Expanded copper foil is a thin sheet of copper that has been precision-slit and stretched into a mesh with a uniform pattern of openings. This process produces a copper expanded metal mesh that offers significant advantages over traditional foils or wire meshes.

Expanded copper foil is created from a single continuous piece of copper, which means there are no woven joints or welds – yielding a stronger, more stable mesh that still allows air, light, and fluids to pass through.

CThru Metals, a trusted U.S. manufacturer of copper expanded metal mesh and foil, specializes in both standard and custom expanded copper products. Our expanded copper micro meshes and foils are known for their high precision and quality, made in the USA with stringent industry certifications (AS9100D & ISO 9001:2015) to ensure reliability. Copper’s exceptional electrical, thermal, and mechanical properties – combined with CThru Metals’ advanced CNC-controlled manufacturing – make expanded copper foil an ideal choice for demanding applications in aerospace, electronics, energy, and more.

Why Use Copper for Expanded Metal Mesh?

Copper (particularly C110 grade copper) offers remarkable material advantages that set it apart. C110 copper is 99.9% pure copper, renowned for its outstanding conductivity (approximately 100% IACS electrical conductivity and excellent heat conduction). It is also inherently corrosion-resistant, forming a protective patina over time that guards against oxidation.

Mechanically, copper is very malleable and ductile, allowing ultra-thin foils to be formed without cracking. These traits – high conductivity, corrosion resistance, and ease of forming – make expanded copper mesh a sought-after solution for electrical and thermal applications. In the following sections, we’ll explore why copper is an excellent choice for expanded metal mesh, common uses of expanded copper foil, and the specific product options and custom services CThru Metals provides.

Copper’s unique combination of material properties makes it one of the best metals for expanded meshes and foils. C110 copper, used in CThru’s expanded copper products, exemplifies these benefits with its purity and performance characteristics. Key benefits of copper expanded metal mesh include:

Excellent Conductivity:

Copper has an electrical conductivity of about 101% IACS (International Annealed Copper Standard) and high thermal conductivity. This means copper expanded metal efficiently carries electric current and heat. In EMI shielding or battery applications, the superior conductivity of copper mesh ensures effective signal attenuation and thermal dissipation.

Corrosion Resistance:

Copper naturally resists corrosion and wear. It does not rust like ferrous metals; instead, it forms a stable oxide layer (patina) that protects the underlying metal. This corrosion resistance makes copper mesh durable in outdoor or harsh environments (for example, in filters or lightning strike protection on aircraft).

Flexible & Lightweight:

In foil form, copper can be produced extremely thin (down to ~25 microns with CThru Metals) while still maintaining mesh integrity. An expanded copper micro mesh is very lightweight – ideal for weight-sensitive uses in industries like aerospace – and the mesh remains flexible due to copper’s ductility. This flexibility eases installation (the mesh can contour to shapes or be rolled) and allows for tight folding or forming without cracking.

Non-Magnetic & Malleable:

Copper is a non-ferrous, non-magnetic metal, so it won’t interfere with sensitive electronic components or magnetic fields. It’s also highly malleable (easily bent or formed) and can be expanded into fine patterns without becoming brittle. The combination of being non-magnetic and easy to form makes copper expanded metal mesh especially useful for electromagnetic shielding enclosures and for forming custom shapes.

Recyclable and Sustainable:

Copper is 100% recyclable and can be reused indefinitely without loss of performance. Using copper expanded metal supports sustainability goals – the material can be reclaimed and recycled, and the expanding process itself generates very little waste compared to perforating sheets. In fact, expanded metal utilizes almost the entire sheet, making it an eco-friendly choice.

These properties explain why copper expanded metal mesh is so popular in applications requiring conductivity. CThru Metals uses C110 copper for its expanded mesh products in lightning strike protection, battery electrode materials, and fuel cells, ensuring you get the full benefit of copper’s conductivity and strength, along with the high precision of our expanding process that keeps the material ultra lightweight.

Common Applications for Expanded Copper Mesh & Foil

Copper expanded metal foils and meshes are used across a wide range of industries. Thanks to their lightweight strength, conductivity, and open-area design, expanded copper mesh solutions are found in many innovative applications. Some of the most common uses include:

Lightning Strike Protection

One of the primary uses of expanded copper foil is in lightning strike protection (LSP) for aircraft, wind turbines, and other composite structures. A fine copper expanded mesh (often called Expanded Copper Foil or Expanded Copper LSP mesh) is embedded at the surface of composite wings, uselages, and blades. Because copper is highly conductive, this mesh safely disperses the immense energy of a lightning strike across the structure’s surface, preventing localized damage. Copper expanded foils for lightning strike protection are extremely lightweight and meet aerospace specifications for conductivity, weight per area, and open area. By using expanded copper rather than a solid foil, the structure is protected without adding significant weight or compromising the composite’s properties.

Battery & Energy Storage

Expanded copper foil plays a key role in advanced batteries and fuel cells. In lithium-ion batteries and other energy storage devices, micro-expanded copper foil is commonly used as a current collector (for the anode) because of its superb electrical conductivity and lightweight form. It can also act as a substrate for coating active battery materials or as a catalyst support in fuel cells. Copper’s ability to be produced in ultra-thin, high-surface-area mesh makes it invaluable for maximizing energy density and improving electrode performance in batteries, supercapacitors, and other energy devices.

EMI/RFI Shielding

Copper expanded metal mesh is an excellent material for electromagnetic interference (EMI) and radio-frequency interference (RFI) shielding. Thin copper mesh foils (often nickel- or tin-plated) are integrated into electronic housings, cable wraps, gaskets, and Faraday cages to block unwanted electromagnetic signals. The high electrical conductivity of copper effectively attenuates interfering signals, protecting sensitive electronics in aerospace, medical, and telecom systems.

Filtration

Expanded copper foil is used in filtration systems as both filter media and support mesh. The mesh’s controlled open area allows fluid or air flow while trapping particles, and its rigidity supports filter elements. Copper’s corrosion resistance suits it for industrial filters (for oil, chemicals, etc.) and automotive filters. For example, expanded metal mesh often serves as the support structure in oil and hydraulic filters, providing strength without impeding flow. Copper mesh can also be found in EMI shielding air filters and microwave oven filters where electrical conductivity is a plus.

CThru Metals has deep experience supplying copper expanded metal for all these applications and can help you select the right mesh for your project.

CThru Mesh™ Standard Copper Expanded Metal Mesh Specifications

CThru Metals offers a range of standard copper expanded metal mesh products under our CThru Mesh™ line. These standard meshes are made from C110 copper foil and are available in various thicknesses and mesh patterns (defined by LWD, strand width, open area, etc.). Below is a table of our standard expanded copper foil specifications. If you have an existing expanded foil spec you’re using, you can likely find an equivalent CThru Mesh™ part in our lineup – and if not, we can customize one for you. All dimensions are available in both metric and imperial units, and custom specs are available upon request.

CThru Mesh™	Original Material & Thickness, mm (inches)	Weight g/Sq. M (Lb/Sq. Ft)	LWD, mm (inches)	Final Thickness, Mm (inches)	Open Area
CU110-2-4-100	110 Copper 0.050 (0.002”)	73 (0.015)	2.50 (0.100”)	0.100 (0.004”)	84%
CU110-2-4-100-F	110 Copper 0.050 (0.002”)	73 (0.015)	2.50 (0.100”)	0.050 (0.002”)	84%
CU110-2-6-100	110 Copper 0.050 (0.002”)	107 (0.022)	2.50 (0.100”)	0.127 (0.005”)	76%
CU110-2-6-100-F	110 Copper 0.050 (0.002”)	107 (0.022)	2.50 (0.100”)	0.050 (0.002”)	76%
CU110-3-7-125	110 Copper 0.075 (0.003”)	142 (0.029)	3.20 (0.125”)	0.127 (0.005”)	79%
CU110-3-7-125-F	110 Copper 0.075 (0.003”)	142 (0.029)	3.20 (0.125”)	0.075 (0.003”)	79%
CU110-3-7-100	110 Copper 0.075 (0.003”)	195 (0.040)	2.50 (0.100”)	0.127 (0.005”)	70%
CU110-3-7-100-F	110 Copper 0.075 (0.003”)	195 (0.040)	2.50 (0.100”)	0.075 (0.003”)	70%

All the above standard meshes are produced from C110 (110 ETP) copper foil. ‘F’ suffix indicates flattened mesh (rolled after expansion for a smooth, flat sheet), whereas non-‘F’ parts are supplied in the standard (raised) expanded form. Custom configurations are also available – if you need a different strand width, opening size, or thickness, we can design a mesh to match your requirements exactly, with no new tooling needed.

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Custom Expanded Metal Foil Solutions from CThru Metals

Superior Customer Service & Custom Engineering Support: While we offer standard products, CThru Metals truly shines in creating custom expanded metal foil solutions. Whether you need a specialized copper mesh for a one-of-a-kind application or want to tweak an existing pattern, our engineering team is ready to assist. Our team’s deep industry knowledge (backed by over 30 years in metal forming and engineering) gives us the insight to tackle unique challenges – whether it’s achieving a specific conductivity/weight ratio or developing a mesh for a cutting-edge technology. We pride ourselves on being more than a supplier; we’re a collaborative partner in your product development process, helping turn your design ideas into a high-quality expanded copper material.
Fully Customizable Mesh Designs: Our engineers can tailor every aspect of the mesh to meet your exact design needs – from strand width and open area to material type and thickness. We leverage decades of manufacturing expertise to advise on the best copper alloy or temper for your project, and we can produce expanded meshes in virtually any configuration. This means you get a copper expanded metal product optimized for your specific performance requirements, rather than a one-size-fits-all solution.
Advanced, Proprietary Manufacturing Equipment: CThru Metals has invested in proprietary, CNC-controlled expanding machines and precision tooling to manufacture expanded foils with unparalleled accuracy. Our advanced equipment can handle ultra-thin copper foils (down to ~0.001″ thick) and produce intricate micro-mesh patterns to very tight tolerances. Because our process is digitally controlled (rather than relying on fixed-size mechanical dies), no custom tooling is required to create new mesh patterns. We can quickly program and adjust parameters to match a competitor’s mesh or develop a brand-new pattern – saving you time and upfront costs. In fact, switching to CThru Mesh™ is seamless: provide us the specifications of your current expanded copper foil (dimensions, pattern, weight, etc.) and we will manufacture a drop-in replacement.
Uncompromising Quality & Consistency: Quality assurance is at the core of our custom manufacturing. CThru Metals operates under rigorous AS9100D aerospace-quality and ISO 9001:2015 certified processes, so you can trust that every expanded copper mesh will meet the highest standards for consistency and performance. We design and build our expanding equipment in-house and maintain complete control over production from start to finish. This vertically integrated approach yields excellent precision and repeatability in the mesh, and also means we can deliver fast turnaround times even on custom orders.

Contact Us to Discuss Your Copper Expanded Metal Needs

Ready to explore how expanded copper foil can improve your product or project? Contact CThru Metals today to request a quote or get more information. Our experts will gladly work with you to identify the right copper expanded metal mesh for your needs, provide samples, or engineer a custom solution. Let’s collaborate to put the power of copper expanded metal to work for you.