which are the top tool and the bottom tools. A pre-set program will have been determined and entered into the machine before feeding the sheet metal into the machine and applying the bend to the metal.
What is a bend radius in sheet metal?
As you were reading the sheet metal folding process above, you may have wondered what the term ‘bend radius’ means.
Bend radius refers to the inside radius of the bend, with this there are many factors to consider which will help you to achieve the correct bend radius in sheet metal.
Depending on the type of material used there will be a degree of ‘spring back’ which needs to be accounted for and in most cases, you will need to ‘over bend’ to achieve the correct internal radius after spring back.
Hopefully now you have more understanding about some of the different types of sheet metal shaping techniques used in the metal fabrication industry.
No matter the specifications of your product or project, we have the skills and experience in all aspects of sheet metal fabrication and we are well equipped to help bring your vision to life.