Contact Wire Materials
In the instant electricity makes and breaks, the material decides everything.
Overview
LT Metal's contact materials draw on 30 years of accumulated know-how and the continuous development of new materials, delivering customer satisfaction through good workability and a reliable supply of material.
Classification by material
Classification by Material
Pt Group
Pt Group
Suited to applications with low contact force where reliability is the primary concern. It does not oxidize or discolor at any temperature.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| Pt | 99.99 | 40 | 1769 | 17 | 21.45 | 0.17 | Telephones, relays, precision measuring instruments, railway signaling |
Pt-Ir Group
It has a strong arc-extinguishing capability and its contact resistance does not change. Hardness increases as the iridium content rises, and it does not discolor at all. It is suitable for high-speed, high-sensitivity applications operating under high contact force.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| Pt-Ir10 | Pt90-Ir10 | 126 | 1780 | 7.0 | 21.6 | 0.074 | Ignition magnetos, high-sensitivity relays, governors for micro motors, thermostats, induction regulators, alarm devices |
| Pt-Ir30 | Pt70-Ir30 | 285 | 1885 | 5.3 | 21.8 | 0.037 |
Au Group
Au
Its low electrical resistance and high corrosion resistance prevent surface discoloration and oxide formation — whether it is used as a light-load contact that sits idle for long periods or operates only intermittently, or as plating over silver contacts for wireless applications.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| Au | 99.99 | 20 | 1063 | 71 | 19.3 | 0.7 | Communication connectors, brushes, plugs, commutator sockets |
Au Group
Used as a substitute for platinum in high-sensitivity devices. Its resistance to electrical erosion is lower, but it offers better welding resistance and hardness than silver.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| AuAg90 | Au10Ag90 | 29 | 965 | 48 | 11.0 | 0.47 | Slip ring brushes, DC signaling devices, telecom circuit breakers, switchboards |
| AuAg30 | Au10Ag30 | 32 | 1025 | 16 | 16.6 | 0.16 |
Excellent corrosion resistance, low contact resistance and a long service life make it highly reliable. It is also known as PGS.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| AuAgPt | – | 60 | 1100 | 11.0 | 17.1 | 0.12 | Heavy-current telecom devices, controllers |
Offers excellent corrosion resistance together with excellent mechanical properties.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| AuNi5 | Au95Ni5 | 120 | 1020 | 12.9 | 18.3 | – | Heavy-duty telecom contacts |
An alloy containing 62.5% gold, produced in wire or strip form. It withstands impact contact well, has good spring properties and does not discolor at all.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| AuAgCu | Au62.5 Ag30 Cu7.5 | 165 | 861 | 12.0 | 13.7 | 0.13 | – |
Pd Group
Pd Group
A convenient material that can substitute for platinum under suitable conditions, though its resistance to electrical erosion is slightly lower. It has good arc resistance and excellent resistance to oxidation and sulfidation.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| Au | 99.99 | 20 | 1063 | 71 | 19.3 | 0.7 | Communication connectors, brushes, plugs, commutator sockets |
AgPd Group
It is completely resistant to the formation of sulfide films. At a silver content of 40% it reaches maximum hardness and wear resistance, and it is used as a substitute for platinum.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| AgPd30 | Ag70Pd30 | 60 | 1225 | 11.5 | 10.9 | 0.11 | Automotive fuel gauges, sliding contact material for telephone relays, signaling devices, commutator brushes, thermostats (small DC), industrial instruments |
| AgPd40 | Ag60Pd40 | 65 | 1290 | 8.2 | 11.1 | 0.1 | |
| AgPd50 | Ag50Pd50 | 75 | 1350 | 5.7 | 11.2 | 0.06 | |
| AgPd60 | Ag40Pd60 | 80 | 1395 | 4.3 | 11.4 | 0.07 | |
| AgPd70 | Ag30Pd70 | 90 | 1430 | 4.3 | 11.5 | – |
Ag Group
Ag Group
Silver has the highest electrical and thermal conductivity of any metal, does not oxidize, and maintains low contact resistance even under low contact force. It cannot be used where the air contains sulfur, which forms a sulfide film on the surface.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| Ag | 99.99 | 26 | 960 | 106 | 10.5 | 1.0 | Communication contacts, thermostats, micro relays, rotary switches, telephones, small breakers, home appliance switches |
| AgF | Ag99.93Cu0.07 | 28 | 960 | 106 | 10.5 | – | |
| AgS | Ag99.97Cu0.03 | 28 | 960 | 106 | 10.5 | – | |
| AgH | Ag99.97Ni0.03 | 28 | 960 | 106 | 10.5 | – | |
| AgNi0.15 | Ag99.85Ni0.15 | 30 | 960 | 106 | 10.5 | – | |
| AgNi0.2 | Ag99.80Ni0.20 | 30 | 960 | 106 | 10.5 | – |
AgNi Group
AgNi Group
AgNi alloy is a contact material that improves the welding resistance and wear resistance of silver while enhancing workability. Because nickel has very limited solubility in silver, it is produced by powder metallurgy, and a nickel content of 5 to 20 wt% is most commonly used.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| AgH | Ag99.97Ni0.03 | 35 | 960.5 | 106 | 10.5 | 1.0 | DC sliding contacts, rotary switches, home appliance breakers, appliance wiring switches, circuit breaker switches, relays, push-buttons |
| AgNi0.2 | Ag99.8Ni0.2 | 40 | 960.5 | 106 | 10.5 | 1.0 | |
| AgNi10 | Ag90Ni10 | 65 | 960.5 | 91 | 10.3 | – | |
| AgNi15 | Ag85Ni15 | 73 | 960.5 | 88 | 10.3 | – | |
| AgNi20 | Ag80Ni20 | 80 | 960.5 | 83 | 10.2 | – | |
| AgNi30 | Ag70Ni30 | 60 | 960.5 | 16 | 10.0 | – | |
| AgNi40 | Ag60Ni40 | 80 | 960.5 | 9 | 9.8 | – |
AgCu Group
AgCu Group
As the copper content rises, tarnish resistance decreases while hardness and mechanical wear resistance increase. It cannot be used where contact force is high and sliding contact occurs during operation.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| S97 | Ag97Cu3 | 45 | – | 92 | 10.4 | – | Rotary switches, thermostats, commutator switches, tuners, relays, home appliance switches, vending machines |
| AgCu10 | Ag90Cu10 | 62 | 778 | 86 | 10.3 | 0.80 | |
| AgCu20 | Ag80Cu20 | 85 | 778 | 82 | 10.2 | 0.82 | |
| AgCuNi0.5 | AgCu24.5Ni0.5 | 115 | 810 | 68 | 10.1 | – | |
| AgCu40 | AgCu40 | 95 | 778 | 82 | 9.8 | – |
AgCdO Group
AgCdO Group
AgCdO grades are produced with silver-cadmium oxide as the main constituent. As a contact material it offers excellent welding and wear resistance, stable contact resistance and good electrical and thermal conductivity. It is currently used widely for medium-current contacts.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| HE100 | Ag90CdO10 | 70 | 960.5 | 80 | 10.2 | – | AC relays and switches, home appliance breakers, magnetic switches, no-fuse breakers, motor breakers, heavy-load connectors |
| HE120 | Ag88CdO12 | 70 | 960.5 | 80 | 10.2 | – | |
| HE130 | Ag86.5CdO13.5 | 75 | 960.5 | 78 | 10.1 | – | |
| HE140S | Ag85.3CdO14.7 | 75 | 960.5 | 77 | 10.1 | – | |
| HE181 | Ag82.9CdO+α17.1 | 80 | 960.5 | 75 | 10.0 | – | |
| HE181F | Ag82.9CdO17.1 | 80 | 960.5 | 75 | 10.0 | – |
AgSnO Group (Cd FREE)
AgSnO2 Group (powder metallurgy)
A material in which SnO2 powder is dispersed in a silver matrix by powder metallurgy. It maintains excellent electrical conductivity while improving arc resistance, welding resistance and erosion resistance.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| HFE10S | Ag90MOx10 | 80 | 960.5 | 90 | 10.0 | – | AC switches and relays, home appliance breakers |
| HFE12S | Ag88MOx12 | 90 | 960.5 | 85 | 9.9 | – |
AgSnO2 Group (internal oxidation)
An oxide-dispersion-strengthened silver alloy made by the full oxidation process. SnO2 is thermally stable by nature and is finely distributed in the silver matrix, giving outstanding arc resistance, welding resistance and erosion resistance. It performs particularly well in relays and switches handling medium DC loads.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| HFE90 | Ag91MOx9 | 110 | 960.5 | 73 | 10.0 | – | Automotive relays and switches, heavy-load circuit breakers, power switches, magnetic switches |
| HFE120 | Ag88MOx12 | 115 | 960.5 | 70 | 9.9 | – |
AgSnInOx Group (Cd FREE)
AgSnInOx Group
A cadmium-free material developed to meet environmental requirements. Produced by internal oxidation of an Ag-Sn alloy with several additional alloying elements, it contains very finely dispersed oxide particles, giving excellent welding resistance and erosion resistance. It is used for both AC and DC loads.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| HFE90 | Ag91MOx9 | 110 | 960.5 | 73 | 10.0 | – | Automotive relays and switches, heavy-load circuit breakers, power switches, magnetic switches |
| HFE120 | Ag88MOx12 | 115 | 960.5 | 70 | 9.9 | – | |
| SJ06 | Ag90MOx10 | 100 | 960.5 | 75 | 10.1 | – | General-purpose relays and switches, magnetic switches, AC lamp / motor / resistive loads, molded case circuit breakers, automotive electrical relays |
| SJ23 | Ag87.5MOx12.5 | 105 | 960.5 | 70 | 9.9 | – | |
| SJ25P | Ag85.5MOx14.5 | 95 | 960.5 | 70 | 9.8 | – | |
| SJ160 | Ag84.0MOx16.0 | 105 | 960.5 | 68 | 9.8 | – | |
| EP45 | Ag85.5MOx14.5 | 105 | 960.5 | 70 | 9.8 | – | |
| MS45 | Ag85.5MOx14.5 | 100 | 960.5 | 70 | 9.8 | – |
AgZnO Group
AgZnO Group
A cadmium-free material with no environmental concerns, produced by internal oxidation of an Ag-Zn alloy. Finely dispersed oxide particles improve welding and erosion resistance, making it an alternative to AgCdO. It is used mainly in AC switches and magnetic switches.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| SZ1 | Ag91.0MOx9.0 | 77 | 960.5 | 80 | 10.1 | – | Home appliance switches, magnetic switches |
| SZ2 | Ag90.4MOx9.6 | 80 | 960.5 | 78 | 10.1 | – |
Other
AgCdNi Group
Used as a substitute for the Ag-Cu series. Its tarnish resistance is better than the Ag-Cu series, but its contact resistance is inferior.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| AgCdNi0.5 | Ag97.6CdNi2.4 | 55 | 850 | 80 | 10.3 | 0.24 | Voltage regulators, thermostats, switches, overload control relays |
AgIn Group
It is self-lubricating and is used as a sliding contact under relatively high contact pressure.
| Grade | Composition (wt%) |
Hardness (annealed, Hv) |
Melting Point ℃ (solidus) |
Electrical Conductivity (%IACS) |
Density (g/cm³) |
Thermal Conductivity (Cal/cm·sec·℃) |
Applications |
|---|---|---|---|---|---|---|---|
| AgIn18 | Ag82 In18 | 60 | 730 | – | 9.7 | – | Wipers for type-A switchboards, rotary switches, low-noise switches |