Designing parts for sheet metal fabrication is just as important as any other fabrication process. Proper part design can save you a lot of money, shorten lead times and reduce wastage in the long run.
So, before committing to production, ensure your parts are properly optimized for manufacturing.
As an expert in sheet metal fabrication, RapidDone has extensive experience creating high-quality sheet metal parts. In this article, we’ll share tips on properly designing sheet metal parts for fabrication.
Important Terms in Sheet Metal Design
Before we start with the design tips, let’s look at some important terms in sheet metal design.
Gauge: It is a value used to denote the standard sheet metal thickness for a particular material. The gauge varies from metal to metal, especially ferrous and non-ferrous metals.
The higher the metal gauge, the thinner the sheet metal. Common sizes often range from about 30 – 7 gauge.
Hole Size:This refers to the diameter of circular parts on the sheet metal.
Flange Length:This is the distance from the bent section to the edge of the sheet metal.
Bending Radius:The bending radius is the distance from the center of the bending axis to the inner surface of the sheet metal.
Flange Width: This is the width of the sheet metal section that you want to bend
Tips For Designing Sheet Metal Parts
When designing a sheet metal part, you need to follow certain rules so you can obtain the best possible product. Besides, some of the tips are good for sheet metal part cost saving.
Here are some of these rules:
1. Use a Uniform Wall Thickness Throughout the Part
When designing parts, ensure all the walls have the same thickness throughout. This will help reduce material costs as the entire part can be cut from the same sheet metal blank.
2. Specify the Proper Hole Size
When designing holes, always make sure that the hole size is at least equal to the thickness of the sheet metal. This helps prevent tool breakage when punching out the holes in the sheet.
Also, if the holes are too small, it becomes harder to cut them out as the sheet metal can distort or tear during punching.
3. Space the Holes Properly
When designing sheet metal parts, you should always give holes enough clearance from each other and other features. This is because holes can deform or crack if they’re too close to other features on the sheet metal.
Here are some clearance tips for designing holes:
The distance between two holes should be at least two times the thickness of the sheet metal.
The distance between a bend line and a hole should be at least four times the metal’s thickness.
The distance between a hole and the sheet metal’s edge should be at least three times the material thickness.
This will help avoid distortion of the sheet metal when cutting or punching the holes in it.
4. Use The Right Bend Radius
When bending sheet metal, always make sure that the bend radius is at least equal to the thickness of the sheet metal. If the bend radius is smaller, you can have fractures along the bend.
To save costs, it is also advisable to use the same bend radius at all the bends on your part.
Additionally, ensure the flange’s length is at least four times the thickness of the sheet metal. This will make bending the metal much easier.
5. Keep a Uniform Orientation Across All Bends
Using the same orientation for all your bends helps reduce the time spent fabricating the product. If the machinist is bending the product in the same direction, there is no need to reorient it after bending.
So, the fabrication work gets done faster, which reduces the cost.
6. Use Hems on Your Edges
A hem is a fold on the edge of the sheet metal part that turns the sharp edge inwards and gives it a rounded edge. Using a hem makes the product safer as it gets the sharp edges out of the way of the user.
When designing a hem, ensure the hem’s length is at least four times the sheet metal’s thickness. Also, ensure that the bend radius of the fold is at least equal to the sheet metal’s thickness.
7. Limit the Use of Tight Tolerances
Avoid specifying tight tolerances on surfaces and features that aren’t critical to your part’s function. If you can use lower tolerances for the parts, use them.
Parts with tight tolerances take longer to fabricate and inspect. Also, they cost more in the long run. So, to avoid unnecessary costs, limit the use of these tolerances.
8. Simplify Your Design
Complex designs with several folds, bends, etc., take quite a lot of resources to fabricate. In some cases, we might even need to create special tooling to manufacture the product.
Additionally, complex designs raise the risk of defective or scrap parts. So, if you can, avoid designing complex parts for fabrication.
Always go with the simpler option if there is one available.
9. Choose The Right Material
Before choosing a sheet metal material, you must consider several factors like corrosion resistance, manufacturability, structural strength, surface finish, etc.
Some materials, like Stainless Steel, offer excellent physical and aesthetic properties. However, it is costly and relatively difficult to manufacture.
If your projects don’t need a material like that to function properly, you can always go for cheaper alternatives like Aluminum and Carbon Steel.
10. Place Welds in Easy-to-Reach Areas
If you’re still going to weld your sheet metal parts after cutting and bending, makes sure you place the welding points in accessible areas. Placing them in hard-to-reach areas makes welding awkward for the operator and can lead to poor results.
Also, you can consider using permanent or semi-permanent fasteners in place of welding.
You can optimize your sheet metal parts for manufacturing quite easily by using a top-notch fabrication service like RapidDone. Our engineers have extensive experience designing and manufacturing sheet metal parts for various partners, check out more for our sheet metal fabrication service.
We can apply this wealth of knowledge to help you create an optimal manufacturing plan for your sheet metal project.
Send in your drawings and plans today, and let’s work on them!