Sheet metal fabrication is a comprehensive process that transforms flat sheets of metal into components or products through various methods of cutting, bending, and assembling. The versatility of custom sheet metal fabrication, including surface finishing, forming techniques, and lightweight parts manufacturing, makes it crucial for producing a wide range of products across different industries.
Understanding the key types of fabrication techniques, such as forming with presses, cutting, and bending, is essential for anyone involved in the manufacturing sector. Taiwa has been a leader in the manufacture of sheet metal fabricated products in Taiwan for the last two decades and here, we provide a detailed guide to the subject for our customers’ reference.
What are the Main Types of Sheet Metal Fabrication Processes?
The two main types of sheet metal fabrication are those which use some form of press and die to shape the metal and those that use cutting and bending to create the shapes needed. This is an overview of the key technologies for both of these categories.
Sheet metal fabrication projects involve a wide range of materials and applications, from industrial and commercial to retail and domestic sectors. Choosing the right materials and understanding their mechanical properties are crucial for successful projects involving bending, machining, or welding.
Sheet Metal Forming with Hydraulic or Mechanical Presses
Press forming is one of the most common methods used in sheet metal production. Precision sheet metal fabrication is crucial in achieving high tolerance in forming processes, ensuring that parts meet exact specifications. This process involves placing the sheet metal between a punch and a die, which are then pressed together to form the metal into the desired shape. This method is highly efficient for producing consistent, repeatable parts in large volumes. There are several types of press forming operations:
Stamping:
This involves various operations such as punching, embossing, bending, flanging, and coining. Stamping is used to create detailed or textured surfaces on the metal sheet.
Deep Drawing:
Used to create deep, hollow shapes like pots and pans. The process involves drawing the metal sheet into a die by a mechanical punch.
Progressive Die Stamping:
This combines several of the stamping processes in a row or station and is used for creating complex parts efficiently, as the metal moves through the progressive stamping presses with automated transfer systems.
Sheet Metal Fabrication with Cutting & Bending
Cutting is the first step in sheet metal product fabrication, involving several techniques that allow precise shapes to be cut out of the metal sheet:
Shearing:
This involves cutting straight lines, typically used for cutting large sheets into smaller rectangles or squares before further processing.
Laser Cutting:
Utilizes a high-powered laser beam guided by a computer to achieve high precision and complex cuts. This method is known for its accuracy and clean edges. This technique is vital for complex geometry shapes or high volume cutting where the locational accuracy and quality of the cut are key to the successful assembly of the finished product.
Plasma Cutting:
Suitable for cutting thick metal sheets, plasma cutting uses a jet of hot plasma to melt the metal. It is faster than laser cutting but typically less precise and so is usually not used for the manufacture of precision products. It is most used in heavy industry applications such as preparing thick sheets of metal for the construction of heavy duty machinery, shipping and transportation applications and other large engineered structures.
Waterjet Cutting:
This method uses a high-pressure stream of water, sometimes mixed with an abrasive material, to cut through metal. It does not introduce heat into the material, thus avoiding any heat-affected zones or thermal distortion. If materials are sensitive to temperature then this can be a good option.
Bending:
Bending is the next step in the sheet metal fabrication process, which involves deforming the metal around a single axis to produce a V-shape, U-shape, or channel shape. Bending is performed on CNC bending machines with precision speed and pressure control, with tools or dies that apply force to the metal along the desired bend line.
What is the process at Taiwa for sheet metal fabrication?
Design
After a customer has provided their design drawing the design team will review and optimize it to make sure that there are no areas that could cause issues in production. Whether you are starting from a sketch or a complete 3D design making sure it is ready for production is vital.
Production Planning
In sheet metal production planning the aim is to provide the most cost effective and efficient plan to give customers the best value through material and finishing choices. This includes the systems settings and jigs to be used to achieve the best possible production outcomes.
Laser Cutting and Punching
The fabrication process usually begins with laser cutting and punching which are often combined into a single step with combined systems to reduce production time and potential accuracy issues that can occur when switching between multiple machines in a process.
Bending
Sheet metal bending requires a huge stock of ready to use jigs as well as extensive planning to make sure that the accuracy of the bend, the mechanical strength of the material and the integrity of the surface finish are maintained. Planning and testing the bending plan prior to production is an important step that helps ensure smooth production and stable quality for large batches.
Welding
Argon and CO2 welding are used in our sheet metal welding as this gives us the breadth of capabilities to handle complex or very thin materials as well as heavier components while maintaining surface finish requirements.
Finishing
During finishing we will ensure all surfaces are smooth and perfect and free of imperfections before sending them on to the quality team. This usually involves hand finishing and inspection to remove any burrs and identify and surface finish issues that need to be addressed before quality inspection and assembly.
Inspection
Standardized and rigorous inspection procedures are vital for sheet metal fabrication as any mechanical, geometrical or finish issues need to be identified prior to production. The quality team should also be able to accommodate special inspection regimes to suit your market or customer requirements.
Assembly
Not all companies offer assembly, but having this available within the same company reduces overall product costs and maintains a single point of responsibility for product quality. The assembly team will initially use riveting or screws and bolts for the individual components, including sheet metal components, emphasizing the importance of proper techniques and orientation of riveting nuts. Afterward, the major parts are hand assembled and packaged ready for shipping.
Types of Materials Commonly Used in Sheet Metal Fabrication
Sheet metal fabrication involves a range of metals and alloys, chosen based on factors like weldability, formability, strength, weight, cost, and corrosion resistance. Below is a detailed overview of the most common materials used, focusing on applications relevant to sheet metal fabrication.
Stainless Steel
Composed of several grades grouped into five families—Austenitic, Ferritic, Martensitic, Duplex, and Precipitation Hardening—stainless steel is widely used due to its corrosion resistance. It is commonly used in the fabrication of industrial tanks, catering equipment, and exhaust systems.
Hot Rolled Steel
This material is processed at temperatures above its recrystallization temperature, making it easier to form. Hot rolled steel is ideal for structural components such as frames, plates, and rails where precision is less critical but durability is essential.
Cold Rolled Steel
Cold rolled steel is initially hot rolled, then further processed at low temperatures to increase its hardness and strength. This material is favored for precision applications in sheet metal fabrication, such as in the manufacturing of home appliances, electronic enclosures, and automotive parts.
Aluminum
Known for its excellent strength-to-weight ratio and corrosion resistance, aluminum is a widely used sheet metal material processed from bauxite into pure metal. In sheet metal fabrication, aluminum is used for panels, roofing, and frames due to its lightweight and durability.
Brass
As an alloy of copper and zinc, brass features easy formability and retains high strength after forming. It is often used in decorative applications within sheet metal fabrication, such as in ornaments, plaques, and signage.
Copper
Copper stands out for its malleability and conductivity. In the realm of sheet metal fabrication, it is primarily used for electrical conductors, roofing, and architectural elements due to its durability and aesthetic appeal.
Steel in Sheet Metal Fabrication:
Technical Standards for Sheet Metal Fabrication
In the USA the Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA) is the leading authority in the sheet metal and HVAC industries to guide customers on requirements for sheet metal fabrication from initial design right through to commissioning and certification.
SMACNA is recognized by the American National Standards Institute (ANSI), and develops technical standards and manuals that are accepted worldwide by the construction and code community, as well as local and national government agencies so this is an excellent source of information for all aspects of sheet metal fabrication requirements.
These are the key areas that SMACNA covers for sheet metal fabricated products:
- Duct Construction and Installation: SMACNA provides comprehensive guidelines for HVAC duct construction. Publications include the HVAC Duct Construction Standards – Metal and Flexible, HVAC Systems Duct Design, HVAC Duct Systems Inspection Guide, and HVAC Air Duct Leakage Test Manual.
- Roofing and Architectural Sheet Metal: SMACNA’s Architectural Sheet Metal Standards provide guidelines for the design, fabrication, and installation of architectural sheet metal components1.
- Welding: SMACNA’s Sheet Metal Welding Guide provides best practices for welding in sheet metal fabrication.
- Commissioning: SMACNA’s HVAC Systems Commissioning Manual provides a comprehensive guide to commissioning HVAC systems
SMACNA also offers a large number of white papers on sheet metal fabrication that can be a useful source of reference information for different aspects of this topic.
Applications of Sheet Metal Fabrication
Sheet metal fabrication is a cornerstone in various industries, serving an array of functions from structural to decorative. This technique is integral to creating both aesthetic elements and essential components across diverse sectors. Sheet metal fabrications encompass a wide range of products and custom projects, ensuring high quality and various surface finishes to meet specific requirements.
Case Studies
On our website we have a selection of real world case studies that we have worked on recently. Please select the case study you are interested in to view the details and some images of the products we produced. Our sheet metal fabrication work includes various projects where we shape, cut, and form sheet metal to create diverse products and components.
Consumer Products
Industrial Products
- Networking Cabinets (Data Centers)
- Controller Enclosures (3C Industry)
- Industrial Safety Fencing (Aviation Industry)
- Customizable Metal Fencing (Transportation Industry)
- Steel Frames for Machinery (Printing Industry)
- Electrical Control Box (Manufacturing)
- Sheet Metal Enclosure (Machine Tools)
Advantages of Sheet Metal Fabrication
Sheet metal fabrication encompasses a broad array of processes and techniques, each with its unique set of advantages and limitations. Here’s an overview of the general benefits of using sheet metal fabrication, though a deeper dive into specific processes may be necessary to determine the best fit for your application.
Sheet metal parts are known for their durability and strength, making them ideal for various applications.
Benefits of Sheet Metal Fabrication
Efficient, Cost-effective, and High-Quality Production
Sheet metal fabrication is capable of rapidly producing both prototype parts and large-scale production runs with equal precision. Its adaptability allows for easy customization; if the initial design requires adjustments, subsequent parts can be modified with minimal difficulty compared to other mass production methods. This makes sheet metal both a versatile and economical option for custom part production.
Diverse Materials
Sheet metal fabrication techniques can also accommodate a wide range of materials and are well-suited for environments that require resistance to high temperatures, electrical and thermal conductivity, and corrosion, making its applications widely applicable across many industry requirements.
High Strength-to-Weight Ratio
Sheet metal fabrication is particularly useful for projects where minimizing weight is a priority. Bending sheet metal increases its structural strength significantly, as it enhances stiffness across multiple axes. Thus allowing thinner, lighter materials which are often cheaper than traditionally machined options to be used.
Finishes Commonly Available in Sheet Metal Fabrication
Sheet metal fabricated products can be finished with a variety of treatments to enhance their appearance, durability, and resistance to environmental factors. When you are discussing your product requirements with your manufacturer, this is one of the important specifications that needs to be decided upon.
However it is useful to note that the same product can be supplied with a wide variety of finishing options to suit market needs with little impact upon the production process which makes sheet metal processes particularly suitable for products that require this customizability. Custom sheet metal fabrication offers numerous customization options for finishes, ensuring that the final product meets specific aesthetic and functional requirements.
Powder CoatingThis finish involves applying a free-flowing, dry powder that is cured under heat to form a skin. It is used to create a hard finish that is tougher than conventional paint. Powder coating is available in a wide range of colors and textures, and it provides excellent resistance to chipping, fading, and scratching.
PaintingPainting is one of the most traditional methods of finishing sheet metal. It provides not only aesthetic enhancements but also a protective layer that helps prevent corrosion. Different types of paints can be used depending on the required durability and the environmental conditions the product will face.
ElectroplatingThis process involves covering the metal with a thin layer of another metal, such as chrome, zinc, or nickel, through an electrochemical process. Electroplating is used to improve corrosion resistance, increase surface hardness, and enhance the appearance of the metal.
AnodizingAnodizing is a method used primarily on aluminum and its alloys to form a durable, corrosion-resistant oxide layer on the surface. This oxide layer can also be dyed with various colors to improve aesthetics. Anodizing enhances the natural qualities of aluminum, providing better resistance to wear and tear.
GalvanizingGalvanizing involves coating the metal with a protective layer of zinc to prevent rusting. The most common method is hot-dip galvanizing, where the metal is submerged in molten zinc. This is particularly useful for outdoor metal products as it provides excellent protection against harsh weather conditions.
PassivationPrimarily used for stainless steel, passivation involves treating the metal with a light coating of a protective material, such as a metal oxide, to enhance its corrosion resistance. This process helps to remove iron particles from the surface, making the material more rust-resistant.
Black OxideBlack oxide is a conversion coating for ferrous materials, stainless steel, copper and copper-based alloys, zinc, powdered metals, and silver solder. It is used to add mild corrosion resistance and for appearance.
Satin CoatAlso known as a brushed finish, this finish involves polishing the metal with a fine-bristle brush to create a consistent, unidirectional texture. It is often used for decorative purposes and can hide fingerprints and minor surface imperfections.
SandblastingThis process involves propelling abrasive material against a surface under high pressure to smooth a rough surface, roughen a smooth surface, shape a surface, or remove surface contaminants. This is particularly popular to provide textured finishes to products to enhance their visual appearance.
Sheet Metal Fabrication Glossary
To help customers we have created an extensive glossary of sheet metal fabrication related terms which can help you better understand some of the technical terms that are used in the industry. If you have any questions that are not covered in this article, please contact our customer support team who will be happy to help you with your needs.
The glossary also includes information on various types of sheet metals used in fabrication, such as stainless steel, copper, and aluminum, and the specific techniques for cutting and shaping them.
