Last updated on August 27th, 2026 at 08:53 am
Busbars
Most fabricated busbars are made from copper or aluminum and can be cut, punched, formed, drilled, plated, or insulated depending on the electrical and mechanical requirements of the system.
Here, we’ll look at where busbars are used, how material choice affects the design, and how our sheet metal fabrication experts manufacture busbars from one-off prototypes to low-volume production runs.
Busbars: An Overview
Busbars provide a compact and organized way to distribute electrical current through a system. Instead of routing an individual wire between every component, a busbar creates a common conductive path that multiple devices can connect to.
This makes busbars useful in electrical panels, switchgear, battery systems, industrial equipment, data centers, renewable energy systems, and other applications where multiple high-current connections need to be managed efficiently.
Busbar Materials: Copper vs. Aluminum
Most busbars are made from copper or aluminum. Both materials can perform very well, but they have different electrical, mechanical, weight, and cost characteristics.
| Factor | Copper Busbar | Aluminum Busbar |
|---|---|---|
| Electrical Conductivity | Higher | Lower than copper |
| Cross-Section for Similar Resistance | Can generally be smaller | Generally requires a larger cross-section |
| Weight | Heavier | Significantly lighter |
| Material Cost | Typically higher | Typically lower |
| Thermal Expansion | Lower | Higher |
| Connection Design | Well-established for many applications | Requires attention to oxide layers, joint design, and mating hardware |
The right material should be selected based on the electrical design, available space, weight target, connection method, environment, material availability, and cost.
Copper is not automatically the only choice for high-current applications, and aluminum is not limited to light-duty systems. Aluminum busbars are widely used in serious power-distribution applications when the design accounts for their larger required cross-section, connection behavior, and thermal expansion.
Busbars at Work: Industries and Applications
You’ll find busbars used across a wide range of applications and industries, including aerospace, construction, marine, mining, telecommunications, transportation, data centers, and renewable energy.
- Electrical panels and switchgear use busbars to distribute power between breakers, switches, and other electrical components.
- Industrial machinery uses busbars to connect motors, drives, power supplies, batteries, and other equipment.
- Power distribution systems use busbars to interconnect transformers, circuit breakers, and other high-current components.
- Data centers use busbars in systems that distribute power to servers, storage systems, and supporting infrastructure.
- Renewable energy systems use busbars in battery storage, inverter, charging, and power-conversion assemblies.
Busbar Alternatives: Other Power Distribution Methods
A busbar is not the only way to distribute electrical power. Depending on the application, engineers may also use flexible conductors, wiring harnesses, power distribution blocks, bus ducts, terminal blocks, printed circuit boards, or other electrical distribution systems.
The right solution depends on factors such as current, voltage, physical routing, available space, serviceability, weight, environmental exposure, and system architecture.
Busbar Finishing: Plating, Coatings, and Insulation
Here at ASM, we’re best known for speed in fabricating precision sheet metal parts. To keep lead times short, we frequently ship busbars raw with no plating or insulation.
When finishing is required, the exact specification should be identified early because plating, masking, contact-surface requirements, and outside processing can affect both cost and lead time.
Busbar plating may be specified for reasons such as:
- Corrosion protection
- Contact-surface performance
- Environmental exposure
- Solderability or connection requirements
- Compatibility with mating components
Insulation is a separate consideration from plating. Electrical clearances, safety requirements, system voltage, and applicable standards may drive whether a busbar needs insulation or another protective covering.
ASM does not provide silicone rubber or heat-shrink tubing, so those requirements should be identified when planning the complete manufacturing and finishing process.
How Approved Sheet Metal Fabricates Busbars
Our sheet metal fabrication team produces busbars using several in-house manufacturing processes. The best process depends on part geometry, material, thickness, feature count, tooling, and quantity.
Turret Punching
We use a turret punch when the busbar contains relatively simple geometry that matches available tooling. Punching can be very efficient for repeated holes and standard features.
Fiber Laser Cutting
We use a laser cutter for more complex profiles, varied hole patterns, prototype geometry, and features that do not justify dedicated punch tooling.
Laser cutting also provides flexibility when several busbar designs or revisions need to be produced without creating new hard tooling.
Press Brake Forming
After cutting, we use a press brake to create bends, offsets, and other formed geometry required by the finished busbar.
Material type, thickness, bend radius, feature placement, and springback all affect how the busbar should be designed and formed.
Secondary Operations
If a critical mounting, mating, or contact feature requires tighter dimensional control than the normal cutting and forming process can provide, a secondary machining or finishing operation may be appropriate.
What Information Does a Busbar Fabricator Need?
A fabricator can manufacture the busbar geometry, but the electrical requirements of the conductor should already be defined by the electrical design.
When submitting a busbar for fabrication, provide:
- Material: Copper or aluminum grade/alloy
- Material thickness: Actual nominal thickness required
- Overall geometry: Complete 3D model and formed shape
- Hole sizes and locations: Including critical mounting and electrical connection holes
- Bend angles and radii: Identify any critical formed geometry
- Tolerances: Clearly identify dimensions that control fit, alignment, or contact
- Finish or plating: Include any required coating specification
- Bare contact areas: Identify surfaces that must remain uncoated or receive selective plating
- Hardware: Specify fasteners or inserted hardware when applicable
- Quantity: Prototype and production quantities can influence the most efficient fabrication process
- Flatness or contact requirements: Identify mating surfaces where dimensional control is especially important
Current rating, temperature rise, voltage, creepage, clearance, and other system-level electrical requirements should be established by the electrical design. ASM can then manufacture the busbar geometry to the specified requirements.
Busbar Tips: Design for Manufacturing (DFM)
When you’re designing a busbar, these DFM tips can help reduce unnecessary manufacturing cost and lead time.
Tolerances
Use standard manufacturing tolerances wherever they meet the functional requirements of the part.
Mounting holes, stacked conductors, electrical-contact features, mating interfaces, and other critical dimensions may require tighter control. The best approach is to identify those specific critical features rather than applying unnecessarily tight tolerances to every dimension on the busbar.
Materials and Thickness
Design around readily available material thicknesses whenever the electrical and mechanical design allows it.
Material availability can vary by copper or aluminum grade, temper, thickness, width, and supplier. An uncommon material specification may increase both material cost and sourcing lead time.
Tooling
Design with standard tooling in mind whenever possible. Standard hole sizes, bend radii, and formed geometry can reduce the need for custom tools or secondary machining.
How Bending Affects a Busbar
Bends are more than a geometric requirement. They can influence both manufacturability and the final location of electrical connection points.
When designing a formed busbar, consider:
- Material and temper: Copper and aluminum alloys have different forming characteristics.
- Bend radius: An appropriate radius reduces the risk of cracking and improves repeatability.
- Springback: The final bend angle can vary depending on material and forming conditions.
- Feature proximity: Holes and cutouts positioned too close to a bend may distort during forming.
- Tolerance stackup: Multiple bends can affect the final position of mounting and contact features.
As a general ASM DFM guideline, keep holes and other critical cut features approximately 3 to 4 times the material thickness away from a bend when possible. The actual requirement depends on material, thickness, bend radius, feature size, and tooling.
Keep Electrical Contact Surfaces in Mind
Electrical contact areas deserve special attention because they may have requirements beyond ordinary sheet metal geometry.
When a surface will mate with another conductor, terminal, or electrical component, consider:
- Whether the surface must remain bare
- Whether selective plating is required
- Flatness or surface requirements
- Hole location and hardware stackup
- Whether burrs or coating could interfere with the joint
- Accessibility for assembly tools and fasteners
Clearly identifying electrical contact surfaces on the drawing helps prevent those features from being treated like ordinary cosmetic or noncritical surfaces during fabrication and finishing.
Common Mistakes in Busbar Design
Busbars may look relatively simple, but design decisions can affect electrical performance, manufacturability, cost, and lead time.
1. Choosing Copper or Aluminum Based Only on Cost
Material selection should account for conductivity, available space, required cross-section, weight, thermal expansion, connection design, environment, and cost.
DFM Tip: Select copper or aluminum based on the complete electrical and mechanical design rather than assuming copper is always better or aluminum is only appropriate for lower-demand applications.
2. Applying Tight Tolerances Everywhere
Tight tolerances can add inspection, secondary machining, setup time, and manufacturing cost without improving the function of the busbar.
DFM Tip: Identify the mounting holes, mating interfaces, contact surfaces, and other dimensions that are actually critical, and allow standard fabrication tolerances elsewhere.
3. Placing Holes Too Close to Bends
Holes, slots, and other features located too close to a bend can stretch or distort during forming.
DFM Tip: Keep critical features approximately 3 to 4 times the material thickness away from bends when possible. Edge distance should be evaluated separately based on hole size, hardware, loading, material, and application requirements.
4. Ignoring Contact-Surface Requirements
A busbar may require bare, plated, masked, or specially controlled surfaces where electrical connections are made.
DFM Tip: Identify contact surfaces and finish requirements on the drawing rather than waiting until after fabrication to determine which areas should remain bare or receive plating.
5. Designing Around Difficult-to-Source Material
An uncommon copper or aluminum grade, temper, or thickness can increase sourcing time and material cost.
DFM Tip: When the electrical design allows flexibility, ask your fabricator which material specifications are readily available before finalizing the design.
6. Ignoring Bend Geometry in Mating Assemblies
Material thickness, bend radius, springback, and multiple bends can all affect the final position of mounting and electrical-contact features.
DFM Tip: Identify the dimensions that control final assembly alignment rather than relying solely on individual bend dimensions.
7. Specifying Plating Too Late
Plating and masking can affect lead time, cost, contact surfaces, and the final manufacturing sequence.
DFM Tip: Define plating, bare areas, masking, and other finishing requirements before quoting whenever possible.
8. Overcomplicating the Geometry
Unnecessary bends, unusual hole sizes, intricate cutouts, or special formed features can increase programming, tooling, forming, and inspection requirements.
DFM Tip: Simplify geometry where it does not affect the electrical or mechanical function of the busbar and design around standard fabrication processes whenever possible.
At ASM, our goal is to manufacture the busbar geometry efficiently while meeting the material, dimensional, and finishing requirements defined by your electrical and mechanical design.
Request a quote for your busbar project, and you’ll hear from us soon!
Sheet Metal Design for Manufacturing
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Sheet Metal Busbar Design FAQ
What exactly are busbars, and why are they essential in electrical systems?
Busbars are metal bars, commonly made of copper or aluminum, that serve as central hubs for distributing electrical currents. They streamline connections between various components like circuit breakers and switches, significantly simplifying power distribution in electrical systems.
What materials are typically used in manufacturing busbars, and how do they differ in application?
Copper and aluminum are the primary materials used due to their excellent electrical conductivity and thermal properties. Copper, akin to an all-terrain boot, is ideal for heavy-duty, high-current applications. Aluminum, more lightweight and cost-effective, suits less demanding scenarios.
Where are busbars used across industries, and what are their common applications?
Busbars find applications in diverse industries like aerospace, construction, data centers, and renewable energy systems. They’re employed in electrical panels, industrial machinery, power distribution systems, and even in connecting renewable energy sources to the grid.
What are the alternatives to busbars in electrical systems, and when might they be more suitable?
While there are no direct substitutes for busbars, alternative solutions like wiring harnesses, conduit systems, PCBs, or power distribution blocks offer advantages in specific scenarios. For instance, wiring harnesses excel in applications that demand routing flexibility.
What fabrication capabilities does ASM offer for busbars, and what design considerations are important when requesting fabrication?
ASM employs turret punches and laser cutters to craft busbars, ensuring precision and customization. Designing busbars with standard tolerances, readily available material thicknesses, and considering standard tooling helps expedite fabrication while minimizing costs and lead times.