Comparison of Material Properties and Selection Guide for Copper and Brass Fuse Contacts

The conductive contact components of various fuses directly determine the stability of current-carrying capacity within the circuit. Copper caps serve as the standard conductive terminal structure for cylindrical fuses; the choice of contact material-whether pure copper or brass-significantly alters the device's overall performance across dimensions such as conductivity, wear resistance, and cost. Fuse contacts must handle the continuous conduction and interruption of high-voltage DC and high-current AC; the material's inherent conductivity, hardness, and oxidation resistance directly impact the fuse's temperature rise, service life, and fault protection reliability. Applications in sectors such as new energy, industrial power distribution, and photovoltaics require the selection of the appropriate contact material based on specific operating conditions. As the two base metals differ in composition-pure copper contains no zinc, whereas brass is a copper-zinc alloy-their distinct inherent properties make them suitable for vastly different circuit applications, a factor that is a critical consideration during the fuse's structural design phase.

1.Conductivity and Temperature Rise Performance

As a high-purity copper material, oxygen-free copper (often referred to as "red copper") offers outstanding conductivity-exceeding 57 MS/m-and extremely low internal resistance, resulting in minimal heat loss during high-current transmission. When integrated with a copper end cap designed for new energy fuses, the assembly ensures lower temperature rise during long-term, full-load operation in high-voltage circuits, effectively preventing contact overheating and oxidation. In contrast, the zinc content in brass reduces overall conductivity; under identical current ratings, brass contacts generate more heat, making the material unsuitable for continuous, high-current applications.

2.Mechanical Wear Resistance and Structural Strength

Brass-a copper-zinc alloy-possesses superior hardness and resistance to deformation and wear compared to the softer oxygen-free copper. It is better suited for scenarios involving frequent insertion/removal during maintenance or environments with intense cabinet vibration. Contact terminals made of brass are less prone to deformation from crimping or surface indentation, maintaining a tight electrical connection even after repeated disassembly and reassembly. Oxygen-free copper contacts, however, are susceptible to permanent deformation under stress; frequent handling can gradually increase contact resistance, creating potential safety hazards related to overheating.

3.Corrosion Resistance and Overall Cost

Oxygen-free copper offers superior natural resistance to oxidation and corrosion, ensuring a longer service life in humid outdoor environments or areas with high salt-spray exposure. Brass is prone to forming an oxidation layer in humid conditions, which impairs conductivity. Regarding production costs, brass raw material is less expensive, allowing for effective cost control in the mass production of industrial fuses. Oxygen-free copper carries a higher unit price and is typically reserved for high-end fuse products that demand exceptional conductivity.

Circuit designs allow for the selection of contact base materials based on specific power requirements. For applications demanding low power loss-such as high-current energy storage systems and automotive high-voltage fuses-Copper Outer Cap are preferred, often paired with integrated pure copper terminals to minimize circuit losses. Conversely, for equipment requiring frequent maintenance or plug-and-play operations-such as combiner boxes and low-voltage distribution cabinets-brass contacts may be selected to enhance wear resistance and service life. When operating conditions simultaneously require high electrical conductivity, high elasticity, and high-temperature resistance, phosphor bronze serves as a balanced alternative, compensating for the insufficient hardness of pure copper and the relatively lower conductivity of brass. Properly matching the copper material for contacts balances operational safety with overall manufacturing costs, ensuring the long-term, stable performance of fuses across various voltage and current ratings.

If you require solutions for matching copper or brass fuse contact terminals to specific operating conditions-such as those found in photovoltaics, automotive applications, or industrial power distribution-please feel free to contact us for guidance on material selection and technical specifications for associated processing.