Precious Metal 88Ag-12SnO2-H (Hardened)
Heat-treated state · default condition
ASTM B735
Standard stock condition for AgSnO2 wire, profile and strip used to stamp or weld contact tips.
Values for the H condition
Other 88Ag-12SnO2 tempers and conditions
88Ag-12SnO2 is listed in 4 conditions; see the grade overview at 88Ag-12SnO2.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
soft (recrystallised, typ. 550–650 °C) | Pick for rivets, deep-drawn cups and contact tips that must be cold-headed, riveted or heavily formed. | 150 | 235 | 20 | 67 HB | 80 % IACS |
Half hard | Compromise condition for stamped contact strip that still needs moderate bending. | 200 | 270 | 13 | 81 HB | 79 % IACS |
pressed, sintered and repressed contact tips (as-sintered) | Net-shape sintered tips with slight residual porosity; chosen for large contactor contacts brazed to Cu carriers. | — | 220 | 6 | 76 HB | 72 % IACS |
HDefaultThis page Hardened | Standard stock condition for AgSnO2 wire, profile and strip used to stamp or weld contact tips. | 250 | 300 | 8 | 95 HB | 78 % IACS |
What is 88Ag-12SnO2-H?
88Ag-12SnO2-H is 88Ag-12SnO2 heat treated to H — standard stock condition for AgSnO2 wire, profile and strip used to stamp or weld contact tips. 88Ag-12SnO2-H has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 300 MPa (43.5 ksi) — stronger than 81% of precious metal grades. Elongation at break is 8% and the elastic modulus is 88 GPa (12.8 Msi). 88Ag-12SnO2-H has a density of 9.9 g/cm³ (0.358 lb/in³), lighter than 70% of precious metal grades. It melts at 961°C (1,762 °F).
Advantages
- High strength — 250 MPa (36.3 ksi), better than 81% of precious metal grades
- Conducts heat well — 320 W/m·K (184.9 BTU/hr·ft·°F), better than 80% of precious metal grades
- High electrical conductivity — 78 % IACS, better than 79% of precious metal grades
Limitations
- Limited ductility — 8%, worse than 92% of precious metal grades
- Limited formability — 35/100, worse than 92% of precious metal grades
- Hard to polish — 65/100, worse than 87% of precious metal grades
88Ag-12SnO2-H properties
Typical room-temperature values for 88Ag-12SnO2-H; 15 are specific to this condition. Other listed values are 88Ag-12SnO2 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
88Ag-12SnO2-H has a density of 9.9 g/cm³ (0.358 lb/in³), lighter than 70% of precious metal grades. It melts at 961°C (1,762 °F).
Mechanical9
88Ag-12SnO2-H has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 300 MPa (43.5 ksi) — stronger than 81% of precious metal grades. Elongation at break is 8% and the elastic modulus is 88 GPa (12.8 Msi).
Thermal6
88Ag-12SnO2-H is rated for continuous service to 250°C (482 °F). It conducts heat at 320 W/m·K (184.9 BTU/hr·ft·°F), better than 80% of precious metal grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
88Ag-12SnO2-H conducts electricity at 78 % IACS, better than 79% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (80/100), worse than 52% of precious metal grades.
Sustainability4
Producing a kilogram of 88Ag-12SnO2-H takes about 1,300 MJ of energy and emits 100 kg of CO₂ — less than 61% of precious metal grades. Typical recycled content is 40%.
Manufacturability8
88Ag-12SnO2-H's machinability is fair (40/100, worse than 60% of precious metal grades); weldability good (55/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 88Ag-12SnO2-H
Is 88Ag-12SnO2 easy to machine?
Turns and stamps like soft silver but is gummy and the SnO2 is mildly abrasive — use sharp carbide/PCD tools, high speed, light feed and oil mist; keep all chips for refining.
Can 88Ag-12SnO2 be welded?
Not fusion welded as a structural alloy; tips are resistance-welded, laser-welded or Ag-brazed (BAg-1/Cd-free) to Cu or CuZn carriers, often through a fine-silver backing layer.
Can 88Ag-12SnO2 be formed, bent or molded?
Supplied hot-extruded then cold drawn/rolled; anneal at ~550–650 °C before cold heading, riveting or deep drawing, and expect lower cold ductility than AgCdO or AgNi.
What surface finishes work on 88Ag-12SnO2?
Used bare — the arc keeps the surface clean; do not plate the contact face. Ag or Ag-braze backing improves solderability; degrease and store away from H2S to limit tarnish.
88Ag-12SnO2 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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| SnO2tin(IV) oxide dispersoid, ≈17 vol% | 11 – 13 | 12 |
| In2O3optional wetting/dopant additive in some grades (also Bi2O3, WO3, CuO, MoO3) | 0 – 1 | — |
| CdRoHS-relevant residual; grade is cadmium-free by definition | 0 – 0.01 | — |
| Agnominal 88 %, purity of matrix ≥99.9 % | balance | — |
88Ag-12SnO2-H — frequently asked
What is 88Ag-12SnO2-H used for?
88Ag-12SnO2-H is typically used for contactors, circuit breakers and automotive relays. In short: cadmium-free AgCdO replacement; best arc-erosion AgSnO2; low cold ductility.
What is the yield strength of 88Ag-12SnO2-H?
88Ag-12SnO2-H has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 300 MPa (43.5 ksi) — stronger than 81% of precious metal grades. Strength varies by condition: see the 4 listed tempers.
Is 88Ag-12SnO2-H easy to machine?
Not especially — machinability is rated fair (40/100, worse than 60% of precious metal grades). Turns and stamps like soft silver but is gummy and the SnO2 is mildly abrasive — use sharp carbide/PCD tools, high speed, light feed and oil mist; keep all chips for refining.
Can 88Ag-12SnO2-H be welded?
Yes — weldability is rated good (55/100). Not fusion welded as a structural alloy; tips are resistance-welded, laser-welded or Ag-brazed (BAg-1/Cd-free) to Cu or CuZn carriers, often through a fine-silver backing layer.
What surface finishes work on 88Ag-12SnO2-H?
Used bare — the arc keeps the surface clean; do not plate the contact face. Ag or Ag-braze backing improves solderability; degrease and store away from H2S to limit tarnish.
Can 88Ag-12SnO2-H be formed, bent or molded?
Supplied hot-extruded then cold drawn/rolled; anneal at ~550–650 °C before cold heading, riveting or deep drawing, and expect lower cold ductility than AgCdO or AgNi.
What is the maximum service temperature of 88Ag-12SnO2-H?
88Ag-12SnO2-H 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.
Sources
- Data Book of Electrical Contacts (AgSnO2 contact materials) — Doduco / AMI Doduco (2012)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Electrical Contact Materials) — ASM International (1990)
- Silver tin oxide contact material datasheets (AgSnO2 10/12/14) — Metalor / Umicore / Materion (2022)
- IEC 60947-4-1 contactor duty and contact material practice — IEC (2018)
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.