Sheet Metal Design Guide for Product Manufacturing

Sheet Metal Design Guide

Do you understand the basics of sheet metal design? When designing a product that will be manufactured using sheet metal, it’s essential to know the sheet metal design guidelines. 

In this guide, we’ll cover some of the most critical aspects of sheet metal design. We’ll also discuss the different types of sheet metal fabrication processes available so that you can choose the best process for your product.

By understanding these concepts, you’ll be able to create designs that are not only functional but also attractive and easy to manufacture.

So whether you’re an abecedarian or an experienced designer, read on for all the information you can get started with sheet metal design!

Forming Basics Of Sheet Metal Design

In its most basic form, sheet metal is a simple piece that has been cut and bent into the desired shape.

However, the process of sheet metal design is anything but simple. In order to create a quality sheet metal product, engineers must take several factors into account, including the type of metal to be used, the K-factor, the thickness of the metal, the bending of the metal, and the manufacturing process to be used.

The Metal Sheet Thickness 

Thicker sheet metals are often used for products that will be subject to high levels of stress or impact, such as car frames or agricultural equipment. Thinner metals are better suited for products that need to be flexible or lightweight, such as electronic components or HVAC ductwork. 

sheet metal thickness

The Type Of Metal

The type of metal also plays a role in sheet metal design.

Softer metals, such as aluminum, are often chosen for products that need to be formed into complex shapes. Harder metals, such as steel or titanium, are typically used for products that require a high level of strength or durability.

types of metal

The Bending Of Metal

  • Bend line: the point at which the sheet metal will be bent.
  • Bend radius: the curvature that can be achieved in a sheet of metal without causing it to fracture or become damaged. The final bend radius will be greater than initially formed and the final bend angle will be smaller. 
  • Bend angle: the degree to which a piece of sheet metal is bent.
  • Neutral axis: the centerline of a cross-section of a beam or other structural element.
  • Bend allowance: the neutral axis length between the inside and outside of the bend.
  • K-factor: represents the amount of distortion that occurs when a piece of metal is bent. The higher K-factor means that more distortion will occur.
bending sheet metal

By understanding the basics of sheet metal design, engineers can create solid and aesthetic products.

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Basic Sheet Metal Fabrication Operations

Sheet metal fabrication is a complex process that involves a range of techniques to shape and form metal sheets into various products.

These techniques require advanced skills and expertise to achieve the desired results. However, knowing the basics of the four main sheet metal fabrication techniques – cutting, bending, stamping, and punching – can help you understand the intricacies of the process.


Cutting is one of the most crucial sheet metal fabrication techniques, as it involves separating the sheet metal into custom shapes and sizes. A few methods of sheet metal cutting include shearing, laser cutting, plasma cutting, and water jet cutting.

Shearing is a cost-effective technique for cutting straight lines or simple shapes, while laser cutting is a more precise option suitable for intricate designs.

On the other hand, plasma cutting is an excellent choice for cutting through different materials, whereas water jet cutting can cut through hard metals with superior precision.

Laser Beam Flame Cutting


Bending is the process of manipulating sheet metal to create angles and curves. Different methods of bending, including press braking, roll forming, and folding are used in sheet metal fabrication. Press bending, also known as brake forming, utilizes hydraulic or mechanical presses to bend sheet metal to specific angles and shapes.

Roll forming, commonly used for long sheet metal pieces like pipes, channels, and I-beams, involves passing the sheet metal through a series of rollers that bend it gradually. Similarly, in folding, the sheet metal material is bent into multiple angles using a press brake.


Stamping, also known as pressing, is the process of transforming flat metal sheets into the desired shape by pressing them against a machine or die. Sheet metal forming can be done through blanking, embossing, coining, and flanging.

In blanking, the stamping process cuts a piece from a larger sheet, whereas, in embossing, the sheet metal is pushed into a die to create a pattern or design. coining is a type of stamping that consists of forming metal with a blunt die to create a high-quality surface finish.

Lastly, in flanging, the technique is used to add flanges to sheet metal edges or surfaces.

sheet metal fabrication services


Punching is the process of creating holes, slots, or other openings in the sheet metal. And punching is done using a punch and die set. These sets come in various shapes and sizes to create a range of designs.

Punching can create accurate and consistent holes and is a faster and cost-effective way of creating holes in sheet metal. Punching is done by setting up the punch and die set on the machine bed and manually placing the metal sheet between them for the desired punch-out openings.

In conclusion, sheet metal fabrication involves various techniques and methods to cut, bend, stamp, and punch sheet metal to create a range of products. By understanding the basics of these four main techniques, one can understand and appreciate the hard work and skill that goes into sheet metal fabrication.

Sheet Metal Material Selection

The selection of sheet metal material is the crucial part involved in the product. When it comes to choosing the correct material for a project, there are many factors to consider.

You can determine your choice of sheet metal material based on the following factors:


Desired Strength

Durability Of The Finished Product

Resistance To Corrosion.



Advantages and Limitations of Using Sheet Metal for Fabrication

Advantages of Sheet Metal Design

1. High Strength: Sheet metal is incredibly strong and durable, making it ideal for creating sturdy structures and products.

2. Versatility: Sheet metal can be easily molded and shaped into complex designs, which means that it can be used for a variety of fabrication projects.

3. Customizable: Sheet metal can be easily cut, bent, punched, and stamped to create custom shapes and designs.

4. Economical: Sheet metal is relatively inexpensive compared to other materials like aluminum or carbon fiber, making it a cost-effective choice for many projects.

5. Resistant to Corrosion: Sheet metal is often coated or treated to resist corrosion and rust, which makes it ideal for use in outdoor environments.

Limitations of Sheet Metal Design

1. Limited Thickness: Sheet metal comes in a limited range of thicknesses, which can limit its structural strength.

2. Prone to Dents and Scratches: Sheet metal is susceptible to dents and scratches, which can affect its appearance and structural integrity.

3. Limited Heat Resistance: Sheet metal can warp or bend when exposed to high temperatures, which limits its use in high-temperature applications.

4. Limited Color Options: The color options for sheet metal are limited compared to other materials, which can limit the design options.

5. Tools and Equipment: Sheet metal fabrication requires specialized tools and equipment, which can be expensive and may require specialized skills to operate effectively.

Overall, sheet metal is a versatile and cost-effective material that can be used for a variety of fabrication projects. However, it also has some limitations that should be considered when choosing a material for a project.

Recommend For The Sheet Metal Design

Diameter Of Sheet Metal Holes

As a general rule, the diameter of the hole should be at least three times the thickness of the material. We recommend that the minimum inside diameter equals the sheet metal thickness and a hem return length of 6x material thickness.

Holes and slots should have a diameter at least as large as the thickness of the material or 1.00 mm (0.04″) – whichever is greater.

This rule helps to ensure that the hole is strong enough to prop up the weight of the material and prevents the edges of the hole from tearing.

Length For Bending The Sheet Metal

The recommended length for bending the sheet metal, the thickness of the metal, the type of metal, and the size of the project will have an impact on the length.

A +/- 1-degree tolerance on all bend angles is generally acceptable in the industry. The flange length must be at least 4 times the material thickness.

It is typically recommended that the sheet metal be bent at least two inches longer than necessary.

bend length

Hole Distance From The Bent Edge

The recommended hole distance from a bent edge is 2 1/2 times the material thickness. This ensures that the metal has enough strength to withstand bent stress.

Extruded hole to part edge (B) = 3T + D/2

The metal could crack or break if the holes are too close to the edge. The recommended hole distance also helps prevent the metal from stretching or tearing when bent.

Hole Distance

Distance Between Two Holes

Generally, the distance between two holes should be at least triple the diameter of the hole. This rule applies to both round and oblong holes.

By following these recommendations, you can ensure that your sheet metal project will be solid and durable.

Sheet Metal Design Tips

Designing with sheet metal can be challenging, but with these design hints, you’ll be on your way to creating strong, functional parts.

1.       Don’t forget bend reliefs; the sharper the bend, the greater the relief needed.

2.       When working with slots or cutouts, be sure to account for their effects on the part’s overall strength.

3.       Be sure to take into account that the sheet metal is whether entirely flat.

4.       Avoid using the wrong type of fastener.

5.       Be sure to take into account the thickness of the sheet metal.

6.       Avoid using 3D models without any bending.

7.       Be sure to take into account the strength of the U-slot.

With these hints in mind, you’ll be well on your way to designing robust and functional sheet metal parts.


Designing sheet metal parts is a process that involves several steps, from the initial concept to the final product.

Following this article’s guidelines, you can streamline your design process and ensure that your final product meets all your manufacturing requirements.

Do you have any other tips for designing sheet metal parts? Or do you need to produce sheet metal parts? Please contact us now!