Precious Metal Coin Silver 900-O (Annealed)
Temper · default condition
Default stocked condition for sheet/wire that will be raised, stamped, bent or die-struck.
Values for the O condition
Other Coin Silver 900 tempers and conditions
Coin Silver 900 is listed in 7 conditions; see the grade overview at Coin Silver 900.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefaultThis page Annealed | Default stocked condition for sheet/wire that will be raised, stamped, bent or die-struck. | 100 | 290 | 40 | 66 HB | 85 % IACS |
As fabricated | Cast jewellery, holloware and medallions before any work hardening; lower ductility due to dendritic structure and porosity. | 115 | 240 | 15 | 64 HB | 82 % IACS |
Quarter hard | Light stiffening while retaining useful bend ductility — bezels, light stampings, coin blanks. | 225 | 345 | 20 | 90 HB | 84 % IACS |
Half hard | General-purpose spring-free stiffness for flatware, findings and machined parts. | 310 | 400 | 10 | 110 HB | 84 % IACS |
Full hard | Maximum practical strength/wear resistance for straight wire, knife handles and contact strip. | 420 | 480 | 4 | 133 HB | 83 % IACS |
Pre-hardened | Precipitation of Cu-rich phase gives the highest hardness without cold work — for wear surfaces, hinges and hardened die-struck pieces. | 470 | 550 | 6 | 160 HB | 86 % IACS |
Spring hard | Heavily cold-worked strip and wire for springy clasps, pin stems and contact springs. | 480 | 540 | 2 | 147 HB | 82 % IACS |
What is Coin Silver 900-O?
Coin Silver 900-O is Coin Silver 900 in the O temper — default stocked condition for sheet/wire that will be raised, stamped, bent or die-struck. Coin Silver 900-O has a yield strength of 100 MPa (14.5 ksi) and a tensile strength of 290 MPa (42.1 ksi) — weaker than 84% of precious metal grades. Elongation at break is 40% and the elastic modulus is 78 GPa (11.3 Msi). Coin Silver 900-O 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).
Advantages
- 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
- Polishes to a fine finish — 95/100, better than 86% of precious metal grades
- Conducts heat well — 330 W/m·K (190.7 BTU/hr·ft·°F), better than 84% of precious metal grades
Limitations
- Low stiffness — 78 GPa (11.3 Msi), worse than 90% of precious metal grades
- Low strength — 100 MPa (14.5 ksi), worse than 84% of precious metal grades
Coin Silver 900-O properties
Typical room-temperature values for Coin Silver 900-O; 13 are specific to this condition. Other listed values are Coin Silver 900 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
Coin Silver 900-O 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
Coin Silver 900-O has a yield strength of 100 MPa (14.5 ksi) and a tensile strength of 290 MPa (42.1 ksi) — weaker than 84% of precious metal grades. Elongation at break is 40% and the elastic modulus is 78 GPa (11.3 Msi).
Thermal6
Coin Silver 900-O is rated for continuous service to 250°C (482 °F). It conducts heat at 330 W/m·K (190.7 BTU/hr·ft·°F), better than 84% of precious metal grades. Thermal expansion is 18.9 µm/m·K (10.5 µin/in·°F).
Electrical3
Coin Silver 900-O conducts electricity at 85 % IACS, better than 88% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 70% of precious metal grades.
Sustainability3
Producing a kilogram of Coin Silver 900-O takes about 1,450 MJ of energy and emits 100 kg of CO₂ — less than 54% of precious metal grades. Typical recycled content is 40%.
Manufacturability8
Coin Silver 900-O's machinability is fair (40/100, worse than 60% of precious metal grades); weldability good (55/100); formability excellent (88/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Coin Silver 900-O
Is Coin Silver 900 easy to machine?
Very ductile and gummy in the soft temper — turn in half-hard or harder, use sharp polished-flute HSS/carbide, high speed, light feed, generous lubricant, and collect all chips for refining.
Can Coin Silver 900 be welded?
High thermal conductivity makes fusion welding tricky; laser or PUK pulse-arc welding with matching filler works well, and hard/medium/easy silver solders or Ag-Cu-Zn brazing alloys are the normal joining route.
Can Coin Silver 900 be formed, bent or molded?
Excellent cold formability when dead soft (deep draw, raise, roll, die strike); work hardens faster than 925 sterling so interstage anneal at 600–650 °C with rapid quench every 40–50% reduction.
What surface finishes work on Coin Silver 900?
Takes a mirror polish easily; remove copper firescale by pickling in warm citric/sulfuric acid or depletion-silvering, then protect with rhodium plating, anti-tarnish lacquer or sulfur-free storage.
Coin Silver 900 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 |
|---|---|---|
| Agfineness 900; assay tolerance per national coinage/hallmark law | 89.5 – 90.5 | 90 |
| Pbtrace impurity limit; causes hot shortness | ≤ 0.01 | — |
| Znincidental, from recycled feed | ≤ 0.05 | — |
| Feincidental impurity | ≤ 0.02 | — |
| Cubalance, nominally 10% | balance | — |
Coin Silver 900-O — frequently asked
What is Coin Silver 900-O used for?
Coin Silver 900-O is typically used for antique flatware, coin-silver jewelry and restoration replicas. In short: harder than 925 sterling; historic US coinage fineness; high-conductivity silver alloy.
What is the yield strength of Coin Silver 900-O?
Coin Silver 900-O has a typical yield strength of 100 MPa (14.5 ksi) and a tensile strength of 290 MPa (42.1 ksi) — weaker than 84% of precious metal grades. Strength varies by condition: see the 7 listed tempers.
Is Coin Silver 900-O easy to machine?
Not especially — machinability is rated fair (40/100, worse than 60% of precious metal grades). Very ductile and gummy in the soft temper — turn in half-hard or harder, use sharp polished-flute HSS/carbide, high speed, light feed, generous lubricant, and collect all chips for refining.
Can Coin Silver 900-O be welded?
Yes — weldability is rated good (55/100). High thermal conductivity makes fusion welding tricky; laser or PUK pulse-arc welding with matching filler works well, and hard/medium/easy silver solders or Ag-Cu-Zn brazing alloys are the normal joining route.
What surface finishes work on Coin Silver 900-O?
Takes a mirror polish easily; remove copper firescale by pickling in warm citric/sulfuric acid or depletion-silvering, then protect with rhodium plating, anti-tarnish lacquer or sulfur-free storage.
Can Coin Silver 900-O be formed, bent or molded?
Excellent cold formability when dead soft (deep draw, raise, roll, die strike); work hardens faster than 925 sterling so interstage anneal at 600–650 °C with rapid quench every 40–50% reduction.
What is the maximum service temperature of Coin Silver 900-O?
Coin Silver 900-O 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 Coin Silver 900-O and Coin Silver 900-H08?
O is the default condition — default stocked condition for sheet/wire that will be raised, stamped, bent or die-struck. H08: heavily cold-worked strip and wire for springy clasps, pin stems and contact springs. Yield strength is 100 MPa in O versus 480 MPa in H08.
Sources
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (precious metals) — ASM International (1990)
- ASM Handbook Vol. 3 — Alloy Phase Diagrams (Ag–Cu system) — ASM International (1992)
- Properties of silver and silver alloys — technical data — The Silver Institute (2020)
- Proceedings of the Santa Fe Symposium on Jewelry Manufacturing Technology (silver alloy mechanical data, firescale and annealing practice) — Met-Chem Research (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.