Silver 900
Mat Grades internal verification confirms source-backed fidelity and data integrity. It does not constitute external certification or guaranteed lot conformity. Read engineering disclaimer →
Key Engineering Properties
Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.
Engineering Summary
Silver 900 (often designated Coin Silver / UNS P07900) contains 90.0% silver and 10.0% copper. Historically the legal standard for United States coinage prior to 1965, its increased copper concentration creates a strong, wear-resistant alloy extensively employed in heavy-duty sliding electrical contacts, instrument commutators, and high-vibration electromechanical devices.
Silver 900 Documented Applications
- ›Heavy-duty electromechanical contact discs, rivets, and commutator segments
- ›Rotary switch wiper contacts and high-cycle slip rings
- ›Historic legal coinage, commemorative medallions, and tokens
- ›High-wear utilitarian cutlery and industrial instrumentation
Recognized Aliases
Source-backed commercial trade name and short designations cataloged in canonical data.
Silver 900 Specifications & Designations
Standard Designations & Applicable Specifications — Semantically classified designations distinguishing primary standard identifiers, commercial trade names, and applicable specification references.
| System | Identifier | Standard System Name | Classification Notes & Provenance |
|---|---|---|---|
| UNSPRIMARY | P07900 | Unified Numbering System | —Ref: Standard Specifications for Silver & Silver Alloys (ASTM B742, ASTM B413, ISO 9202, DIN 17510) |
| ISO | Ag900 | International Organization for Standardization | —Ref: Standard Specifications for Silver & Silver Alloys (ASTM B742, ASTM B413, ISO 9202, DIN 17510) |
| US-COIN | Coin Silver 900 | US Coinage Standard | —Ref: Standard Specifications for Silver & Silver Alloys (ASTM B742, ASTM B413, ISO 9202, DIN 17510) |
| DIN | Ag900 | Deutsches Institut für Normung | —Ref: Standard Specifications for Silver & Silver Alloys (ASTM B742, ASTM B413, ISO 9202, DIN 17510) |
| EN | AgCu10 | European Norm | —Ref: Standard Specifications for Silver & Silver Alloys (ASTM B742, ASTM B413, ISO 9202, DIN 17510) |
| Recognized Name / Alias | Classification | Technical Usage & Context |
|---|---|---|
| 900 Silver | Colloquial Alias | Colloquial or commercial industry synonym |
| Coin Silver | Commercial Alias | Colloquial or commercial industry synonym |
| UNS P07900 | Commercial Alias | Colloquial or commercial industry synonym |
| Ag900 | Commercial Alias | Colloquial or commercial industry synonym |
| Standards Body | Specification Code | Specification Title / Scope | Relationship Type |
|---|---|---|---|
| ISO | ISO 9202 | Jewellery and precious metals — Fineness of precious metal alloys | Specification Reference |
| DIN | DIN 17510 | Feinsilber und Silberlegierungen (Fine silver and silver alloys) | Specification Reference |
| ISO | ISO 9202 Fineness of Precious Metal Alloys | Applicable specification reference. | Specification Reference |
Silver 900 Chemical Composition
Chemical Composition (Weight %) — Elemental limits and values from the cited source. Preserves exact semantic limits (minimums, maximums, and ranges).
| Element | Symbol | Atomic No. | Semantic Basis | Specified Value | Unit | Metallurgical Notes & Qualification | Data Status |
|---|---|---|---|---|---|---|---|
| Silver | Ag | 47 | MINIMUM | ≥ 90.00 | wt% | Ref: ASTM International & ISO / DIN Standards Technical Committees | VERIFIED |
| Copper | Cu | 29 | RANGE | 9.80 – 10.00 | wt% | Ref: ASTM International & ISO / DIN Standards Technical Committees | VERIFIED |
Silver 900 Physical Properties
Source-specific physical properties. Test temperatures are shown only where reported.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Density | 10.31 g/cm³ | TYPICAL | Test Temp: 20 °C | 10.31 g/cm³ | ASTM International & Standards Technical Committees | VERIFIED |
Silver 900 Thermal & Thermodynamic Properties
Phase change temperatures, thermal conductivity, specific heat, mean coefficients of thermal expansion across standardized temperature ranges, and recommended thermal processing windows.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Thermal Conductivity | 395 W/(m·K) | TYPICAL | Test Temp: 20 °C | 395 W/(m·K) | ASTM International & Standards Technical Committees | VERIFIED |
| Melting Range (Solidus-Liquidus) | 779 – 875 °C | RANGE | Solidus 779°C (Ag-Cu eutectic point), Liquidus 875°C | 779 – 875 °C | ASTM International & Standards Technical Committees | VERIFIED |
Silver 900 Electrical Properties
Electrical conductivity and resistivity in their reported units and conditions.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Electrical Conductivity | 78 % IACS | TYPICAL | Test Temp: 20 °C | 78 % IACS | ASTM International & Standards Technical Committees | VERIFIED |
| Electrical Resistivity | 22.1 nΩ·m | TYPICAL | Test Temp: 20 °C | 22.1 nΩ·m | ASTM International & Standards Technical Committees | VERIFIED |
Silver 900 Mechanical Properties
Contextual Mechanical Properties & Tempers: Engineering strength, ductility, and hardness values grouped by product form, temper, and section thickness. Mechanical properties are contextual and not isotropic averages.
| Product Form | Temper / Condition | Section Size | Tensile (UTS) | Yield Strength | Elongation | Shear Strength | Fatigue Strength | Hardness (Scales Preserved) | Status |
|---|---|---|---|---|---|---|---|---|---|
| Strip & Wire | Annealed (Soft)Source values and qualifiersYield Strength (0.2% Offset): ≥ 150 MPa (TYPICAL)ASTM International & ISO / DIN Standards Technical Committees — ASTM B742, ASTM B413, ISO 9202, DIN 17510 Ultimate Tensile Strength: ≥ 240 MPa (TYPICAL)ASTM International & ISO / DIN Standards Technical Committees — ASTM B742, ASTM B413, ISO 9202, DIN 17510 Elongation at Break: ≥ 26 % (TYPICAL)ASTM International & ISO / DIN Standards Technical Committees — ASTM B742, ASTM B413, ISO 9202, DIN 17510 | — | ≥ 240 MPa | ≥ 150 MPa | ≥ 26 % | — | — | — | VERIFIED |
| Strip & Wire | Hard Rolled (50% reduction)Source values and qualifiersYield Strength (0.2% Offset): ≥ 410 MPa (TYPICAL)ASTM International & ISO / DIN Standards Technical Committees — ASTM B742, ASTM B413, ISO 9202, DIN 17510 Ultimate Tensile Strength: ≥ 470 MPa (TYPICAL)ASTM International & ISO / DIN Standards Technical Committees — ASTM B742, ASTM B413, ISO 9202, DIN 17510 Elongation at Break: ≥ 3 % (TYPICAL)ASTM International & ISO / DIN Standards Technical Committees — ASTM B742, ASTM B413, ISO 9202, DIN 17510 | — | ≥ 470 MPa | ≥ 410 MPa | ≥ 3 % | — | — | — | VERIFIED |
| Standard Product Form | Annealed (Soft)Source values and qualifiersHV Hardness: 72–88 HV (TYPICAL)ASTM International & ISO / DIN Standards Technical Committees — ASTM B742, ASTM B413, ISO 9202, DIN 17510 | — | — | — | — | — | — | 72–88 HV | VERIFIED |
| Standard Product Form | Hard Rolled (50% reduction)Source values and qualifiersHV Hardness: 150–178 HV (TYPICAL)ASTM International & ISO / DIN Standards Technical Committees — ASTM B742, ASTM B413, ISO 9202, DIN 17510 | — | — | — | — | — | — | 150–178 HV | VERIFIED |
Silver 900 Processing & Fabrication
Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.
Machinability
Rated at approximately 50% relative to C36000. Chips break more easily than in sterling silver; suitable for automatic screw machining.
Weldability & Joining
Readily brazed; requires active brazing fluxes to prevent surface cuprous oxide formation.
Heat Treatment & Working Ranges
Solution heat treated at 740°C followed by quench; precipitation hardenable at 280°C to 300°C to achieve 135-155 HV.
Forming & Cold Working
Readily cold coined and stamped; exhibits moderate strain hardening requiring controlled reduction schedules.
Silver 900 Equivalent & Comparable Grades
Comparable Grades & Cross-References: Carefully classified cross-reference relationships for Silver 900. Comparable does not mean equivalent.
| Related Material | Family | Relationship Classification | Metallurgical Notes & Differences | Status | Action |
|---|---|---|---|---|---|
| Sterling Silver 925 | Silver & Silver Alloys | Commonly Compared | Silver 900 contains more copper (10% vs 7.5%), providing higher annealed yield strength (160 MPa vs 135 MPa) and wear resistance at a modest decrease in conductivity (78% vs 84% IACS).Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost). | VERIFIED | Side-by-Side Compare → |
| Silver 800 | Silver & Silver Alloys | Commonly Compared | Silver 900 retains greater corrosion resistance and higher electrical conductivity (78% vs 68% IACS) than 800 silver.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost). | VERIFIED | Side-by-Side Compare → |
Sources
Sources & Provenance Trail: Authoritative reference publications, standards specifications, and data registers cited across this material record.
Authoritative data harmonized across ASTM B742, ASTM B413, ISO 9202, DIN 17510, British Hallmarking Act 1973, and ASM International monographs.