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Precious Metal AgSnO2In2O3 92/8 EXT

Grade

Choose for low contact resistance and low temperature rise in small relays with moderate arcing duty.

High cost $$$$

Values for the 92/8 EXT condition

Other AgSnO2In2O3 tempers and conditions

AgSnO2In2O3 is listed in 6 conditions; see the grade overview at AgSnO2In2O3.

Compare all 6 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
AgSnO2In2O3 90/10
Use for riveting, heavy upsetting or cold forming of tips where ductility is needed before final work hardening.1102102066 HB68 % IACS
P/M pressed–sintered–repressed compact
Net-shape sintered tips for larger contactor blocks where extrusion of a billet is uneconomic.170240680 HB62 % IACS
92/8 EXTThis page
AgSnO2In2O3 92/8
Choose for low contact resistance and low temperature rise in small relays with moderate arcing duty.1802551282 HV72 % IACS
90/10 EXTDefault
AgSnO2In2O3 90/10
The everyday balance of arc erosion resistance, conductivity and workability for relay and contactor tips.205280995 HV66 % IACS
AgSnO2In2O3 88/12
Pick when weld resistance and erosion life under high make currents matter more than temperature rise.2253007105 HV60 % IACS
AgSnO2In2O3
Internally oxidised route gives an ultrafine oxide dispersion, higher hardness and lower contact resistance for demanding AC contactors.2403106104 HB68 % IACS

What is AgSnO2In2O3 92/8 EXT?

AgSnO2In2O3 92/8 EXT is AgSnO2In2O3 in the 92/8 EXT grade — choose for low contact resistance and low temperature rise in small relays with moderate arcing duty. AgSnO2In2O3 92/8 EXT has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 255 MPa (37 ksi) — weaker than 59% of precious metal grades. Elongation at break is 12% and the elastic modulus is 88 GPa (12.8 Msi). AgSnO2In2O3 92/8 EXT has a density of 10.08 g/cm³ (0.364 lb/in³), lighter than 63% of precious metal grades. It melts at 960°C (1,760 °F). 90/10 EXT is the default condition FabDigit quotes; 92/8 EXT is available on request or by drawing note.

Advantages

  • Conducts heat well — 340 W/m·K (196.4 BTU/hr·ft·°F), better than 86% of precious metal grades
  • High electrical conductivity — 72 % IACS, better than 77% of precious metal grades

Limitations

  • Hard to polish — 60/100, worse than 92% of precious metal grades
  • Limited formability — 55/100, worse than 89% of precious metal grades
  • Limited ductility — 12%, worse than 88% of precious metal grades

AgSnO2In2O3 92/8 EXT properties

Typical room-temperature values for AgSnO2In2O3 92/8 EXT; 10 are specific to this condition. Other listed values are AgSnO2In2O3 reference data and may not represent this condition. Bars are the position among precious metal grades.

Physical3

AgSnO2In2O3 92/8 EXT has a density of 10.08 g/cm³ (0.364 lb/in³), lighter than 63% of precious metal grades. It melts at 960°C (1,760 °F).

Density10.08 g/cm³0.36 lb/in³
Melting Point (Solidus)960°C1,760 °F
Liquidus Temperature962°C1,764 °F

Mechanical10

AgSnO2In2O3 92/8 EXT has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 255 MPa (37 ksi) — weaker than 59% of precious metal grades. Elongation at break is 12% and the elastic modulus is 88 GPa (12.8 Msi).

Elastic (Young's) Modulus88 GPa12.8 Msi
Shear Modulus32 GPa4.6 Msi
Bulk Modulus104 GPa15.1 Msi
Poisson's Ratio0.37
Tensile Strength (Ultimate)255 MPa37 ksi
Yield Strength (0.2% offset)180 MPa26.1 ksi
Elongation at Break12%
Shear Strength175 MPa25.4 ksi
Hardness, Brinell90 HB
Hardness, Vickers82 HV

Thermal6

AgSnO2In2O3 92/8 EXT is rated for continuous service to 250°C (482 °F). It conducts heat at 340 W/m·K (196.4 BTU/hr·ft·°F), better than 86% of precious metal grades. Thermal expansion is 17.5 µm/m·K (9.72 µin/in·°F).

Thermal Conductivity340 W/m·K196 BTU/hr·ft·°F
Specific Heat Capacity240 J/kg·K0.06 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)17.5 µm/m·K9.7 µin/in·°F
Latent Heat of Fusion95 J/g40.8 BTU/lb
Max Service Temperature (continuous)250°C482 °F
Min Service Temperature-60°C-76 °F

Electrical3

AgSnO2In2O3 92/8 EXT conducts electricity at 72 % IACS, better than 77% of precious metal grades.

Electrical Conductivity72 % IACS
Electrical Resistivity2.39×10⁻⁸ Ω·m0.941 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is excellent (85/100), better than 61% of precious metal grades.

Galvanic Potential (seawater, vs SCE)0.1 V
Corrosion ResistanceExcellent85/100
Chemical Resistance SummaryResistant to water, most acids in the absence of oxidisers and to atmospheric oxidation; attacked by nitric acid, hot concentrated sulphuric acid, cyanides and halogens; forms Ag2S tarnish films in sulphur-bearing atmospheres, which are usually broken through by arcing.

Sustainability4

Producing a kilogram of AgSnO2In2O3 92/8 EXT takes about 1,500 MJ of energy and emits 130 kg of CO₂ — more than 51% of precious metal grades. Typical recycled content is 40%.

Embodied Energy (primary production)1,500 MJ/kg644,885 BTU/lb
Embodied Carbon (primary production)130 kg CO₂/kg
Embodied Water25,000 L/kg2,996 gal/lb
Typical Recycled Content40%

Manufacturability6

AgSnO2In2O3 92/8 EXT's machinability is fair (45/100, better than 59% of precious metal grades); weldability poor (30/100); formability good (55/100).

MachinabilityFair45/100
WeldabilityPoor30/100
Formability (cold)Good55/100
Brazeability / SolderabilityGood55/100
PolishabilityGood60/100
Anodizing Responsen/a — not an anodisable alloy; contacts are used bare or with an Ag/AgNi backing layer

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with AgSnO2In2O3 92/8 EXT

Is AgSnO2In2O3 easy to machine?

Machinable with sharp carbide or PCD tooling and generous coolant; the SnO2/In2O3 dispersion is abrasive while the Ag matrix smears, so light finishing cuts and frequent edge changes are needed.

Can AgSnO2In2O3 be welded?

Not fusion welded — tips are resistance-welded or induction/torch brazed through a fine-silver or AgCu backing layer using Ag-Cu-P or BAg filler at low heat input.

Can AgSnO2In2O3 be formed, bent or molded?

Supplied as extruded wire/strip from sintered billets; cold heading, upsetting and profile rolling are routine, but deep drawing and sharp bends are limited by the low elongation of high-oxide grades.

What surface finishes work on AgSnO2In2O3?

Used bare; contact faces are coined or turned rather than plated, and any tarnish film is normally cleared by the first arcing operations.

AgSnO2In2O3 chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
SnO2dispersed oxide phase; 8 wt% for the 90/10 default6 – 138
In2O3wetting/sintering modifier, sometimes with traces of Bi2O3 or CuO1 – 42
Ag≥ 99.95 % purity silver matrixbalance—

AgSnO2In2O3 92/8 EXT — frequently asked

What is AgSnO2In2O3 92/8 EXT used for?

AgSnO2In2O3 92/8 EXT is typically used for automotive relays, low-voltage circuit breakers, contactors and AC/DC power relays. In short: cadmium-free Ag-CdO replacement; low contact resistance oxide grade; abrasive to cutting tools.

What is the yield strength of AgSnO2In2O3 92/8 EXT?

AgSnO2In2O3 92/8 EXT has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 255 MPa (37 ksi) — weaker than 59% of precious metal grades. Strength varies by condition: see the 6 listed tempers.

Is AgSnO2In2O3 92/8 EXT easy to machine?

Reasonably — machinability is rated fair (45/100, better than 59% of precious metal grades). Machinable with sharp carbide or PCD tooling and generous coolant; the SnO2/In2O3 dispersion is abrasive while the Ag matrix smears, so light finishing cuts and frequent edge changes are needed.

Can AgSnO2In2O3 92/8 EXT be welded?

Not readily — weldability is rated poor (30/100). Not fusion welded — tips are resistance-welded or induction/torch brazed through a fine-silver or AgCu backing layer using Ag-Cu-P or BAg filler at low heat input.

What surface finishes work on AgSnO2In2O3 92/8 EXT?

Used bare; contact faces are coined or turned rather than plated, and any tarnish film is normally cleared by the first arcing operations.

Can AgSnO2In2O3 92/8 EXT be formed, bent or molded?

Supplied as extruded wire/strip from sintered billets; cold heading, upsetting and profile rolling are routine, but deep drawing and sharp bends are limited by the low elongation of high-oxide grades.

What is the maximum service temperature of AgSnO2In2O3 92/8 EXT?

AgSnO2In2O3 92/8 EXT is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between AgSnO2In2O3 90/10 EXT and AgSnO2In2O3-IO?

90/10 EXT is the default condition — the everyday balance of arc erosion resistance, conductivity and workability for relay and contactor tips. IO: internally oxidised route gives an ultrafine oxide dispersion, higher hardness and lower contact resistance for demanding AC contactors. Yield strength is 205 MPa in 90/10 EXT versus 240 MPa in IO.

Sources

  1. Data Book of Electrical Contacts — DODUCO / AMI Doduco (2012)
  2. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (electrical contact materials) — ASM International (1990)
  3. Silver metal oxide contact materials product data — Metalor Technologies (2022)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.