VERIFIED(Source-Verified)

Silver 900

Primary Designation:UNS P07900

Aliases:

900 SilverCoin SilverUNS P07900Ag900

Mat Grades internal verification confirms source-backed fidelity and data integrity. It does not constitute external certification or guaranteed lot conformity. Read engineering disclaimer →

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Data Completeness:2 composition elements and 14 condition-specific property values cataloged.

Omitted fields represent unverified properties. "Missing is better than invented."

Key Engineering Properties

Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.

Density

10.31 g/cm³TYPICAL · at 20 °C

Electrical Conductivity

78 % IACSTYPICAL · at 20 °C

Thermal Conductivity

395 W/(m·K)TYPICAL · at 20 °C

Melting Point

undefined °C

Composition Excerpt

Ag ≥ 90 wt%Silver (min)

Standard Elemental Basis: MIN

Tensile Strength

≥ 240 MPaTYPICAL · Annealed (Soft) · temperature not stated

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.

900 SilverCoin SilverUNS P07900Ag900

Silver 900 Specifications & Designations

Standard Designations & Applicable Specifications — Semantically classified designations distinguishing primary standard identifiers, commercial trade names, and applicable specification references.

Direct Standard DesignationsDIRECT DESIGNATION

5 Primary Identifiers

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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 Commercial Aliases & Trade NamesCOMMON ALIAS

4 Listed

Scroll horizontally for full alias classifications

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

Applicable Specifications & Product Form ReferencesSPECIFICATION REFERENCE

3 Applicable Standards

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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

Engineering Notice: Applicable specifications establish manufacturing requirements, dimensional tolerances, and test criteria for specific product forms (e.g. bus bar, wire, plate, pipe). They represent applicable technical standards, not alternative or equivalent alloy grades.

Silver 900 Chemical Composition

Chemical Composition (Weight %) — Elemental limits and values from the cited source. Preserves exact semantic limits (minimums, maximums, and ranges).

Scroll horizontally for full elemental limits

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

* Elemental percentages are expressed in weight percent (wt%). Values represent applicable specification limits. Unspecified trace elements are not fabricated or assumed.Preserves exact semantic basis

Property Display UnitsSwitch between Canonical SI and Source / US Customary units:

Silver 900 Physical Properties

Source-specific physical properties. Test temperatures are shown only where reported.

1 Parameters

Scroll horizontally for full property parameters

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.

2 Parameters

Scroll horizontally for full property parameters

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.

2 Parameters

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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.

Elastic & Baseline Mechanical ConstantsSource-specific measurement conditions

Modulus of Elasticity

83 GPa

Product Form:

Temper / Condition:

Showing 4 of 4 conditions

Scroll horizontally for all conditions & tempers

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 qualifiers Yield 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 qualifiers Yield 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 qualifiers HV 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 qualifiers HV Hardness: 150–178 HV (TYPICAL)ASTM International & ISO / DIN Standards Technical Committees — ASTM B742, ASTM B413, ISO 9202, DIN 17510	—	—	—	—	—	—	150–178 HV	VERIFIED

Hardness Integrity Notice: Rockwell B (HRB), Rockwell F (HRF), and Superficial 30T (HR30T) scales are reported on their measured scales without cross-scale mathematical conversion.

Source: See fact-level citations

Silver 900 Processing & Fabrication

Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.

Source: ASTM International & ISO / DIN Standards Technical Committees

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.

Practical Engineering & Fabrication Notes

By Mat Grades Editorial Desk · Updated 2026-11-14. Use alongside the specified product standard and supplier certificate.

Machining & shop-floor behavior

The cataloged machining note for Silver 900 states: Rated at approximately 50% relative to C36000. Chips break more easily than in sterling silver; suitable for automatic screw machining. A relevant hardness example is HV Hardness: 72–88 HV (typical; Annealed (Soft)). Use that supplied condition for a trial of the difficult feature. Record tool changes, burr removal, unclamped dimensions and accepted parts per hour. Relative machinability ratings from different reference scales should not be compared as if they were one common test.

Weldability, brazing & joining

The available joining assessment states: Readily brazed; requires active brazing fluxes to prevent surface cuprous oxide formation. The first cataloged strength example is Yield Strength (0.2% Offset): minimum 150 MPa (typical; Annealed (Soft), Strip & Wire). Assess the final part after joining or thermal processing. Include distortion, cleanup and inspection in the quotation. A material designation or favorable process rating is a starting point for qualification, not evidence that an untested joint meets the drawing.

Corrosion & service environment

Distinguish appearance, electrical contact behavior and mechanical wear in the service requirement. Tarnish resistance is not the same as freedom from surface films in every atmosphere. Check the mating material, cleaning method and final condition rather than using nominal purity as the only acceptance criterion. The recorded thermal example is Thermal Conductivity: 395 W/(m·K) (typical; ; test temperature 20 °C). State the exposure and inspection access in the design record so that a change of installation or cleaning method triggers a review. The selected composition entries are Ag minimum 90 wt%, Cu 9.8–10 wt%. Chemistry documents identity; it does not establish fluid compatibility.

Selection trade-offs & applications

Use UNS P07900, ISO Ag900, US-COIN Coin Silver 900 to identify the candidate, then specify the product form and delivered condition separately. The catalog lists Heavy-duty electromechanical contact discs, rivets, and commutator segments as an application example. The related candidate Sterling Silver 925 is linked for comparison; its commonly compared relationship must be checked before substitution. Compare the complete route through machining, joining, finish and inspection. Keep the certificate, required test location and acceptance criteria with the first-article record. A later change of grade, condition or source should be assessed against that same requirement.

Technical references: ASTM International & ISO / DIN Standards Technical Committees

Silver 900 Equivalent & Comparable Grades

Comparable Grades & Cross-References: Carefully classified cross-reference relationships for Silver 900. Comparable does not mean equivalent.

Scroll horizontally for relationship classifications & comparisons

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
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

Related Engineering & Metallurgy Guides

Contextual technical guides explaining degradation mechanisms, testing methodologies, and selection criteria relevant to Silver 900.

Material Selection12 min read

Density of Silver: Pure, Sterling, Temperature Effects & Calculator

Silver possesses the highest electrical and thermal conductivity of any metallic element, accompanied by a solid room-temperature density of 10.49 g/cm³ (10,490 kg/m³). Because common alloying additions—chiefly copper—possess lower densities, precision volumetric measurement provides a fundamental non-destructive methodology for alloy purity and fineness verification.

Author: Mat Grades Editorial DeskRead Guide →

Sources

Sources & Provenance Trail: Authoritative reference publications, standards specifications, and data registers cited across this material record.

ASTM International & Standards Technical CommitteesStandard Specifications for Silver & Silver Alloys (ASTM B742, ASTM B413, ISO 9202, DIN 17510)

STANDARDS ORG

Authoritative data harmonized across ASTM B742, ASTM B413, ISO 9202, DIN 17510, British Hallmarking Act 1973, and ASM International monographs.

Issuing Body: ASTM International & ISO / DIN Standards Technical CommitteesRevision: ASTM B742-20 / ISO 9202:2019 / DIN 17510View Source Record ↗

Intellectual Property & Provenance Notice: Mat Grades cites technical literature from recognized industry associations and standards organizations. Underlying technical standards and publication data remain the intellectual property of their respective issuing organizations.