When it comes to designing and fabricating components, one material stands out as a true champion: sheet metal. Its remarkable attributes make it a go-to choice for various applications, ensuring structural integrity, cost-effectiveness, and limitless possibilities. Join us as we unlock the potential of sheet metal and reveal six invaluable tips to optimize your designs for unparalleled outcomes.

Designing Sheet Metal Parts: When and Why to Utilize Sheet Metal

When designing and fabricating various components, sheet metal is a versatile and efficient material choice. In this section we look into the reasons why sheet metal is commonly employed in numerous applications, highlighting its notable attributes. Additionally, we explore industries where sheet metal finds widespread use.

Why Use Sheet Metal

1. Strength and Durability

Sheet metal possesses exceptional strength and durability, making it an ideal material for applications that require structural integrity and long-lasting performance. Its inherent rigidity allows it to withstand significant loads, impacts, and vibrations without succumbing to deformation or failure. Consequently, sheet metal parts exhibit high resistance to bending, twisting, and other forms of mechanical stress.

2. Cost-Effectiveness

Sheet metal stands out as a cost-effective option for many projects due to its affordability and availability. The efficient manufacturing processes in sheet metal fabrication contribute to its competitive pricing. Additionally, the ability to optimize material usage through nesting and efficient cutting techniques reduces waste and minimizes costs. As a result, sheet metal offers a compelling balance between performance and affordability, making it an attractive choice for designers and manufacturers alike.

3. Versatility

One of the most prominent advantages of sheet metal is its remarkable versatility. It can be easily formed, bent, stamped, or molded into a wide range of shapes and sizes, allowing for intricate designs and customization. The versatility of sheet metal empowers designers to create complex geometries, contours, and features that fulfill specific functional requirements. Moreover, it facilitates integration with other components and systems, enabling seamless assembly and enhancing overall product functionality.

When to Use Sheet Metal

1. Automobile Bodies

Automobile manufacturing extensively employs sheet metal due to its excellent combination of strength, formability, and cost-effectiveness. Sheet metal components form the framework of vehicles, providing structural integrity, impact resistance, and protection for passengers and critical systems. From body panels and doors to fenders and roofs, sheet metal plays a vital role in shaping exterior aesthetics and ensuring the safety of automobiles.

2. HVAC Ductwork

Sheet metal finds widespread use in heating, ventilation, and air conditioning (HVAC) systems, primarily for fabricating ductwork. The ducts responsible for directing and distributing conditioned air throughout buildings require materials that can withstand high temperatures, pressure differentials, and consistent airflow. Sheet metal, such as galvanized steel or aluminum, meets these demands effectively while allowing for customized shapes and dimensions.

3. Chassis for Devices

Various devices and equipment rely on sheet metal chassis to provide structural support, house internal components, and safeguard delicate electronics. Whether it’s medical devices, electronic enclosures, or consumer electronics, sheet metal chassis offer the necessary rigidity, protection, and grounding. Furthermore, the ability to integrate additional features like mounting brackets, connectors, and ventilation openings makes sheet metal an ideal choice for designing chassis that accommodate diverse functional requirements.

Sheet metal has many advantages and is used in a variety of industries. Knowing how to use sheet metal and optimize the design will allow you to further the benefits of sheet metal. Let’s look at 6 ways you can optimize your sheet metal design for a better outcome

6 Tips for Designing with Sheet Metal

Make the Right Material Selection¹

Selecting the right material to do the job you need to accomplish is a crucial element in your design. When selecting the right material consider the following items.

1. Mechanical Properties

The selection of the right sheet metal material and the needed mechanical properties are crucial to a successful design. Different metals, such as steel, aluminum, and stainless steel, offer varying levels of mechanical properties. Assess the anticipated loads, stresses, and environmental conditions the part will encounter to determine the appropriate material that will ensure optimal performance and durability.

2. End Use of the Product

Understanding the intended purpose of the product is essential when choosing sheet metal material. Consider factors such as the product’s function, operating conditions, and expected lifespan. For example, if the component will be exposed to harsh environments or corrosive substances, selecting a corrosion-resistant material like stainless steel may be necessary.

3. Manufacturability

During material selection, it’s important to consider the manufacturability of the chosen sheet metal. Different metals have varying characteristics that affect their formability, weldability, and machinability. Evaluate the fabrication processes involved in creating the desired part, such as bending, stamping, or welding, and choose a material that can easily undergo these operations with still meeting your design goals.

4. Sheet Thickness ³

The thickness of the sheet metal is another critical factor to consider. Thinner gauges offer greater flexibility and are suitable for applications that require intricate bends or complex shapes. Thicker gauges, on the other hand, provide increased strength but may limit the complexity of design features. Evaluate your design requirements to determine the optimal sheet thickness that balances functionality, manufacturability, and cost.

5. Cost Considerations:

While the mechanical properties and suitability for the application are essential, it’s crucial to keep cost considerations in mind during material selection. Some metals may be more expensive or require specialized processing techniques, impacting the overall production cost. Balance the desired performance characteristics with the available budget to select a cost-effective material that meets the requirements of the design.

Designing Features for your Sheet Metal Part

When designing sheet metal it is important to know the various features you want to add and how to add them for the most effective design. Consider the following features to include in your sheet metal design.

1. Hems²

Hems are commonly used in sheet metal design to create secure and smooth edges. A hem involves folding over a section of sheet metal to add rigidity, increase safety by eliminating sharp edges, and provide reinforcement. Hems are particularly useful for joining two or more sheets together, creating a clean and durable seam. When incorporating hems into your design, it is important to consider the material thickness and bend radius to ensure proper formability and structural integrity. It is recommended for hems to have a minimum inside diameter equal to the material thickness and the hems return length to be at least 4x the thickness.

2. Holes²

Integrating holes into sheet metal components serves multiple purposes, such as facilitating assembly, providing ventilation, or accommodating fasteners. When designing holes, factors such as the desired size, shape, and location should be carefully considered. It is important to adhere to minimum hole diameters and edge distances to prevent deformation, cracking, or weakening of the material. Holes and slots should be placed at least 2x material thickness away from any edge. Holes should also be 2.5x the material thickness away from bends and 6x apart from each hole. Additionally, use standardized hole sizes and shapes to streamline manufacturing and minimize costs.

3. Notches and Tabs²

Notches and tabs are useful to design features for sheet metal components that require interlocking or precise alignment during assembly. Notches are cuts made on sheet metal, while tabs are small protrusions that fit into corresponding notches. This design technique ensures accurate positioning and enhances structural stability. It is crucial to determine appropriate dimensions, clearances, and tolerances for notches and tabs to guarantee proper fit and ease of assembly. Notches should be designed to be at least 1x the material thickness and less than 5x the width of the notch. The tab must be at minimum 2x the material thickness and less than 5x the width.

4. Dimples, Embosses, Louvers³

Dimples, embosses, and louvers are design features that can provide additional functionality and aesthetic appeal to sheet metal parts. Dimples are small depressions made on the surface of the sheet metal, serving as an alignment or clearance feature. Embosses, on the other hand, are raised areas that add strength or incorporate branding elements. Louvers are typically used for ventilation or airflow control. When implementing these features, careful consideration should be given to their dimensions, spacing, and location to maintain the structural integrity and functionality of the component. Here are few tips for designing these features

Dimples

• Max Height of Dimple < or = 3x material thickness
• Dimple radius must be > height of dimple

Embosses

• Distance from Emboss to part edge = 3x thickness + width of Emboss / 2
• Height of Emboss must be < or = 4x material thickness

Louvers

• Height of Louver must be > or = 3x material thickness
• Radius of Louver must be > or = Height

Use Flat Pattern to Optimize your Design⁴

By having a flat pattern, you can greatly improve the design of your sheet metal parts. Being able to see where there is waste material and where features can collide are two examples of the benefits of flat patterns.

1. Features Collide

When designing complex sheet metal components with multiple features, such as bends, cutouts, and flanges, it is essential to ensure that these features do not collide or overlap in a flat pattern. Collisions can lead to fabrication issues, such as interference during bending or difficulties in cutting and forming. It is crucial to review the flat pattern carefully to identify any potential collisions and make necessary adjustments to avoid problems during manufacturing. Properly spacing and aligning features in the flat pattern will contribute to smoother fabrication processes.

2. Waste Material

Efficient utilization of sheet metal is crucial to minimize material waste and reduce costs. Designing with the aim of reducing waste material involves strategic planning and optimization of the flat pattern. Consider nesting techniques, which involve arranging multiple parts on a single sheet to maximize material usage. By positioning components strategically, designers can minimize scrap material and achieve higher yield from each sheet. Collaborating with fabricators and leveraging software tools for nesting optimization can help achieve optimal material utilization and minimize waste.

Designing for Bends²

Bends are an important and common feature to have in your sheet metal design. When designing for bends consider the following items.

1. Bend Relief

Bend relief refers to the provision of extra clearance or space at the ends of a bend to prevent material distortion or cracking during the bending process. It involves removing material or creating cutouts at the bend line to relieve stress concentrations. Incorporating bend relief not only improves the overall strength and quality of the bend but also reduces the risk of defects or failures. Bend reliefs can come in many ways with the most common being a rectangular relief and a tear relief. For a rectangular relief, the depth should be greater than the radius of the bend. The width of the relief should be greater than or equal to the material thickness.

2. Bend Height

Bend height refers to the vertical dimension of a bend, representing the distance from the base of the bend to the outer surface of the sheet metal. Proper consideration of bend height is crucial to ensure accurate and consistent bending throughout the fabrication process. Oversized or undersized bend heights can result in defective bends, dimensional inaccuracies, or structural weaknesses. In general the height of a bend should be at least twice the thickness of the material plus the bend radius

3. Bend Radius

Bend radius is a critical parameter in sheet metal design that determines the curvature of a bend. It refers to the radius of the inner arc created during bending. Choosing the right bend radius is essential for maintaining the integrity of the material and preventing cracks or fractures. A smaller bend radius increases the risk of material failure, while a larger bend radius may cause wrinkling or distortion. To save time and money, bends should try to be placed in the same direction when they are in the same plane. Another way to save costs is by making the bend radius consistent.

Selecting the Proper Manufacturing Process⁵

Selecting the right manufacturing process can lead to a high quality product at an effective cost. Here are a few manufacturing processes to consider when designing your sheet metal parts. 

1. Cutting

Cutting is a fundamental step in sheet metal fabrication, and various methods are available for this process. Two commonly used techniques are laser cutting and water jet cutting.

– Laser Cutting: Laser cutting employs a high-powered laser beam to accurately and precisely cut through the sheet metal. It offers versatility in cutting complex shapes and intricate patterns without the need for specialized tooling. Laser cutting is particularly suitable for thin to medium thicknesses and provides clean, smooth edges. It is ideal for projects that require intricate designs and high precision.

– Water Jet Cutting: Water jet cutting uses a highly pressurized jet of water mixed with abrasive materials to cut through the sheet metal. This method is effective for cutting thick materials and can accommodate a wide range of metals and alloys. Water jet cutting produces minimal heat-affected zones and offers a smooth cutting surface. It is advantageous for materials that are sensitive to heat, such as certain alloys or plastics.

2. Mechanical Shearing

Mechanical shearing involves using specialized cutting tools, such as shears or guillotine cutters, to make straight cuts in the sheet metal. This process is typically used for straight cuts in larger sheet metal parts. It is a cost-effective method suitable for high-volume production and can handle a variety of sheet metal thicknesses.

3. Bending

Bending is a process that involves deforming the sheet metal along a straight axis to create angles, curves, or complex shapes. Press brakes are commonly used to perform precise bending operations. The selection of the appropriate bending method depends on the desired bend angle, material thickness, and tolerances required. Bending allows for the creation of structural integrity, functional features, and aesthetic appeal in sheet metal components.

4. Drawing

Drawing is a forming process that transforms flat sheet metal into 3D shapes, typically using dies and punches. This process is commonly used for manufacturing cylindrical or box-like parts, such as cans or enclosures. Drawing can achieve accurate dimensions and uniform wall thickness in the final product. It is important to consider the material’s ability to undergo the drawing process without cracking or excessive thinning.

Creating the Needed Engineering Drawings and Models⁵

When designing sheet metal parts, creating accurate engineering drawings and models is essential for effective communication and seamless fabrication. Proper documentation ensures that the design intent is accurately conveyed to manufacturers and facilitates the production process. Here are some key considerations when creating engineering drawings and models for sheet metal parts:

1. Flat Patterns

Including the flat pattern representation of the sheet metal component in the engineering drawing is important. The flat pattern provides a clear understanding of the part’s 2D shape before bending and forming operations. This information is vital for fabricators to visualize and accurately interpret the design requirements.

2. Include Bend Lines

To facilitate precise bending operations, it is important to clearly indicate bend lines on the engineering drawing. Bend lines help fabricators identify the exact locations where the material will be bent. By providing accurate bend line information, potential errors and misinterpretations during fabrication can be minimized.

3. Bend Table Showing Angle and Direction of Bends

Including a bend table on the engineering drawing provides comprehensive information about the angles and directions of all the bends in the part. The bend table helps fabricators set up their machines and tools correctly, ensuring accurate and consistent bending throughout the manufacturing process. Clearly defining bend angles and directions reduces errors and rework, leading to efficient production.

4. Include All the Information Needed on the Drawing

To ensure seamless fabrication, the engineering drawing should include all the necessary information for manufacturing the sheet metal part. This includes dimensions, tolerances, hole sizes, edge distances, finishes, and any other critical details.

5. Finish, Coating, Plating, etc.

Specify any required finishing treatments, coatings, or plating on the engineering drawing. This information ensures that the sheet metal part receives the appropriate surface treatment, such as painting, powder coating, or anodizing, to meet the desired functional and aesthetic requirements.

The Limitless Possibilities of Sheet Metal

As we conclude our exploration into the world of sheet metal design, one thing becomes abundantly clear: the power and potential of this versatile material are truly awe-inspiring. From its exceptional strength and cost-effectiveness to its limitless design possibilities, sheet metal has cemented its place as an indispensable resource across industries.

To optimize your sheet metal designs for unparalleled outcomes, we have shared six invaluable tips that will empower you to push boundaries and achieve new heights. By paying attention to every detail and implementing smart design practices, you can unlock the true potential of sheet metal and deliver exceptional results.

So, whether you’re envisioning sleek automobile bodies, efficient HVAC ductwork, or sophisticated device chassis, embrace the art of sheet metal design. Let your creativity soar as you leverage the strength and versatility of this remarkable material. With every project, strive for excellence, knowing that sheet metal will continue to reign supreme, enabling you to shape a future where form and function coexist harmoniously.

Article created with the help of ChatGPT

Image by Emslichter from Pixabay

Sources

1. https://www.protolabs.com/resources/design-tips/8-mistakes-to-avoid-when-designing-sheet-metal-parts/
2. https://geomiq.com/sheet-metal-design-guide/
3. https://www.smlease.com/entries/sheet-metal-design/sheetmetal-design-guidelines/
4.  https://ameritexllc.com/blog/5-ways-to-design-sheet-metal-parts-for-better-fabrication/ 
5. https://improvians.com/blogs/Sheet%20metal%20parts.html