Sheet metal fabrication has undoubtedly become a vital part of the modern-day engineering industry. This process is used almost everywhere from simple workshops to mammoth-sized manufacturing plans.
In the 21st century, sheet metal plays a vital role in the engineering industry. If we look around, we can see it being used almost everywhere from cars, kitchen sinks, furniture, aeroplanes etc. Additionally, it plays a crucial role in the designing sector to test various designs and their effectiveness.
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What is sheet metal fabrication?
Sheet metal fabrication is a manufacturing technique in which flat and thin pieces of metals are transformed into shapes by using a variety of techniques such as cutting, stamping, punching and bending.
The design possibilities of sheet metal fabrication are almost infinite, which allows a broad range of products to be produced. The process is undertaken using special equipment such as chop saws, cutting torches, welding equipment etc.
Sheet Metal Fabrication Tools
This industrial process uses a special set of tools for forming, cutting and joining techniques to make sure that the metal gets into the desired shape.
Sheet metal fabrication involves a variety of tools depending on the specific purpose in hand.
However, after the revolution of CNC (Computer Numerically Controlled) technology, it became possible to perform almost all sheet metal operations with CNC.
These are computer-controlled machines that can mimic almost several cutting tools that are required for sheet metal fabrication. The designer will load the CAD file, which will be converted into a CNC file by the software program.
The machine fabricates as per the instruction fed into its central computer.
CNC machines have gained enormous popularity for their precision and reducing the labour cost.
Some of the most common tools used for sheet metal fabrication are
- Hole Cutters/Drillers: These are used to create holes on concrete substrates or metal alloys. Usually, the drillers will be equipped to cut holes of different sizes.
- Planishing Hammers: Planishing hammers are used to give gentle blows to the smooth metal that has already been formed by some other means.
- Multi-Press: As the name suggests, a multi-press features three machines in one. i.e. shoulder press, bench press and incline press. The users can adjust the seat and press arm for various requirements.
- Flange and Punch Tools: This is used to make clean and quick holes in the sheet metals. A variety of Punch and Flange tools are used for auto body repair and other fabrication methods.
- Corner Notcher for sheet metal: This is used for creating crisp corners. A sheet metal corner notcher is a machine that is designed to cut a 90-degree section with a V-shaped blade. The notcher is hydraulically powered and can form even minute cuts from 1mm up to 120mm in a single operation.
Bending tools, notchers, louvre tools are used for various bending purposes.
- English Wheels: These are used for light applications and heavy-duty constructions as well. One important feature of English wheels is that the quick release lower anvil wheels allows 90-degree rotation, beneficial for creating odd parts.
Types of sheet metal fabrications
Sheet metal fabrication techniques are broadly classified into three:
1. Cutting
In a broader sense, CNC cutting can be classified into two, i.e. cutting with shear and cutting without shear.
The process of cutting without shear is used for non-industrial products which require better precision, while sheer cutting is used for industrial products.
Sheer cutting includes processes such as cutting, blanking and shearing.
- Cutting: Removing one specific portion of the metal by using a blade
- Shearing: This is a more advanced form of cutting. Here a large portion of metal is cut out from a continuous sheet. This action is somewhat similar to that of scissors in which the lower blade remains fixed while the movable upper blade performs the cut.
- Blanking: In this process, a metal workpiece will be removed from a primary metal strip when it is punched.
- Non-sheer cutting: This is done to get accurate dimensions. The process is usually done for specific industry products such as computer parts, aeroplane wings etc.
- Laser cutting: This process is very accurate and uses a very high beam laser to cut through the metal.
- Plasma cutting: This process involves the use of compressed gases such as hydrogen and nitrogen to produce a high beam plasma laser for cutting purpose.
- Water jet cutting: This process used high speed and pressurised water mixed with abrasives to cut through metals.
- Machining: This includes processes like spinning and milling, where a lathe blade or drill bit is used to cut off pieces of material.
2. Forming
The process of forming is used in manufacturing industries where the material undergoes plastic deformation to acquire different size and shape for various purposes.
Unlike cutting, in this process, no metal is removed but displaced or deformed to get the desired shape.
- Bending: Usually done by hand or press brakes.
- Stretching: The metal is pulled apart by using a dolly, hammer or English wheel.
- Roll forming: This process has a similar effect to that of bending. In roll-forming, a continuous sheet of metal is rolled to achieve the desired shape. The rolling is made possible with the help of mechanical rollers.
- Stamping: In this process, a flat sheet of metal either in the form of a blank or coil is placed into a stamping press. Within the press, a tool or die forces itself into the metal to form the desired shape. Punching, blanking, bending, coining are examples of stamping techniques.
3. Joining
In this method, two different metal pieces are joined together using a variety of techniques as mentioned below:
- Welding: In this process, two pieces of metals are joined together by using high heat to melt the parts together and join them. This is quite distinct from other joining techniques such as brazing and soldering, where the base metal does not melt.
- Brazing: Here, joining is done by a metal filler rather than melting the two metals.
- Riveting: Here, small metal parts are joined by embedding them through sheets.
- Adhesive: Metal sheets are joined together either alone or by using another joining method.
Advantages of sheet metal fabrication
Following are some notable advantages that the process offers:
- Highly resistant to corrosion from the intense heat of the sun, moisture and other harmful chemicals. The process is ideal in today’s environment when the metals are exposed to toxic chemicals present in the atmosphere.
- High strength and long-lasting.
- Less weight: Sheet metals are easy to carry around.
- Durability: The sheet metals are strong and could withstand high pressures.
- Malleability: The metals can be transformed into almost any shape. This technique gives limitless capability while constructing structures and buildings.
- Recyclable: The sheet metals can easily be recycled after use and leaves a very less carbon footprint.
- Widespread availability.
- Cost-effective: The widespread availability of high-quality sheet metals and metal fabrication helps the firms, manufacturing firms and contractors to save a lot of costs, helping to reduce the overall cost of construction.
- The idea of architects and designers can be quickly materialised through sheet metal fabrication technology.
- Easy to repair: One prime advantage of using sheet metal is that repair workers can quickly inspect the damage and fix it without having much effort. The unique feature of sheet metal is that the damaged part can be removed and replaced without taking down the entire structure.
- High quality of construction: because of its durability maintaining sheet metals are easy and difficult like using other materials.
Application of sheet metal fabrication in various industries
This process is very flexible and can be used in factories for creating individual components to automotive bodies.
Sheet metal fabrication is used in a variety of industries such as consumer goods, robotics, electronics, energy sector, automotive, shipbuilding, construction and aerospace.
You might be wondering about the sheer expansiveness of the list of sectors where this is used. This is simply because sheet metal fabrication is an unavoidable element of all industries.
This technique is easier to implement when compared to other manufacturing techniques such as additive manufacturing, die casting etc.
Some of the applications of sheet metal fabrications include:
1. Hot rolled steel
This is roll pressed at high temperature (over 1,700ËF) which is way beyond the recrystallisation temperature for most steels. The process makes the steel easier to form and produces products that are easier to work with.
After rolling the temperature will go down; as a result, the metal cools down and shrinks. Thicker plates can be easily produced by this method.
2. Cold-rolled steel
Here roll pressing is done at lower room temperature. Cold-rolled steel can have a smooth surface, but the thickness is limited to 3mm.
This is used in applications that require a smooth surface. Some of the examples include lockers, cabinets, furniture etc.
3. Stainless steel sheets
They are excellent in environments prone to corrosion. Some of the equipment made out of this process include sinks, kitchen accessories, cutlery, medical apparatus, surgical equipment etc.
At an industrial level, sheet metals are used to make valves, piping, storage tanks, joints etc.
4. Aluminium sheets
The great thing about aluminium sheets is that they are lightweight, robust and corrosion-resistant. However, when compared to other metals, aluminium is costly, which is why you can’t find it’s application everywhere.
Aluminium is most commonly used in the transportation industry due to its lightweight nature and long-lasting capability.
Some of the consumer goods that are made out of aluminium casings include laptops, phones etc.
Final Words
Sheet metal fabrication finds its rightful place in almost all industrial sectors. With the right kind of technology, you will be able to manufacture products out of sheet metals with accurate dimensions.
In this article, we have shared information on materials, tools and techniques of sheet metal fabrication.
By employing computer-controlled CNC machinery, it is possible to automate and fabricate the sheet metals without having to go through a multitude of individual manual steps like welding, bending, cutting etc.
