Sheet Metal Fabrication: Everything You Need to Know

Table of Contents: 

1. Introduction
2. The Process of Sheet Metal Fabrication
3. Materials & Applications of Sheet Metal Fabrication
4. Surface Finish of Sheet Metal Fabrication
5. Advantages of Sheet Metal Fabrication
6. Conclusion

Sheet metal fabrication is all about crafting parts from thin sheets of metal. Whether it’s shaping straightforward designs or creating intricate components, this process covers it all. In this article, we’ll delve into what sheet metal fabrication entails and offer insights into designing and producing products through this method.

First, cut metal into flat sheets. These metal sheets are then formed into the desired shape using various processes, such as stamping, bending, or welding. Finally, the part is finished by adding a coating or surface treatment.

Step 1: Cutting sheet metal materials

There are 5 methods for cutting materials for sheet metal fabrication processes:

• Shearing: This involves using straight-cutting blades to make straight-line cuts in sheet metal. It’s suitable for cutting large pieces quickly and is often used for simple shapes and straight edges.
• Laser cutting: Laser cutting uses a high-powered laser beam to cut through sheet metal. It offers precision and versatility, allowing for intricate designs and complex shapes to be cut with ease.
• Water jet cutting: Water jet cutting involves using a high-pressure stream of water mixed with an abrasive substance to cut through sheet metal. It’s suitable for cutting materials that may be sensitive to high temperatures and offers precise cutting with minimal material distortion.
• Plasma cutting: Plasma cutting uses a plasma torch to cut through electrically conductive materials, including sheet metal. It’s a fast and efficient method, suitable for cutting thick materials and producing clean edges.
• Mechanical cutting: Mechanical cutting methods, such as sawing or milling, involve using mechanical tools to cut through sheet metal. While not as common in sheet metal fabrication, these methods can be useful for specific applications or materials.

Step 2: Punching & Broaching

Punching is a sheet metal fabrication method that uses a punch to create holes or shapes in the metal. It can be done with various tools, like an automatic punch, a hand punch, or a CNC machine.

There are three types of punching:

• Single punching: This method involves using a single punch and die set to create a hole or feature in the sheet metal. The punch is forced through the material, cutting out the desired shape. Single punching is suitable for simple hole patterns or individual features.
• Nibbling: Nibbling, also known as notching, is a process where multiple overlapping punches are used to gradually remove material from the sheet metal. It’s often used to create irregular shapes and internal cutouts.
• Progressive punching: Progressive punching involves a series of sequential punches and dies mounted on a single tool. Progressive punching is efficient for high-volume production of parts with multiple features.

Step 3: Pressing Rivet

When riveting nuts, screws, or other fasteners to sheet metal components using hydraulic riveting machines or punches, it’s crucial to ensure proper orientation of the riveting nuts.

Step 4: Sheet Metal Bending

Sheet metal bending involves transforming 2D flat pieces into 3D parts by folding. This process requires a folding bed and bending mold to be completed, following specific bending orders and steps. It entails bending sheet metal into the desired shape and angle as specified in the drawing.

Step 5: Welding

Sheet metal welding involves joining multiple parts together or welding the edges of a single part to enhance its strength. Common welding techniques for sheet metal include TIG welding, MIG/MAG welding, gas-shielded welding, laser welding, and more.

Step 6: Polishing

Following welding procedures, the surface should be polished using emery cloth to eliminate any rough edges, welding slag, spots, burrs, etc. The welded area must be smooth and seamless, with no visible imperfections.

Step 7: Surface Finish

Upon completion of processing sheet metal parts, surface treatment is necessary to safeguard the workpiece, improve its appearance, and prolong its operational lifespan.

Sheet metal fabrication involves working with thin sheets of metal to create various components. Here’s an overview of common materials used in sheet metal fabrication and their applications:

• Steel: Steel is one of the most widely used materials in sheet metal fabrication due to its strength, durability and versatility. It comes in various grades and finishes, including mild steel, stainless steel and galvanized steel. Mild steel is often chosen for its affordability and ease of fabrication, while stainless steel offers corrosion resistance, making it suitable for applications in harsh environments like marine or food processing industries.
• Aluminum: Aluminum is valued for its lightweight properties, corrosion resistance, and conductivity. It’s commonly used in industries such as aerospace, automotive, and electronics. Aluminum alloys offer a wide range of mechanical properties and can be easily formed and welded, making them suitable for intricate designs.
• Copper: Copper is prized for its excellent conductivity, corrosion resistance, and aesthetic appeal. It’s commonly used in electrical and electronic applications where high conductivity is essential. Copper sheet metal is also utilized in architectural applications.
• Brass and Bronze: Brass and bronze are alloys of copper with varying amounts of zinc or tin. They offer a unique combination of properties, including corrosion resistance, machinability, and aesthetic appeal. Brass is often used in decorative applications, hardware, and musical instruments, while bronze is favoured for its strength and wear resistance in applications such as bearings and bushings.
• Titanium: Titanium is valued for its high strength-to-weight ratio, corrosion resistance, and biocompatibility. It’s commonly used in aerospace, medical, and marine applications where lightweight, durable materials are required.

There are plenty of types of surface finishes that can be applied to sheet metal fabrications. The most common type of finish is anodizing and other finishes include sand blasting, powder coating, painting and plating. Let’s check them out:

• Anodizing: Anodizing is a method that forms a protective coating on metal surfaces. While commonly applied to aluminum, it can also be utilized on other metals like stainless steel and titanium.
• Sand blasting: Sandblasting involves using high-pressure air to propel sand onto metal surfaces. While this process results in a metallic-coloured surface on the workpiece, its rough texture refracts light, resulting in a lack of metallic lustre and a darker appearance.
• Powder coating: This finish is applied to metal using a powder rather than paint. It offers enhanced durability compared to paint, making it less susceptible to chipping or fading.
• Electroplating: This process involves applying a thin layer of another metal onto the surface of the metal using an electric current. Such a finish is commonly employed to enhance the appearance of the workpiece or to provide protection against corrosion.

Here are some advantages:

• Versatility: Sheet metal fabrication offers versatility in design, allowing for the creation of complex shapes and structures to meet specific requirements.
• Strength: Sheet metal is inherently strong and durable, providing robustness and stability to fabricated components and products.
• Efficiency: Sheet metal fabrication processes, such as cutting, bending, and welding, can be automated or performed rapidly, resulting in efficient production and shorter lead times.
• Customization: Sheet metal fabrication allows for customization of designs to suit unique project needs, whether it’s prototyping, one-off production or mass manufacturing.
• Material variety: Sheet metal comes in a variety of materials, including steel, aluminum, copper, and alloys, providing flexibility in material selection based on factors such as strength, corrosion resistance, and conductivity.
• Precision: With advancements in technology and machinery, sheet metal fabrication offers high precision and accuracy in producing components with tight tolerances.

Sheet metal fabrication is a great choice for high-strength, durable parts that are also lightweight and cost-effective. The process is relatively simple and can be completed 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 the right sheet metal fabricators.