Precious Metal 70Ag-30Ni
ASTM B427
70Ag-30Ni is a dispersion-strengthened silver–nickel contact composite to ASTM B427, in which 30% nickel dispersed through the silver matrix resists material transfer and contact welding under arcing.
Reference datasheet — 70Ag-30Ni is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the O condition
70Ag-30Ni tempers and conditions
70Ag-30Ni is supplied in 6 conditions, soft to hard. O is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Default condition: maximum ductility for riveting, stamping, deep drawing and welding of contact buttons onto carriers. | 110 | 260 | 25 | 58 HB | 70 % IACS |
Quarter hard | Pick when slightly stiffer strip is needed for stamping self-supporting contact blades while keeping good bendability. | 230 | 320 | 12 | 75 HB | 69 % IACS |
Half hard | Intermediate temper balancing formability and contact-force stiffness for stamped bridge contacts. | 300 | 360 | 7 | 84 HB | 68 % IACS |
Full hard | Pick for maximum hardness/wear resistance in sliding or lightly formed contact parts where bending is minimal. | 370 | 410 | 3 | 95 HB | 68 % IACS |
Spring temper | Pick for self-springing contact fingers and wiper elements that must supply their own contact force. | 420 | 450 | 2 | 108 HB | 67 % IACS |
Spring hard | Heavily cold-worked spring temper of AgNi30 contact alloy — highest strength and spring-back for contact springs and blades, at the cost of ductility. | 430 | 470 | 2 | 135 HV | 60 % IACS |
Supply forms, finishes and certifications
Ways 70Ag-30Ni is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
AS | As-sintered / extruded | Coating |
What is 70Ag-30Ni?
70Ag-30Ni is a dispersion-strengthened silver–nickel contact composite to ASTM B427, in which 30% nickel dispersed through the silver matrix resists material transfer and contact welding under arcing. Engineers specify it for high-current switchgear where anti-weld behaviour matters more than minimum contact resistance; it is supplied as powder-metallurgy strip, wire, rivets and brazed-on contact buttons in O through H08 and HS tempers. Electrical conductivity is 70% IACS, thermal conductivity 300 W/m·K and maximum service temperature 250 °C, and the bulk alloy is not fusion welded. Where lower contact resistance is required, 85Ag-15Ni and 90Ag-10Ni carry more silver. 70Ag-30Ni has a density of 9.95 g/cm³ (0.359 lb/in³), lighter than 67% of precious metal grades. It melts at 961°C (1,762 °F). 70Ag-30Ni has a yield strength of 110 MPa (16 ksi) and a tensile strength of 260 MPa (37.7 ksi) — weaker than 80% of precious metal grades. Elongation at break is 25% and the elastic modulus is 110 GPa (16 Msi).
What is 70Ag-30Ni used for?
- circuit breaker contacts
- contactor contacts
- high-current relays
Advantages
- Stiff — 110 GPa (16 Msi), better than 76% of precious metal grades
- High electrical conductivity — 70 % IACS, better than 75% of precious metal grades
Limitations
- Low strength — 110 MPa (16 ksi), worse than 80% of precious metal grades
- Hard to polish — 70/100, worse than 76% of precious metal grades
70Ag-30Ni properties
Typical room-temperature values for 70Ag-30Ni-O; bars are the position among precious metal grades.
Physical3
70Ag-30Ni has a density of 9.95 g/cm³ (0.359 lb/in³), lighter than 67% of precious metal grades. It melts at 961°C (1,762 °F).
Mechanical13
70Ag-30Ni has a yield strength of 110 MPa (16 ksi) and a tensile strength of 260 MPa (37.7 ksi) — weaker than 80% of precious metal grades. Elongation at break is 25% and the elastic modulus is 110 GPa (16 Msi).
Thermal5
70Ag-30Ni is rated for continuous service to 250°C (482 °F). It conducts heat at 300 W/m·K (173.3 BTU/hr·ft·°F), better than 74% of precious metal grades. Thermal expansion is 17.5 µm/m·K (9.72 µin/in·°F).
Electrical3
70Ag-30Ni conducts electricity at 70 % IACS, better than 75% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), worse than 66% of precious metal grades.
Sustainability4
Producing a kilogram of 70Ag-30Ni takes about 1,100 MJ of energy and emits 80 kg of CO₂ — less than 71% of precious metal grades. Typical recycled content is 50%.
Manufacturability8
70Ag-30Ni's machinability is fair (45/100, better than 59% of precious metal grades); weldability very good (70/100); formability excellent (85/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the precious metal family
Yield strength against density for every precious metal grade FabDigit runs. 70Ag-30Ni is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 70Ag-30Ni
Is 70Ag-30Ni easy to machine?
Turns and drills but is gummy — use sharp, high-rake carbide, generous coolant and collect all chips as precious-metal scrap; the Ni phase mildly abrades tooling.
Can 70Ag-30Ni be welded?
Normally resistance- or ultrasonic-welded (or Ag-brazed) as contact buttons onto Cu/CuZn carriers; fusion welding of the bulk is not practised because the two phases are immiscible.
Can 70Ag-30Ni be formed, bent or molded?
Made by press-sinter-extrude powder metallurgy then cold rolled/drawn; soft temper rivets and deep-draws easily, intermediate anneals at 600–700 °C restore ductility after ~50 % reduction.
70Ag-30Ni 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 |
|---|---|---|
| Agsilver matrix, fine-silver purity feedstock | 69 – 71 | 70 |
| Other (total impurities)Cu, Fe, O and residual PM binders per ASTM B427 | ≤ 0.15 | |
| Nidispersed nickel particles, typically 1–5 µm | balance |
What surface finishes work on 70Ag-30Ni?
Used bare in most switchgear; optional Ag or hard-Au flash for shelf life and dry-circuit reliability; anti-tarnish passivation recommended for sulphur-containing environments.
Equivalent designations
Standards and trade names that resolve to Precious Metal 70Ag-30Ni in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B427
- Also called
- AgNi30
How much does 70Ag-30Ni cost?
70Ag-30Ni is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
70Ag-30Ni — frequently asked
What is 70Ag-30Ni used for?
70Ag-30Ni is typically used for circuit breaker contacts, contactor contacts and high-current relays. In short: highest Ni content in family; best anti-weld Ag-Ni grade; cadmium-free arcing contact.
What is the yield strength of 70Ag-30Ni?
70Ag-30Ni has a typical yield strength of 110 MPa (16 ksi) and a tensile strength of 260 MPa (37.7 ksi) — weaker than 80% of precious metal grades. Strength varies by condition: see the 6 listed tempers.
Is 70Ag-30Ni easy to machine?
Reasonably — machinability is rated fair (45/100, better than 59% of precious metal grades). Turns and drills but is gummy — use sharp, high-rake carbide, generous coolant and collect all chips as precious-metal scrap; the Ni phase mildly abrades tooling.
Can 70Ag-30Ni be welded?
Yes — weldability is rated very good (70/100). Normally resistance- or ultrasonic-welded (or Ag-brazed) as contact buttons onto Cu/CuZn carriers; fusion welding of the bulk is not practised because the two phases are immiscible.
What surface finishes work on 70Ag-30Ni?
Used bare in most switchgear; optional Ag or hard-Au flash for shelf life and dry-circuit reliability; anti-tarnish passivation recommended for sulphur-containing environments.
Can 70Ag-30Ni be formed, bent or molded?
Made by press-sinter-extrude powder metallurgy then cold rolled/drawn; soft temper rivets and deep-draws easily, intermediate anneals at 600–700 °C restore ductility after ~50 % reduction.
What is the maximum service temperature of 70Ag-30Ni?
70Ag-30Ni 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 70Ag-30Ni-O and 70Ag-30Ni-H08?
O is the default condition — default condition: maximum ductility for riveting, stamping, deep drawing and welding of contact buttons onto carriers. H08: heavily cold-worked spring temper of AgNi30 contact alloy — highest strength and spring-back for contact springs and blades, at the cost of ductility. Yield strength is 110 MPa in O versus 430 MPa in H08.
How much does 70Ag-30Ni cost?
70Ag-30Ni is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B427 — Standard Specification for Silver-Nickel Electrical Contact Material — ASTM International (2021)
- Data Book of Electrical Contacts (AgNi contact materials) — Doduco / AMI Doduco (2012)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- Silver-nickel contact strip and rivet materials — Metalor Technologies / Umicore Contact Materials (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.