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How to Design Sheet Metal Parts | 9 Key Considerations to Optimize Your Designs

Published on July 23, 2024

Designing sheet metal parts is a critical aspect of industrial manufacturing. This article delves into the best practices and key considerations for creating effective and efficient sheet metal designs, ensuring cost-effective production and high-quality products.

Enhance the Metal Fabrication Process with Outsourced Industrial Services

Enhancing the metal fabrication process is essential for companies aiming to stay competitive and efficient. Outsourcing industrial services through a reliable contract manufacturing partner like Alpha Contract Manufacturing Group can significantly streamline your operations.

Alpha Contract Manufacturing Group provides comprehensive services that cover all aspects of metal fabrication, including:

Metal bending: Precision shaping of metals to meet unique specifications.
Metal processing: Expertise in handling various metal strips and sheet metal materials.
Laser cutting: High-precision cutting for complex metal part designs.
Water jet cutting: Cutting through tough materials with high-pressure water jets.

These services ensure that all fabrication needs are met under one roof, simplifying the supply chain and improving efficiency.

Metal Processing Services

9 Key Considerations for Sheet Metal Design

Designing sheet metal parts requires careful consideration of material selection, bend radius, hole sizes, and surface finishes. By adhering to these basic guidelines and leveraging advanced manufacturing processes, you can create high-quality, cost-effective sheet metal components that meet your product design and manufacturing needs.

1. Tolerance

Tolerance refers to the allowable deviation or variation from specified dimensions or features of a part. It is essentially the range within which dimensions, angles, and other geometric properties of the sheet metal part are permitted to vary while still ensuring the part’s functionality and manufacturability.

Tolerance in sheet metal design encompasses various aspects, including linear dimensions, hole sizes, bend angles, surface finishes, and geometric tolerances such as straightness, flatness, and parallelism. For example, a tolerance of ±0.010 inches on a linear dimension means that the actual dimension of the part can vary by up to 0.010 inches from the specified value.

Tolerance values are typically specified in engineering drawings or design documentation and are essential for ensuring that the final manufactured part meets the intended design requirements. Properly defining tolerances is crucial to ensure that parts fit together correctly, function as intended, and can be manufactured within acceptable limits. Tighter tolerances are required for precision components or assemblies, while looser tolerances are acceptable for less critical features or applications.

2. Material Selection

Selecting the right material is fundamental to designing effective sheet metal parts. Each material has distinct properties and mechanical characteristics that influence factors such as bend radius, material flow, and overall durability. Here is a detailed list of viable materials commonly used in sheet metal fabrication:

Stainless Steel

Properties: High strength, corrosion resistance, and excellent durability.
Applications: Ideal for environments exposed to moisture and chemicals, such as kitchen appliances, medical devices, and marine equipment.
Characteristics: Maintains structural integrity under extreme temperatures and pressures. Requires careful consideration of bend radius to prevent cracking.

Carbon Steel

Properties: Strong, durable, and relatively inexpensive compared to stainless steel.
Applications: Widely used in construction, automotive, and heavy machinery.
Characteristics: Prone to rusting if not properly coated or painted. Offers good weldability and machinability. Suitable for applications requiring high strength and rigidity.

Aluminum

Properties: Lightweight, corrosion-resistant, and good thermal conductivity.
Applications: Commonly used in aerospace, automotive, and consumer electronics.
Characteristics: Softer than steel, making it easier to form and bend. Requires special consideration for bending to avoid cracking. Excellent for applications where weight reduction is crucial.

Galvanized Steel

Properties: Carbon steel coated with a layer of zinc for enhanced corrosion resistance.
Applications: Used in outdoor applications, such as roofing, gutters, and automotive body parts.
Characteristics: Offers a good balance between strength and corrosion resistance. The zinc coating can affect the welding and painting processes.

Cold Rolled Steel

Properties: Higher strength and smoother surface finish compared to hot rolled steel.
Applications: Ideal for precision parts, such as automotive components, appliances, and furniture.
Characteristics: Superior surface finish and tighter tolerances. Requires careful handling to avoid surface damage.

Hot Rolled Steel

Properties: More malleable and easier to form compared to cold rolled steel.
Applications: Suitable for construction beams, rail tracks, and heavy machinery parts.
Characteristics: Rougher surface finish and less precise dimensions. Cost-effective for large structural components.

Copper

Properties: Excellent electrical and thermal conductivity, corrosion resistance, and malleability.
Applications: Electrical components, heat exchangers, and decorative elements.
Characteristics: Soft and ductile, allowing for intricate bends and shapes. High cost compared to other materials.

Brass

Properties: Corrosion-resistant, with a low friction coefficient and good electrical conductivity.
Applications: Used in plumbing, electrical connectors, and decorative items.
Characteristics: Easy to machine and form. Provides a distinct yellow-gold appearance.

Titanium

Properties: High strength-to-weight ratio, corrosion resistance, and biocompatibility.
Applications: Aerospace, medical implants, and high-performance automotive parts.
Characteristics: Difficult to machine and form due to its high strength. Very expensive compared to other metals.

Magnesium

Properties: Extremely lightweight with good strength.
Applications: Aerospace, automotive, and portable electronic devices.
Characteristics: Requires careful handling due to flammability. Challenging to machine and form.

Zinc

Properties: Low melting point, corrosion resistance, and good formability.
Applications: Die casting for automotive parts, construction materials, and batteries.
Characteristics: Suitable for casting and forming complex shapes. Typically used as a coating material.

Nickel

Properties: High corrosion resistance, especially in harsh environments.
Applications: Aerospace, chemical processing, and marine applications.
Characteristics: Often used as an alloying element to enhance the properties of other metals.

Choosing the right material for your sheet metal design depends on the specific requirements of your application, including environmental conditions, mechanical stress, and desired durability. Understanding these characteristics helps ensure that your sheet metal components meet the highest standards of quality and functionality.

Key Factors to Consider to Choose a Material for Sheet Metal Parts

3. Sheet Metal Thickness

Sheet metal thickness is a critical factor in design decisions. The thickness of the material influences the bending processes and tools required. For instance, thicker materials need more robust bending tools and different techniques compared to thinner sheets. Ensuring uniform thickness throughout the sheet is essential for achieving consistent bends and minimizing distortion during the fabrication process.

Importance of Sheet Metal Thickness:

Consistent Bends: Uniform thickness helps maintain consistent bend quality.
Minimized Distortion: Reduces the risk of distortion during bending and punching.
Tool Selection: Determines the type of tools and processes needed for fabrication.

4. Bend Radius and Bend Allowance

Adhering to the correct bend radius is crucial to prevent cracking and to achieve the desired bend angle. The bend radius should be consistent and respect the sheet thickness, typically being 1 to 1.5 times the sheet thickness. Bend allowance accounts for the material stretching that occurs during the bending process and ensures accurate final dimensions.

Key Points on Bend Radius and Bend Allowance:

Prevent Cracking: Correct bend radius avoids material cracking.
Consistency: Ensures uniform bends across the sheet.
Material Stretching: Bend allowance compensates for stretching, ensuring precision.

5. Flanges and Bends

Flanges and bends are essential features in sheet metal designs. The minimum flange length should be at least four times the sheet thickness to maintain structural integrity. Proper bend relief must be incorporated to avoid tearing or deformation, especially at the corners. The initial bend angle and bend height must be precisely calculated to achieve accurate bends.

Design Guidelines for Flanges and Bends:

Minimum Flange Length: At least four times the sheet thickness.
Bend Relief: Prevents tearing and deformation at corners.
Accurate Bends: Precise calculation of bend angle and height.

6. Hole Sizes and Punching

When designing holes in sheet metal, the hole diameter should be at least equal to the sheet thickness to prevent distortion. The minimum distance between holes and from the edge to the nearest hole should be at least twice the sheet thickness. Custom tools are often required for unique hole sizes and shapes, impacting tooling costs.

Considerations for Hole Sizes and Punching:

Prevent Distortion: Hole diameter should match sheet thickness.
Spacing: Maintain minimum distance to avoid weakening the material.
Tooling Costs: Unique hole designs require custom tools.

7. Notches and Relief Cuts

Notches and relief cuts ease material deformation during the bending and punching processes. The radius for notches should be at least 0.5 times the sheet thickness. Relief cuts prevent tearing and ensure smooth bends, particularly in corners and intricate designs.

Benefits of Notches and Relief Cuts:

Ease Deformation: Helps in managing material stress during bending.
Prevent Tearing: Relief cuts avoid material tearing.
Smooth Bends: Ensures clean bends in complex shapes.

8. Extruded Holes and Curls

Extruded holes add depth and strength to the holes. Depth control functionality ensures consistent extrusions, while curl features such as rounded edges enhance safety by preventing sharp edges. The radius of the curls must be proportional to the sheet thickness for optimal results.

Advantages of Extruded Holes and Curls:

Strength and Depth: Enhances structural integrity of holes.
Safety: Rounded edges prevent sharp edges.
Proportional Curls: Radius must match sheet thickness.

9. Surface Finish

A smooth surface finish, whether achieved through powder coating, satin surface finish, or other methods, enhances the cosmetic appearance and protects the metal from corrosive environments. The finish should be consistent and suited to the intended application, ensuring both functionality and aesthetic appeal.

Importance of Surface Finish:

Aesthetic Appeal: Improves the cosmetic appearance of the product.
Protection: Safeguards against corrosion and environmental damage.
Consistency: Ensures a uniform and high-quality finish.

By understanding and implementing these key considerations, designers can create high-quality, durable, and efficient sheet metal components that meet precise specifications and performance standards.

How To Choose The Sheet Metal Fabrication Process | 5 Key Factors To Consider

Perfecting Sheet Metal Part Design: The Benefits of Working with a Contract Manufacturer

Designing and fabricating sheet metal parts is a complex process that requires precision, expertise, and access to specialized equipment. Partnering with a contract manufacturer for your sheet metal part design offers numerous benefits, ensuring high-quality production while optimizing costs and efficiency. Read on to learn why working with a contract manufacturer produces the best results.

Expertise in Material Selection and Thickness

Contract manufacturers have extensive knowledge of various sheet metal materials and their physical properties. They can recommend the best material thickness for your project, ensuring durability and performance. Whether you need a single sheet or multiple sheets of metal, they can help you select the right material to balance material costs and performance.

Adherence to Sheet Metal Design Guidelines

Professional contract manufacturers follow strict sheet metal design guidelines to ensure optimal fabrication. They understand the rules for designing sharp corners, corner radius, and bend radius consistent with the thickness of sheet metal. This expertise minimizes metal deformation and distortion of sheet metal during the fabrication process.

Advanced Fabrication Processes

Contract manufacturers use advanced equipment such as laser cutters and plasma cutting tools. These technologies provide precise cuts and bends, even for complex metal part designs. Laser beams allow for intricate details and accurate slot sizes, conical holes, and slot diameters, ensuring a high-quality finished product.

Cost-Effective Solutions

By leveraging the capabilities of a contract manufacturer, you benefit from a low-cost process. They can optimize material costs by recommending the most efficient sheet metal materials and processes. Specialized tooling and size punching tools are used to reduce waste and improve production speed, ultimately lowering overall expenses.

Enhanced Safety and Quality

Safety is paramount in sheet metal fabrication. Contract manufacturers can create curled edges and safer edges to eliminate sharp, untreated edges. Edge-safe practices ensure that the final product is not only functional but also safe to handle and use.

Efficient and Scalable Production

Contract manufacturers offer scalable metal processing services, accommodating both small and large production runs. They manage the entire metal fabrication process, from initial setup to final inspection, ensuring efficiency and consistency. This scalability is crucial for projects that require quick turnaround times or have fluctuating demand.

Comprehensive Quality Control

Contract manufacturers implement rigorous quality control processes to ensure the finished product meets all specifications. They can ensure consistent quality across every piece of sheet metal, resulting in reliable products that meet the highest standards.

Industrial Subcontracting Services

Alpha Contract Manufacturing Group offers an extensive range of outsourced industrial services that help companies save time and money by leveraging specialist knowledge, strategies, and advanced technology without the need for direct investments.

Serving over 800 active customers, Alpha provides services across various sectors:

By outsourcing to Alpha, businesses can reduce operational costs, focus on core competencies, and gain access to a wealth of industry expertise and resources, ultimately enhancing their competitive edge and production capabilities.