Contact materials & finished assemblies

Fine Silver (99.9% Ag)

Pure silver with the highest electrical and thermal conductivity of any contact material. Soft and easily formed, it conducts and dissipates heat beautifully but tends to weld and erode under heavy arcing — so it shines in light-duty switching and as the contact face of overlay buttons.

• Highest conductivity of all contact metals
• Excellent heat dissipation
• Soft, easily worked
• Lower arc-erosion / anti-weld resistance

Best for: Low-current, low-energy switching and overlay contact faces

Silver Cadmium Oxide

The long-established workhorse of the industry. The dispersed cadmium-oxide phase gives outstanding arc-erosion and anti-weld behaviour across a wide current range, with low, stable contact resistance. Note: it contains cadmium and is being phased out under RoHS in many markets — AgSnO₂ is the modern drop-in replacement.

• Excellent arc-erosion resistance
• Strong anti-weld performance
• Low, stable contact resistance
• Wide current range

Best for: Contactors, relays and switches across a broad load range

Silver Tin Oxide

The cadmium-free, RoHS-compliant successor to AgCdO. The tin-oxide dispersion resists welding and material transfer exceptionally well and stands up to DC and high making-current duty, making it the modern default for many contactors and switching devices.

• Cadmium-free / RoHS compliant
• Very high resistance to welding
• Low material transfer
• Strong under DC & high making current

Best for: Modern contactors, switches and DC switching duty

Silver Nickel

A finely, evenly distributed nickel phase delivers low and stable contact resistance, good machinability and excellent resistance to material transfer. Ideal for the lower current ranges found in protective and control devices.

• Low, stable contact resistance
• Good machinability
• Resists material transfer
• Fine, uniform microstructure

Best for: MCBs, relays and auxiliary / control switches at lower currents

Silver Copper Nickel

Silver hardened with small additions of copper and nickel for noticeably higher hardness and resistance to mechanical and sliding wear, while keeping good electrical conductivity. A tough, long-wearing choice for the contact face of overlay buttons and for mechanically stressed sliding contacts.

• Higher hardness, work-hardenable
• Good resistance to mechanical / sliding wear
• Resists material transfer
• Good electrical conductivity

Best for: Hard-wearing overlay faces and mechanically stressed sliding contacts