Precious Metal B617
GB B617
ASTM B617 covers a wrought 90Ag-10Cu contact alloy standardised for electrical contact rivets, strip and wire, offering higher hardness and wear resistance than fine silver at slightly reduced conductivity.
Reference datasheet — B617 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
B617 tempers and conditions
B617 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 | Choose for maximum ductility — rivet heading, deep drawing, cold clinching and brazed contact assemblies. | 65 | 265 | 40 | 58 HB | 85 % IACS |
Quarter hard | Light stiffening for flat strip that must stay dead-flat during stamping yet still be formed tightly. | 175 | 300 | 28 | 72 HB | 85 % IACS |
Half hard | General stamping temper: better blanked-edge quality and rivet shank strength with useful remaining ductility. | 240 | 345 | 20 | 86 HB | 84 % IACS |
Full hard | Most common contact-strip temper — balances wear resistance and stamping formability for bifurcated blades and rivets. | 310 | 400 | 10 | 100 HB | 84 % IACS |
Extra hard | Use where contact-force retention and abrasion resistance matter more than tight bending. | 385 | 450 | 6 | 112 HB | 83 % IACS |
Spring hard | Maximum as-rolled hardness for sliding/wiping contacts and thin flat springs with only gentle forming. | 450 | 500 | 3 | 124 HB | 83 % IACS |
What is B617?
ASTM B617 covers a wrought 90Ag-10Cu contact alloy standardised for electrical contact rivets, strip and wire, offering higher hardness and wear resistance than fine silver at slightly reduced conductivity. It is specified where formability and conductivity must both be high: annealed material runs 265 MPa tensile, 65 MPa yield, 40 % elongation, 58 HB, 85 % IACS and 360 W/m·K, with tempers from O through H08 and spring. Practical service is limited to about 200 °C and the surface tarnishes in sulphur-bearing atmospheres, so contacts are usually plated or lacquered. For a lower-melting alloy that can double as a braze filler, see ASTM B628 (72Ag-28Cu). B617 has a density of 10.31 g/cm³ (0.372 lb/in³), lighter than 52% of precious metal grades. It melts at 779°C (1,434 °F). B617 has a yield strength of 65 MPa (9.43 ksi) and a tensile strength of 265 MPa (38.4 ksi) — weaker than 91% of precious metal grades. Elongation at break is 40% and the elastic modulus is 79 GPa (11.5 Msi).
What is B617 used for?
- low-voltage switch contacts
- relay contact rivets
- connector contact tips
Advantages
- Conducts heat well — 360 W/m·K (208 BTU/hr·ft·°F), better than 94% of precious metal grades
- Ductile — tolerates forming and impact — 40%, better than 92% of precious metal grades
- High electrical conductivity — 85 % IACS, better than 88% of precious metal grades
- Easy to machine — 55/100, better than 86% of precious metal grades
- Polishes to a fine finish — 95/100, better than 86% of precious metal grades
Limitations
- Low strength — 65 MPa (9.43 ksi), worse than 91% of precious metal grades
- Limited service temperature — 200°C (392 °F), worse than 89% of precious metal grades
- Low stiffness — 79 GPa (11.5 Msi), worse than 86% of precious metal grades
B617 properties
Typical room-temperature values for B617-O; bars are the position among precious metal grades.
Physical3
B617 has a density of 10.31 g/cm³ (0.372 lb/in³), lighter than 52% of precious metal grades. It melts at 779°C (1,434 °F).
Mechanical12
B617 has a yield strength of 65 MPa (9.43 ksi) and a tensile strength of 265 MPa (38.4 ksi) — weaker than 91% of precious metal grades. Elongation at break is 40% and the elastic modulus is 79 GPa (11.5 Msi).
Thermal6
B617 is rated for continuous service to 200°C (392 °F). It conducts heat at 360 W/m·K (208 BTU/hr·ft·°F), better than 94% of precious metal grades. Thermal expansion is 18.7 µm/m·K (10.4 µin/in·°F).
Electrical3
B617 conducts electricity at 85 % IACS, better than 88% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), worse than 56% of precious metal grades.
Sustainability4
Producing a kilogram of B617 takes about 1,500 MJ of energy and emits 100 kg of CO₂ — more than 51% of precious metal grades. Typical recycled content is 45%.
Manufacturability8
B617's machinability is good (55/100, better than 86% of precious metal grades); weldability good (55/100); formability excellent (92/100).
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. B617 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with B617
Is B617 easy to machine?
Machines cleanly with sharp, high-rake carbide or HSS tools and light oil; soft tempers are gummy and burr — prefer 1/2-hard or harder for turned rivets and collect all chips for refining.
Can B617 be welded?
Joined mainly by resistance/projection welding, laser welding or brazing to Cu/brass carriers; fusion welding is uncommon and requires protection against copper oxidation and gas pickup.
Can B617 be formed, bent or molded?
Annealed strip and wire stamp, head, coin and deep-draw excellently; interanneal at 600–650 °C after ~50 % reduction and quench or cool in a reducing atmosphere to avoid firescale.
B617 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 content per ASTM B617 | 89.5 – 90.5 | 90 |
| Other (total impurities)Pb, Fe, Bi, Sb etc. kept low for workability | ≤ 0.15 | — |
| Cubalance copper | ≥ 9.5 (balance) | — |
What surface finishes work on B617?
Buffs to a mirror; bright-dip or citric/thiourea pickle removes copper firescale; anti-tarnish protection is by Rh, Au or thin Sn/Ni plating or a lacquer — anodizing does not apply.
Equivalent designations
Standards and trade names that resolve to Precious Metal B617 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- 90Ag-10Cu Coin Silver
How much does B617 cost?
B617 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.
B617 — frequently asked
What is B617 used for?
B617 is typically used for low-voltage switch contacts, relay contact rivets and connector contact tips. In short: standardised contact rivet stock; wear-resistant fine-silver substitute; very high formability rating.
What is the yield strength of B617?
B617 has a typical yield strength of 65 MPa (9.43 ksi) and a tensile strength of 265 MPa (38.4 ksi) — weaker than 91% of precious metal grades. Strength varies by condition: see the 6 listed tempers.
Is B617 easy to machine?
Reasonably — machinability is rated good (55/100, better than 86% of precious metal grades). Machines cleanly with sharp, high-rake carbide or HSS tools and light oil; soft tempers are gummy and burr — prefer 1/2-hard or harder for turned rivets and collect all chips for refining.
Can B617 be welded?
Yes — weldability is rated good (55/100). Joined mainly by resistance/projection welding, laser welding or brazing to Cu/brass carriers; fusion welding is uncommon and requires protection against copper oxidation and gas pickup.
What surface finishes work on B617?
Buffs to a mirror; bright-dip or citric/thiourea pickle removes copper firescale; anti-tarnish protection is by Rh, Au or thin Sn/Ni plating or a lacquer — anodizing does not apply.
Can B617 be formed, bent or molded?
Annealed strip and wire stamp, head, coin and deep-draw excellently; interanneal at 600–650 °C after ~50 % reduction and quench or cool in a reducing atmosphere to avoid firescale.
What is the maximum service temperature of B617?
B617 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between B617-O and B617-H08?
O is the default condition — choose for maximum ductility — rivet heading, deep drawing, cold clinching and brazed contact assemblies. H08: maximum as-rolled hardness for sliding/wiping contacts and thin flat springs with only gentle forming. Yield strength is 65 MPa in O versus 450 MPa in H08.
How much does B617 cost?
B617 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 B617 — Standard Specification for Coin Silver Electrical Contact Alloy — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Precious Metals & Electrical Contact Materials) — ASM International (1990)
- ASM Specialty Handbook: Electrical Contact Materials chapter — ASM International (1998)
- Silver-copper contact strip and rivet alloy data (Ag90Cu10) — Deringer-Ney / Metalor / AMI Doduco (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.