Choosing the Right Metal for Your Custom Enclosure

The test labs in your organization are bound to be filled with custom enclosures. Whether you're building the lab from the ground up or reworking one to better suit your next project, you'll need plenty of enclosures to populate your control/test systems needed to analyze your work. One of the first steps in the designing process is choosing the right metal for your custom enclosure.

In this blog post, we will examine some factors to consider when deciding which metal is the best choice for your project. Following that, we’ll review each of our metal options in detail so that you can make an informed choice when starting your next design.

A variety of factors will come into play when deciding which material is right for your unique design:

Environmental Conditions

If you’ll be using your custom enclosure for testing outdoors, you’ll want to choose an ultra-durable, corrosion-resistant metal, along with the proper finishes.

One of the biggest factors to think about when choosing the right metal for your custom enclosure is corrosion resistance. Metals will corrode at different rates when exposed to heat, UV light, harsh chemicals, or moisture.

Aesthetics

Of course, for any enclosure you design, particularly in the prototyping stage, function should always trump form. However, having an aesthetically appealing and professional-looking prototype could be the difference-maker when seeking approval and buzz from your colleagues, stakeholders, and prospective clients.

Each of our metal options offers their own unique strengths when it comes to aesthetics, to help you along further, we offer a wide variety of custom finishing options too. Most metals will be visually in-discriminable if the same finish (particularly powdercoat) is applied. The right combination for your unique project can truly bring your design to the next level visually.

Weight

Weight can also be a crucial factor in determining the most suitable material for your custom enclosure. As an example, when building your test lab you'll often have your custom enclosures stacked on a rack, one on top of the other. If the enclosures are too heavy, it could cause some serious chaos and unwanted damages.

So, the weight of your enclosure could end up being a very important consideration, especially when factoring in the additional weight of your electronics/components once you’ve completed the final build.

The Metals We Offer

Now that we’ve reviewed all the different factors that will go into the decision-making as you complete the preliminary work of designing your custom enclosure, we can now examine each of our stocked sheet metals, and their best use cases.

1. Cold Rolled Steel

• Environmental Considerations: Cold Rolled is not ideal for wet environments and is the least corrosion resistant metal option we carry. However, this can be subverted with the powdercoat finishing option.
• Aesthetics: In terms of aesthetics, like all metals, Cold Rolled is essentially indistinguishable from any other option when powdercoating has been applied. It is important to note that Cold Rolled steel will rust if left uncoated.
• Weight: Cold Rolled is quite heavy and stiff compared to aluminum. Though it is not as strong as Stainless it does have the same stiffness.
• Finishing Options: Bare metal (though not recommended) or powdercoat.

Cold Rolled Steel is ideal for general purpose indoor enclosures. However, it will rust if not coated, so bare metal and grained finishes are not recommended. It can be extremely durable indoors when finished with powdercoat. However, it is not inherently corrosion resistant. Cold Rolled Steel will degrade quickly in harsh or wet environments and is therefore not ideal for outdoor use. It is a very stiff metal compared to aluminum.  For its structural integrity, it is an excellent cost-effective option.

2. Stainless Steel

• Environmental Considerations: Stainless Steel is the most inherently corrosion resistant of our metal options.
• Aesthetics: Stainless Steel is especially striking with grained finish, but many people prefer the look of Stainless Steel on its own.
• Weight: Stainless Steel is close to the same weight as Cold Rolled Steel, with the same stiffness but a higher strength. However, it is heavier than aluminum.
• Finishing Options: Bare metal, grained finish, or powdercoat are all excellent choices for Stainless Steel.

Stainless Steel is the premium solution to corrosion resistance. This is because of its chromium and nickel content. However, that chromium and nickel come at a cost and makes Stainless Steel more expensive than Cold-Rolled Steel, Aluminum or Galvanneal. It is a great choice general purpose enclosures when corrosion or aesthetics are a concern.

3. Aluminum

• Environmental Considerations: Aluminum offers some corrosion resistance, but not to the same extent as Stainless Steel.
• Aesthetics: Aluminum offers many, eye-catching finishing options.
• Weight: Aluminum is the most lightweight metal we offer; however, it does not offer the same strength as other metals.
• Finishing Options: Bare metal, grained finish, and powdercoat are all fantastic finishing options for Aluminum. Aluminum can also be chem-filmed and anodized.

Aluminum is corrosion resistant and lightweight. Its lower stiffness will require a thicker gauge to match that of steel. Finishing options include bare metal, grained finish or powdercoat. If electrical contact is required in your design, the aluminum must be chem-filmed (chromate coated). Chem film can also increase the durability of the Aluminum. Anodizing can be completed to provide a durable oxide coating. Consider Aluminum where minimum weight and/or corrosion resistance are your key priorities.

We carry two different kinds of Aluminum, 5052 Aluminum – H32 and 6061 Aluminum – T6.  For sheet-metal parts, 5052 is preferred, as the metal can bend to a tighter radius than 6061 without cracking. For CNC machined enclosures, 6061 Aluminum is ideal, because the material is softer and more is easily milled.

4. Galvanneal

• Environmental Considerations: Galvanneal is corrosion resistant as long as the coating is intact.
• Aesthetics: Galvanneal has a dull grey finish.
• Weight: The weight of Galvanneal is similar to Cold Rolled Steel.
• Finishing Options: Galvanneal can be completed with a Bare Finish or Powdercoat.

Galvanneal is a low-carbon steel that is coated with zinc and then annealed in order for the zinc to bond into the substrate, via diffusion. This prevents it from flaking off when formed or bent. The finish acts as a primer and thus easily adheres to paint, while also creating a rust-proof surface. Overall, Galvanneal offers good paintability, corrosion resistance, and formability.

5.  Copper

While we do offer Copper within our sheet-metal offerings, it is very rarely used as the material option for an enclosure. Copper offers excellent electrical conductivity; however, it is extremely soft and thus not ideal to form an enclosure.

Customers typically use Copper for bus bars or miscellaneous parts. Contact us to discuss your options.

Conclusion

When designing a custom enclosure for your specific prototyping/testing projects, it’s important to start on the right foot by choosing the metal that will best suit your unique needs.

To recap, here are a few good questions to guide you:

• Where will my enclosure be stored?
• Will my case need to withstand harsh environmental elements?
• How much does weight/weighting factor into my design?
• If you’re still unsure, or you simply just want to talk through your design and what will be the right fit for you, contact us, as we are always happy to help!