Last updated on August 27th, 2026 at 09:38 am
Any job shop can build a box, but designing a high-quality custom sheet metal enclosure requires more than simply creating six sides around a set of components. Material, thickness, bend geometry, access, ventilation, welding, hardware, finishing, environmental requirements, and assembly all influence how the enclosure should be designed and fabricated.
Approved Sheet Metal specializes in short-run and prototype sheet metal enclosures. Here, we’ll explore the decisions engineers should make before sending an enclosure to a fabricator and explain how those choices can affect quality, cost, and lead time.
Sheet Metal Fabricated Enclosures at a Glance
Fabricated sheet metal enclosures are used to protect, organize, support, and provide access to electrical components, controls, machinery, electronics, and other equipment.
Examples include control panel compartments, telecommunications boxes, electronics housings, machinery surrounds, power distribution enclosures, equipment cabinets, and custom covers.
ASM fabricates enclosures across a wide range of sizes, from small handheld housings to large equipment enclosures. Maximum practical dimensions depend on the material, geometry, forming requirements, welding, and finishing processes required for the enclosure.
Crafting a complete enclosure can call on our full range of capabilities, including laser cutting, punching, forming, welding, hardware installation, assembly, finishing, silk screening, and more.
Tips for Designing Fabricated Enclosures
We’ve said it before, and we’ll say it again: just because a design looks great and unfolds properly in SOLIDWORKS doesn’t mean your fabrication partner can manufacture it as designed.
Follow ASM’s guidelines for sheet metal designs, and you’ll be on the path to successful manufacturing. These questions will help you evaluate the enclosure before release.
Is your design formable?
Many enclosures can be produced efficiently using standard press brake tooling, but others contain geometry that makes forming more difficult.
Deep walls, narrow channels, return flanges, large overall dimensions, or nearby features can prevent the part or tooling from clearing the press brake during the complete bend sequence.
An enclosure can therefore flatten correctly in CAD and still be difficult or impossible to form from one piece.
Before calling your design “done,” let our team take a look to verify its formability.
Can the enclosure be formed from one piece?
Whenever possible, designing an enclosure to be formed from fewer pieces can simplify fabrication. A one-piece design can reduce welding, finishing, assembly time, and opportunities for distortion.
However, enclosure depth, flange geometry, bend sequence, press brake access, and overall size can make a one-piece design impractical or impossible. In those situations, the enclosure may need to be fabricated as multiple formed components and welded together.
If cost or lead time is important, ask your fabricator whether a small geometry change could eliminate a welded seam or allow the enclosure to be formed from fewer individual parts.
Does your design call for welding?
Some enclosure designs can only be completed with the addition of welding services.
Welding adds manufacturing operations and introduces localized heat, which can affect flatness, alignment, and dimensional control. Cosmetic weld requirements can also add grinding, blending, or other finishing steps.
When possible, identify weld locations, weld types, and cosmetic requirements on the drawing so your fabricator understands exactly what the finished enclosure needs to look like.
Communicate early with ASM to ensure we can build your enclosure the way you’ve designed it.
Does your design include special features?
From hardware like hinges, PEM® fasteners, handles, latches, and pop rivets to formed features such as embossments and louvers, special features play a major role in determining how an enclosure is manufactured.
Hardware may need to be sourced or supplied, while formed features need to be compatible with material thickness, nearby geometry, and available tooling.
ASM provides numerous free resources to help you achieve an optimized design.
How will technicians access the enclosure?
Doors, removable covers, and service panels should be considered early in the enclosure design process.
The best approach depends on how frequently the enclosure needs to be opened, whether internal components must be serviced in the field, and whether the panel needs to be completely removable.
Common options include:
- Hinged doors
- Lift-off panels
- Removable screw-mounted covers
- Captive hardware
- Latches
- PEM® nuts and studs
- Quick-access service panels
Also consider hardware location relative to bends, edges, internal components, and other mounting features. Designing access and hardware into the enclosure from the beginning can prevent clearance and assembly problems later.
Does the enclosure need ventilation?
Electronic and electrical enclosures may require ventilation to manage heat generated by the components inside.
Depending on the application, ventilation can be incorporated using louvers, perforations, vent patterns, fans, or combinations of these features.
Ventilation should be considered early because the size and location of openings can affect enclosure strength, component layout, EMI performance, environmental protection, and manufacturability.
If your enclosure contains heat-generating components, review our sheet metal enclosure ventilation design guide before finalizing your design.
Does your design require custom tooling?
Custom tooling can increase both cost and lead time. Designing around existing punches, embossment tools, louver tools, bend tooling, and other standard shop capabilities can help eliminate unnecessary tooling purchases or machining.
You’ll be glad to know that ASM’s complete tooling library is available for engineers to access when designing parts.
Finishing Considerations for Fabricated Enclosures
Numerous finishes are available for sheet metal enclosures, but finish choice can affect dimensions, corrosion resistance, appearance, cost, and lead time.
Powder coating
Powder coating is commonly used on fabricated enclosures because it provides a durable protective and cosmetic finish in a wide range of colors and textures.
When selecting a powder, consider availability. Specialty colors or powders may require minimum purchase quantities or additional lead time.
Enclosure size can also affect finishing options because the part must fit inside the coater’s booth and cure oven.
Remember that powder coating adds measurable film thickness. Tight-fit holes, slots, mating surfaces, threads, grounding locations, and other critical features may require dimensional compensation or masking.
Plating
Plating can provide corrosion protection, electrical performance, or other surface properties depending on the material and application.
Large enclosures can be more difficult and expensive to plate because they may require a finishing vendor with tanks large enough to accommodate the complete part.
If a plating specification is important to the design, include it before quoting so vendor capability, masking, and finishing sequence can be reviewed early.
Silk screening
We frequently provide silk screening for short-run and prototype sheet metal enclosures.
Silk-screened graphics can identify ports, switches, controls, warning labels, instructions, or electrical connections and can also add logos and other branding elements.
If custom artwork is required, provide the graphics file along with the enclosure design and identify the desired placement and orientation.
Electrogalvanized or pre-plated steel
Many ASM customers use electrogalvanized or other pre-coated steel when corrosion protection is needed without applying plating after fabrication.
Depending on the enclosure’s environment and appearance requirements, the material may remain unfinished or receive a final powder coat or wet paint finish.
Remember that cutting, forming, and welding can affect factory-applied coatings, so the complete manufacturing process should be considered when corrosion protection is critical.
How Sheet Metal Enclosures Benefit Your Application
Damage prevention
Properly designed enclosures help protect electronics, machinery, controls, and other components from physical contact, debris, and environmental exposure.
The actual level of protection depends on the enclosure design, seams, openings, doors, gaskets, material, and finish.
Workplace safety
Properly designed sheet metal enclosures can help protect personnel from accidental contact with electrical components, moving equipment, and other potential hazards.
The required level of protection depends on the equipment, environment, and applicable safety requirements.
EMI shielding
Conductive sheet metal enclosures can contribute to shielding electronic components and devices from electromagnetic interference (EMI).
Actual shielding performance depends on material conductivity, electrical continuity between panels, seams, openings, ventilation, gaskets, coatings, and the overall enclosure design.
Heat dissipation
Metal’s thermal conductivity can help transfer heat away from internal components, while properly designed ventilation, fans, and airflow paths can further improve thermal management.
The enclosure itself should not be assumed to solve a thermal problem without considering the amount of heat generated, component layout, airflow, and surrounding environment.
Complete customization
Custom-fabricated enclosures can be designed around the exact components, mounting locations, access requirements, and overall geometry of the application.
Aesthetic appeal
Sheet metal enclosures can also be designed for appearance using controlled weld finishing, powder coating, anodizing, silk screening, engraving, and other finishing options.
Choosing the Best Material for Your Fabricated Enclosures
ASM fabricates enclosures from many different materials. The best choice depends on weight, strength, corrosion resistance, formability, finishing requirements, environment, and cost.
| Material | Good Choice When | Key Design Consideration |
|---|---|---|
| 5052 Aluminum | Low weight, corrosion resistance, and good formability are priorities | Excellent choice for formed enclosures and compatible with many common finishes |
| Cold-Rolled Steel | Strength and material cost are priorities | Typically requires a protective finish when corrosion resistance is needed |
| 304 Stainless Steel | Durability and corrosion resistance are important | Higher material and fabrication cost than standard steel |
| 316 Stainless Steel | The enclosure will operate in a more demanding corrosive environment | Greater corrosion resistance but typically higher cost than 304 |
| Galvanized or Pre-Plated Steel | Corrosion protection is needed without post-fabrication plating | Cutting, forming, and welding can affect the existing coating |
For additional material guidance, review our resources on stainless steel, aluminum, and galvanized steel.
Ultimately, the application’s requirements should determine the material. ASM can help evaluate options based on durability, corrosion resistance, electrical conductivity, weight, cost, formability, and finishing requirements.
The Industries Using Sheet Metal Enclosures
Every industry ASM serves uses enclosures in one form or another.
- The electronics industry uses fabricated enclosures to house circuit boards, power supplies, controls, routers, switches, and other electronic components.
- In the telecommunications industry, enclosures protect networking devices, communications hardware, and supporting electronics.
- Throughout industrial manufacturing, sheet metal enclosures surround control systems, machinery components, and power distribution equipment.
- Medical equipment companies use fabricated enclosures to protect sensitive electronics, monitors, controls, and other components used in medical equipment.
- The automotive industry uses fabricated enclosures for electronics, control modules, power systems, and other vehicle components.
- Sheet metal enclosures are widely used in the aerospace and defense industries to house avionics, communication systems, radar equipment, and other sensitive electronics.
- Across the renewable energy industry, enclosures protect electrical components, controls, inverters, batteries, and other power-management equipment.
Designing an Enclosure Around Environmental and Regulatory Requirements
If your finished product must meet an IP, NEMA, UL, or other industry requirement, communicate that requirement before fabrication begins.
The enclosure’s material, seams, openings, doors, gaskets, hardware, ventilation, and finish can all affect the finished product’s ability to meet the required standard.
Fabricating an enclosure to a drawing does not by itself certify the finished product to a particular rating. Engineers should identify the applicable requirements and incorporate them into the enclosure design and specifications.
Ingress Protection (IP) and NEMA Requirements
Enclosures exposed to dust, moisture, water, or outdoor conditions may be designed around a specified IP or NEMA requirement.
Meeting those requirements can affect:
- Seam construction
- Door and cover design
- Gaskets
- Fastener locations
- Ventilation openings
- Cable entry points
- Drainage
- Material and finish selection
If your application has a specific environmental protection requirement, include it with your RFQ so potential fabrication concerns can be identified during DFM review.
EMI and RFI Shielding
Electromagnetic interference (EMI) and radio frequency interference (RFI) can affect sensitive electronics.
Material selection, electrical continuity between panels, seams, openings, conductive gaskets, coatings, and ventilation features can all influence shielding performance.
Because openings and nonconductive finishes can interrupt electrical continuity, EMI requirements should be identified before the enclosure geometry and finishing specifications are finalized.
Corrosion Resistance
For enclosures exposed to moisture, chemicals, salt, or other corrosive environments, material and finish selection becomes especially important.
Stainless steel, aluminum, galvanized or pre-plated steel, powder coating, anodizing, plating, and other finishing options may be appropriate depending on the application.
The correct combination should be based on the enclosure’s operating environment, expected service life, appearance requirements, and applicable product specifications.
What Should You Send Your Sheet Metal Enclosure Fabricator?
Providing complete design information helps your fabricator quote accurately, identify potential manufacturing issues, and move the enclosure into production faster.
For an efficient DFM review and quoting process, provide as much of the following information as possible:
- 3D CAD model of the enclosure and individual fabricated components
- 2D drawings identifying critical dimensions and tolerances
- Material and thickness
- Hardware part numbers and installation requirements
- Welding requirements, including cosmetic or finishing expectations
- Finish specifications, including powder coat, plating, anodizing, or other treatments
- Masking requirements for threaded holes, grounding points, mating surfaces, or other critical areas
- Silk-screening or graphics files, when applicable
- Assembly requirements
- Environmental, electrical, or regulatory requirements that may affect the enclosure design
Clearly identifying critical requirements allows ASM to focus its DFM review on the features that matter most to your enclosure’s fit, function, cost, and lead time.
ASM Is Your Partner for Prototype and Low-Volume Fabricated Enclosures
Our prototype and low-volume specialists combine cutting, forming, welding, hardware insertion, assembly, and finishing capabilities with practical sheet metal DFM knowledge.
Whether your enclosure is a simple formed box or a complex welded assembly with doors, hardware, ventilation, finishing, and internal components, ASM can review the design and help identify manufacturing issues before production begins.
Fabricated Enclosures FAQ
What types of enclosures can ASM fabricate?
ASM can fabricate a wide variety of enclosures, including those used for computer and smartphone cases, machinery surrounds, control panel compartments, telecommunications boxes, and water distribution chambers. We handle sizes ranging from as small as a human hand to as large as a commercial oven.
How does ASM ensure my design is manufacturable?
Before finalizing your design, ASM’s team will review it to verify formability and manufacturability. We offer guidelines to ensure your design meets our fabrication capabilities, addressing potential challenges such as oversized enclosures or unique features that might affect pricing, lead time, and functionality.
What finishing options does ASM offer for sheet metal enclosures?
ASM provides several finishing options, including powder coating, plating, silk screening, and leaving electrogalvanized steel unfinished. Each option has specific considerations regarding availability, cost, and suitability for different enclosure sizes. Our team can help you choose the best finish for your project.
Which materials does ASM use for fabricating enclosures?
ASM fabricates enclosures using materials like steel (including stainless steel for rust resistance), aluminum (for lightweight and corrosion resistance), and galvanized steel (for cost-efficiency and durability). We help you select the material that best fits your application’s requirements for durability, corrosion resistance, conductivity, weight, and cost.
How do sheet metal enclosures benefit my application?
Sheet metal enclosures offer multiple advantages, including damage prevention, workplace safety, EMI shielding, heat dissipation, complete customization, and aesthetic appeal. These benefits make them suitable for a wide range of industries such as electronics, telecommunications, industrial manufacturing, medical equipment, automotive, aerospace, defense, and renewable energy.