Sheet Metal Fabrication 101: everything you need to know
Sheet metal fabrication is a process that involves the creation of objects from thin sheets of metal. It can involve everything from simple shapes to more complex designs. In this article, we will discuss what sheet metal fabrication is, and provide a guide on how to design and manufacture products using this process.
What is Sheet Metal Fabrication?
Sheet metal fabrication is a comprehensive working process for sheet metals (usually thinkness less than 10mm), including shearing, blanking, bending, welding, riveting, mold forming and surface treatment. Its remarkable feature is the same thickness of the same part.
The Process Of Sheet Metal Fabrication
First cut metal into flat sheets. These metal sheets are then formed into the desired shape using a variety of methods, such as stamping, bending, or welding. Finally, the object is finished by adding a coating or surface treatment.
Step1. Cutting Sheet Metal Materials
There are 5 method to cutting materials for sheet metal fabrication processes:
- Shearing:
it is use of shearing machine cutting sheet metals, it is mainly for mold blanking forming preparation processing, low cost, accuracy is less than 0.2mm, but can only be processed without holes without cutting Angle strip or block.
- Stamping：
It is the use of a punch in one step or more steps in the plate will be parts of the plate after blanking forming various shapes of materials and parts, its advantage is the cost of short hours, high efficiency, high precision, low cost, suitable for mass production, but to design the mold.
- CNC cutting:
CNC Flame Cutting and CNC Plasma Cutting are two main ways to cut metal in sheet metal fabrication, it is mainly used for complex graphics processing, small batch production.
- Water jet cutting:
It can be cut into any shape of the material. And no heat affected zone will be produced during the process of waterjet cutting, which is mainly used for processing materials that are not suitable for heat treatment.
- Laser cutting：
It is the use of laser cutting, in the large plate will be cut out of the structure of the plate shape, the same as NC material need to write laser program, it can be a variety of complex shape of the plate, the cost is high, the accuracy of 0.1mm.
- Sawing:
It mainly used cutting aluminum, square tube, drawing tube, round bar material, low cost, low precision.
Step 2. Punching & Broaching
Punching is a method of sheet metal fabrication that uses a punch to create holes or shapes in the metal. This can be done with a variety of different tools, such as an automatic punch, a hand punch, or a CNC machine.
There Are Three Types Of Punching:
- Blank punching:
It is to cut a circular or non-circular blank from a metal sheet with a punch.
- Die punching:
It is to cut a variety of shapes from a metal sheet with a die.
- Progressive die punching:
It is to cut multiple shapes from a metal sheet with a progressive die.
Broaching is in a small base hole into a slightly larger hole, and then tapping, The main use of thin plate metal processing, increase its strength and thread number, When the plate thickness is larger, such as 2.0mm, 2.5mm, etc., the metal plate can be directly tapped.
Step 3: Pressing Rivet
There are mainly riveting nuts, screws, loose, etc., which is completed by hydraulic riveting machine or punch, you need to pay attention to the orientation of the riveting nuts when riveting to sheet metal components.
Step 4: Sheet Metal Bending
Bend sheet metal is the folding of 2D flat pieces to 3D parts. Its processing needs to have a folding bed and the bending mold to complete, it has a certain bending order and steps.
In general, press riveting before bending, but some special sheet metal parts need to be reversed.
Sheet metal bending is the bending of sheet metal into the desired shape and Angle according to the requirements of the drawing. The commonly used bending equipment is the bending machine. The following is the general process of bending:
- Positioning:
Place the sheet metal material on the workbench of the bending machine and use a measuring tool to accurately position it.
- Adjustment:
Adjust the clamping force, bending force and bending Angle of the bending machine according to the requirements of the drawing.
- Bending:
Send sheet metal material to the bending part of the bending machine and start the machine to bend. Pay attention to control bending speed and Angle.
- Check:
each bending, it is necessary to check whether the bending Angle and size meet the requirements.
- Adjustment:
If you need to fine-tune the Angle and size, you can adjust the bending machine parameters again.
- Completion:
After all the bending is completed, take out the bent parts and carry out the necessary cleaning and inspection.
Step 5: Welding
Sheet metal welding is a plurality of parts together, or a single part edge seam welding, to increase its strength. Common welding methods for sheet metal include TIG welding, MIG/MAG welding, gas shielded welding, laser welding, etc.
Step 6: Polishing
After welding processes, the appearance should be polished again with emery cloth, there can be no edges and corners of the hand side, no welding slag, welding spots, burrs, etc., and the weld should be smooth and smooth.
Step 7: Surface Finish
After the sheet metal parts are processed, they need to be surface-treated to protect the workpiece and enhance its appearance and working life.
Materials & Applications of Sheet Metal Fabrication
Sheet metal processing commonly used materials are cold rolled sheet (SPCC), hot rolled sheet (SHCC), galvanized sheet (SECC, SGCC), copper (CU), brass, red copper, beryllium copper, aluminum plate (6061, 6063, hard aluminum, etc.), stainless steel.
According to the different functions of the product, the selection of materials, Generally, the use and cost of the product should be considered.
According to the different functions of the product, the selection of materials, Generally, the use and cost of the product should be considered.
Cold rolled steel (SPCC):
Mainly used in electroplating and paint parts, low cost, easy to shape, material thickness ≤3.2mm.High strength, but toughness, poor weldability, more hard, brittle, bright surface.
Because the surface is already smooth enough, the finished product does not require a lot of additional surface finishing.
Applications:
- Metal furniture,
- structural parts,
- household appliances,
- water heaters,
- metal containers,
- fan blades, pans,
- computer cabinets, etc.
Galvanized sheet (SECC, SGCC):
Galvanized sheet refers to the surface of the steel plate coated with a layer of metal zinc, to prevent the surface of the steel plate from corrosion, prolong its service life.
Applications:
- Architectural construction,
- home appliances,
- automobile,
- machinery,
- electronics,
- farming etc.
Copper:
Copper has good electrical conductivity, thermal conductivity, ductility and corrosion resistance. It is easy to manufacturing process and has a beautiful appearance.
Applications:
- Architectural industry,
- Aerospace industry,
- Electrical equipment,
- home appliances,
- electromobile.
Brass:
Brass is an alloy of copper and zinc. Brass does not corrode easily in air or water, stressless deformation and has high strength and good machinability.
Applications:
- Marine components,
- conductive components,
- architectural decoration,
- radiator enclosures,
- stamping parts
Red copper:
Has excellent electrical conductivity and thermal conductivity properties. Red copper is often used in the because it does not corrode in air or water.
Applications:
- Marine components,
- conductive components,
- architectural decoration,
- radiator enclosures,
- stamping parts
Beryllium copper:
It is a kind of alloy with simple manufacturing process, good electrical conductivity, good wear resistance, good cold resistance, no spark, corrosion resistance. Beryllium copper is often used in electrical and electronic applications.
Applications:
- Automotive components,
- Glasses,
- Machine parts,
- Temperature controller,
- switches.
Aluminum plate (6061, 6063):
Aluminum has good corrosion resistance, light weight and good heat dissipation. The forming processes is simple and the appearance is beautiful.
Applications:
- Aircraft parts,
- ship parts,
- valve parts,
- Home appliance shell，
- automobile manufacturing,
- construction industry
Stainless steel:
It is a corrosion-resistant alloy that is easy to process and has good heat resistance and processing performance. The costs of stainless steel sheets more than aluminum.
Applications:
- Building decoration,
- aerospace industry,
- chemical engineering,
- mechanical engineering,
- Food processing equipment,
- medical equipment,
- durable and light casings,
- electrical equipment.
Surface Finish of Sheet Metal Fabrication
There are many different types of surface finishes that can be applied to sheet metal fabrications. The most common type of finish is anodizing, which is a process that creates a protective coating on the metal. Other finishes include Sand Blasting, powder coating, painting, and plating.
Anodizing
Anodizing is a process that creates a protective coating on the metal. This type of finish is often used on aluminum, but it can also be used on other metals such as stainless steel and titanium.
Sand Blasting
Sand Blasting is a process that uses high-pressure air to blast sand onto the metal. The surface of the workpiece processed by sandblasting is metallic color, but because the surface is rough, the light is refracted, so there is no metallic luster, and it is the dark surface.
Powder Coating
It is a type of finish that is applied to the metal using a powder.It is more durable than paint and is less likely to chip or fade.
Brushing
Brushing is a process that uses a brush to create a textured finish on the metal. This type of finish is often used on stainless steel and aluminum.
Electroplating
It is a process that uses an electric current to coat the metal with a thin layer of another metal. This type of finish is often used to improve the appearance of the workpiece or to provide protection against corrosion.
Passivation
Passivation is a chemical process that creates a protective oxide layer on the surface of the metal.
Painting
Painting is a type of finish that is applied to the metal using a brush or sprayer. Painting increases the durability of the metal and makes it more resistant to corrosion.
Advantages of Sheet Metal Fabrication
Low cost
Sheet metal fabrication is a very cost effective way to produce metal parts. The process is relatively simple and does not require expensive tools or machines.
High strength
Sheet metal fabrication can be used to create parts that are very strong. The process of fabricating sheet metal parts creates a strong bond between the layers of metal, which results in a strong finished product.
Durability
it can be used to create parts that are very durable. The process of fabricating sheet metal parts creates a strong bond between the layers of metal, which results in a strong finished product.
Light weight parts
Sheet metal is often used to create parts that are durable and light castings. Greatly improve the transportation and use of parts difficulty.
Fast production
Sheet metal fabrication is a very fast way to produce metal parts. The process is relatively simple and can be completed very quickly.
Wide application
It has been widely used in electronic appliances, communications,buildings, airplanes, automobile industry, medical equipment and other fields.
Sheet Metal Design Considerations:
Wall thickness
The wall thickness of a sheet metal part is an important factor to consider during the design process. The sheet thickness should be thick enough to withstand the loads that will be applied to the part, but not so thick that it makes the part too heavy or difficult to fabricate.
Holes
Holes are often needed in sheet metal parts for fasteners, hinges, or other purposes. It is important to consider the size and location of holes during the design process so that they can be easily created during fabrication.
Edges
The edges of a sheet metal part need to be strong enough to withstand the loads that will be applied to the part. It is also important to consider the appearance of the edges during the design process.
Bend Radius
The bend radius of a sheet metal part is the minimum radius that the part can be bent without breaking. The bend radius should be large enough to allow the part to be bent during fabrication, but not so large that it makes the part too difficult to fabricate.
Conclusion
Sheet metal fabrication is a great choice for high strength, durable parts that are also light weight and cost effective. The process is relatively simple and can be completed very quickly. Widely used in many different industries, sheet metal fabrication is a versatile option for your next project.
I hope this article has helped you learn more about what is sheet metal fabrication and how it can be used to create parts for your project and find right sheet metal fabricators. If you have any questions, please feel free to contact me and I will be happy to help. Thanks for reading!
FAQs
Q: How to ensure the accuracy of sheet metal fabrication?
A: The precision of sheet metal processing is mainly affected by processing equipment and processing technology. In order to ensure the machining accuracy, it is necessary to use high-precision machining equipment, and master the correct processing technology and operation method.
Q: How to control the cost of sheet metal fabrication?
A: The cost of sheet metal processing is affected by many factors such as materials, processing technology, equipment and labor. In order to control the cost, you can choose the appropriate materials and processing technology, reasonable allocation of equipment and personnel, improve production efficiency, reduce reject rate, etc.
Q: How to ensure the quality of sheet metal fabrication?
A: The quality of sheet metal processing is affected by many factors such as material, process, equipment and operation. In order to ensure the quality of processing, it is necessary to use high quality materials and equipment, and master the correct processing technology and operation method.
At the same time, the need to strengthen quality management and inspection, to ensure that the product meets the quality requirements.
Author
Gavin Leo is a technical writer at Aria with 8 years of experience in Engineering, He proficient in machining characteristics and surface finish process of various materials. and participated in the development of more than 100complex injection molding and CNC machining projects. He is passionate about sharing his knowledge and experience.