Copper Alloys•Phosphor Bronze•

VERIFIED(Source-Verified)

C51000 Phosphor Bronze 5% A

Primary Designation:UNS C51000

Aliases:

Phosphor Bronze 5% Grade A5% Phosphor BronzeC51000

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:6 composition elements and 96 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

8.858 g/cm³TYPICAL · at 20 °C

Electrical Conductivity

15 % IACSTYPICAL · at 20 °C

Thermal Conductivity

69.23 W/(m·K)TYPICAL · at 20 °C

Specific Heat Capacity

376.8 J/(kg·K)TYPICAL · at 20 °C

Melting Range (Solidus / Liquidus)

954.4 – 1048.9 °C1750.0 – 1920.0 °F

Solidus: 954.4°C | Liquidus: 1048.9°C

Composition Excerpt

Cu BALANCE wt%Copper (balance)

Standard Elemental Basis: BALANCE

Engineering Summary

UNS C51000 Phosphor Bronze (5% Sn, 0.03-0.35% P) is the industry standard alloy for high-reliability electrical spring contacts, diaphragms, switch components, and sleeve bushings. It features outstanding fatigue endurance, resistance to stress relaxation, high elastic modulus (110 GPa), and immunity to season cracking.

C51000 Phosphor Bronze 5% A Documented Applications

›Architecture: Bridge Bearing Plates
›Beater Bar: Friction & Wear Properties
›Beater Bar: Mechanical Properties
›Beater Bar: Thermal Properties
›Bellows: Drawing Characteristics
›Bellows: Non-Fouling
›Bourdon Tubes: Corrosion Resistance
›Bourdon Tubes: Mechanical Properties
›Bourdon Tubes: Thermal Properties
›Bridge Bearing Plates: Corrosion Resistance
›Bridge Bearing Plates: Forming Characteristics
›Bridge Bearing Plates: Mechanical Properties

Recognized Aliases

Source-backed commercial trade name and short designations cataloged in canonical data.

Phosphor Bronze 5% Grade A5% Phosphor BronzeC51000

C51000 Phosphor Bronze 5% A Specifications & Designations

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

Direct Standard DesignationsDIRECT DESIGNATION

2 Primary Identifiers

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System	Identifier	Standard System Name	Classification Notes & Provenance
UNSPRIMARY	C51000	Unified Numbering System	Unified Numbering System standard designation for copper alloys (CDA / SAE / ASTM)Ref: CDA UNS Standard Designations Register (C51000)
CDA	Alloy 510	Copper Development Association Alloy Number	CDA three-digit legacy designationRef: CDA UNS Standard Designations Register (C51000)

Recognized Commercial Aliases & Trade NamesCOMMON ALIAS

4 Listed

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Recognized Name / Alias	Classification	Technical Usage & Context
Phosphor Bronze Grade A	Standard Commercial Name	CDA Standard Commercial Name
Phosphor Bronze 5% Grade A	Commercial Alias	Colloquial or commercial industry synonym
5% Phosphor Bronze	Commercial Alias	Colloquial or commercial industry synonym
C51000	Commercial Alias	Colloquial or commercial industry synonym

Applicable Specifications & Product Form ReferencesSPECIFICATION REFERENCE

12 Applicable Standards

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Standards Body	Specification Code	Specification Title / Scope	Relationship Type
ASTM	ASTM B139/B139M	PHOSPHOR BRONZE ROD, BAR AND SHAPES	Specification Reference
AMS	AMS 4625	PHOSPHOR BRONZE BARS, RODS, AND TUBING, HARD TEMPER	Specification Reference
ASTM	ASTM B103/B103M	PHOSPHOR BRONZE PLATE, SHEET, STRIP AND ROLLED BAR	Specification Reference
MILITARY	MILITARY MIL-B-13501	BEARINGS AND BUSHINGS, BRASS AND BRONZE MACHINED OR FORMED	Specification Reference
ASTM	ASTM F468	NONFERROUS BOLTS, HEX CAP SCREWS, AND STUDS FOR GENERAL USE	Specification Reference
ASTM	ASTM F467	NONFERROUS NUTS FOR GENERAL USE	Specification Reference
ASTM	ASTM B100	ROLLED COPPER ALLOY BEARING AND EXPANSION PLATES AND SHEETS FOR BRIDGE AND OTHER STRUCTURAL USES	Specification Reference
AMS	AMS 4510	PHOSPHOR BRONZE SHEET, STRIP AND PLATE, SPRING TEMPER	Specification Reference
SAE	SAE J463	WROUGHT COPPER AND COPPER ALLOYS	Specification Reference
SAE	SAE J461	WROUGHT AND CAST COPPER ALLOYS	Specification Reference
ASTM	ASTM B888/B88M	COPPER ALLOY STRIP FOR USE IN MANUFACTURE OF ELECTRICAL CONNECTORS OR SPRING CONTACTS	Specification Reference
MILITARY	MILITARY MIL-T-3595	TUBING, PHOSPHOR BRONZE: ROUND, SEAMLESS	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.

C51000 Phosphor Bronze 5% A Chemical Composition

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

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Element	Symbol	Atomic No.	Semantic Basis	Specified Value	Unit	Metallurgical Notes & Qualification	Data Status
Copper	Cu	29	BALANCE	Balance	wt%	Remainder element (Copper).Ref: Copper Development Association (CDA)	VERIFIED
Lead	Pb	82	MAXIMUM	≤ 0.05	wt%	CDA chemical composition specification limits for C51000: max 0.05 wt%.Ref: Copper Development Association (CDA)	VERIFIED
Tin	Sn	50	RANGE	4.20 – 5.80	wt%	CDA chemical composition specification limits for C51000: 4.2 - 5.8 wt%.Ref: Copper Development Association (CDA)	VERIFIED
Zinc	Zn	30	MAXIMUM	≤ 0.30	wt%	CDA chemical composition specification limits for C51000: max 0.3 wt%.Ref: Copper Development Association (CDA)	VERIFIED
Iron	Fe	26	MAXIMUM	≤ 0.10	wt%	CDA chemical composition specification limits for C51000: max 0.1 wt%.Ref: Copper Development Association (CDA)	VERIFIED
Phosphorus	P	15	RANGE	0.03 – 0.35	wt%	CDA chemical composition specification limits for C51000: 0.03 - 0.35 wt%.Ref: Copper Development Association (CDA)	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:

C51000 Phosphor Bronze 5% A Physical Properties

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

1 Parameters

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Property Parameter	Canonical SI Value	Semantic Basis	Test Temperature / Context Range	Source Raw Reference	Source Reference	Status
Density	8.858 g/cm³	TYPICAL	Test Temp: 20 °CCDA Physical Properties: Density 0.32 lb/cu in. at 68°F (8.858 g/cm³ at 20°C)	0.32 lb/cu in. at 68°F	Copper Development Association Inc.	VERIFIED

C51000 Phosphor Bronze 5% A Thermal & Thermodynamic Properties

Phase change temperatures, thermal conductivity, specific heat, mean coefficients of thermal expansion across standardized temperature ranges, and recommended thermal processing windows.

6 Parameters

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Property Parameter	Canonical SI Value	Semantic Basis	Test Temperature / Context Range	Source Raw Reference	Source Reference	Status
Liquidus Temperature	1048.9 °C	TYPICAL	CDA Physical Properties: Liquidus temperature 1920.0 °F (1048.9 °C)	1920.0 °F	Copper Development Association Inc.	VERIFIED
Solidus Temperature	954.4 °C	TYPICAL	CDA Physical Properties: Solidus temperature 1750.0 °F (954.4 °C)	1750.0 °F	Copper Development Association Inc.	VERIFIED
Thermal Conductivity	69.23 W/(m·K)	TYPICAL	Test Temp: 20 °CCDA Physical Properties: Thermal conductivity 40.0 Btu/(ft·hr·°F) (69.23 W/(m·K) at 20°C)	40.0 Btu/ sq ft/ ft hr/ °F at 68°F	Copper Development Association Inc.	VERIFIED
Coefficient of Thermal Expansion (CTE)	17.82 µm/(m·K)	TYPICAL	CDA Physical Properties: CTE 9.9 µin/(in·°F) (17.82 µm/(m·K)) over range 68-57210°F	9.9 10^-6 per °F	Copper Development Association Inc.	VERIFIED
Specific Heat Capacity	376.8 J/(kg·K)	TYPICAL	Test Temp: 20 °CCDA Physical Properties: Specific heat 0.09 Btu/(lb·°F) (376.8 J/(kg·K))	0.09 Btu/ lb /°F at 68°F	Copper Development Association Inc.	VERIFIED
Annealing Temperature Range	482.2 – 676.7 °C	RANGE	CDA Thermal Treatments: Annealing temperature range 900 - 1250°F (482.2 - 676.7°C)	900 – 1250 °F	Copper Development Association Inc.	VERIFIED

C51000 Phosphor Bronze 5% A Electrical Properties

Electrical conductivity and resistivity in their reported units and conditions.

1 Parameters

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Property Parameter	Canonical SI Value	Semantic Basis	Test Temperature / Context Range	Source Raw Reference	Source Reference	Status
Electrical Conductivity	15 % IACS	TYPICAL	Test Temp: 20 °CCDA Physical Properties: Volume conductivity 15.0 % IACS at 68°F (20°C)	15.0 % IACS at 68°F	Copper Development Association Inc.	VERIFIED

C51000 Phosphor Bronze 5% A 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 (Tension)

110.3 GPa

CDA Physical Properties: Elastic modulus in tension 16000.0 ksi (110.3 GPa)

Modulus of Rigidity

41368.5 MPa

CDA Physical Properties: Shear modulus 6000.0 ksi (41368.5 MPa)

Machinability Rating

20 %

CDA Fabrication Properties: Rating relative to Free-Cutting Brass (C36000 = 100%).

Product Form:

Temper / Condition:

Showing 38 of 38 conditions

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Product Form	Temper / Condition	Section Size	Tensile (UTS)	Yield Strength	Elongation	Shear Strength	Fatigue Strength	Hardness (Scales Preserved)	Status
Flat Products	1/2 Hard (H02) · 20 °C Source values and qualifiers Tensile Strength: 455.1 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 372.3 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 24 % (TYPICAL)Copper Development Association (CDA) — H02	—	455.1 MPa	372.3 MPa	24 %	—	—	—	VERIFIED
Flat Products	1/2 Hard (H02) Source values and qualifiers Rockwell B Hardness: 78 HRB (TYPICAL)Copper Development Association (CDA) — Rockwell 30T Hardness: 69 HR30T (TYPICAL)Copper Development Association (CDA) — H02	—	—	—	—	—	—	78 HRB69 HR30T	VERIFIED
Flat Products	1/2 Hard and Stress Relieved (HR02) · 20 °C Source values and qualifiers Tensile Strength: 455.1 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 372.3 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 28 % (TYPICAL)Copper Development Association (CDA) — HR02	—	455.1 MPa	372.3 MPa	28 %	—	—	—	VERIFIED
Flat Products	1/4 Hard (H01) · 20 °C Source values and qualifiers Tensile Strength: 337.8 MPa (TYPICAL)Copper Development Association (CDA) — Elongation: 24 % (TYPICAL)Copper Development Association (CDA) — H01	—	337.8 MPa	—	24 %	—	—	—	VERIFIED
Flat Products	Annealed (O61) · 20 °C Source values and qualifiers Tensile Strength: 317.2 MPa (TYPICAL)Copper Development Association (CDA) — Elongation: 47 % (TYPICAL)Copper Development Association (CDA) — O61	—	317.2 MPa	—	47 %	—	—	—	VERIFIED
Flat Products	As Hot Rolled (M20) · 20 °C Source values and qualifiers Tensile Strength: 344.7 MPa (TYPICAL)Copper Development Association (CDA) — M20	—	344.7 MPa	—	—	—	—	—	VERIFIED
Flat Products	Extra Hard (H06) · 20 °C Source values and qualifiers Tensile Strength: 661.9 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 634.3 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 3 % (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — H06	0.04	661.9 MPa	634.3 MPa	3 %	—	—	—	VERIFIED
Flat Products	Extra Hard (H06) Source values and qualifiers Rockwell B Hardness: 93 HRB (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Rockwell 30T Hardness: 78 HR30T (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — H06	0.04	—	—	—	—	—	93 HRB78 HR30T	VERIFIED
Flat Products	Extra Spring (H10) · 20 °C Source values and qualifiers Tensile Strength: 737.7 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 710.2 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 2 % (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — H10	0.04	737.7 MPa	710.2 MPa	2 %	—	—	—	VERIFIED
Flat Products	Extra Spring (H10) Source values and qualifiers Rockwell B Hardness: 97 HRB (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Rockwell 30T Hardness: 80 HR30T (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — H10	0.04	—	—	—	—	—	97 HRB80 HR30T	VERIFIED
Flat Products	Hard (H04) · 20 °C Source values and qualifiers Tensile Strength: 579.2 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 551.6 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 7 % (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — H04	0.04	579.2 MPa	551.6 MPa	7 %	—	—	—	VERIFIED
Flat Products	Hard (H04) Source values and qualifiers Rockwell B Hardness: 87 HRB (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Rockwell 30T Hardness: 75 HR30T (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Fatigue Strength: 172.4 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; 10^8 cycles endurance limitCopper Development Association (CDA) — H04	0.04	—	—	—	—	172.4 MPa	87 HRB75 HR30T	VERIFIED
Flat Products	Hard and Stress Relieved (HR04) · 20 °C Source values and qualifiers Tensile Strength: 579.2 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 510.2 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 14 % (TYPICAL)Copper Development Association (CDA) — HR04	—	579.2 MPa	510.2 MPa	14 %	—	—	—	VERIFIED
Flat Products	Nominal Grain Size 0.015 mm (OS015) · 20 °C Source values and qualifiers Tensile Strength: 365.4 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 151.7 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 50 % (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — OS015	0.04	365.4 MPa	151.7 MPa	50 %	—	—	—	VERIFIED
Flat Products	Nominal Grain Size 0.015 mm (OS015) Source values and qualifiers Rockwell B Hardness: 34 HRB (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Rockwell F Hardness: 79 HRF (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — OS015	0.04	—	—	—	—	—	34 HRB79 HRF	VERIFIED
Flat Products	Nominal Grain Size 0.025 mm (OS025) · 20 °C Source values and qualifiers Tensile Strength: 344.7 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 144.8 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 52 % (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — OS025	0.04	344.7 MPa	144.8 MPa	52 %	—	—	—	VERIFIED
Flat Products	Nominal Grain Size 0.025 mm (OS025) Source values and qualifiers Rockwell B Hardness: 30 HRB (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Rockwell F Hardness: 77 HRF (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — OS025	0.04	—	—	—	—	—	30 HRB77 HRF	VERIFIED
Flat Products	Nominal Grain Size 0.035 mm (OS035) · 20 °C Source values and qualifiers Tensile Strength: 337.8 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 137.9 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 58 % (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — OS035	0.04	337.8 MPa	137.9 MPa	58 %	—	—	—	VERIFIED
Flat Products	Nominal Grain Size 0.035 mm (OS035) Source values and qualifiers Rockwell B Hardness: 28 HRB (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Rockwell F Hardness: 75 HRF (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — OS035	0.04	—	—	—	—	—	28 HRB75 HRF	VERIFIED
Flat Products	Nominal Grain Size 0.050 mm (OS050) · 20 °C Source values and qualifiers Tensile Strength: 324.1 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 131 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 64 % (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — OS050	0.04	324.1 MPa	131 MPa	64 %	—	—	—	VERIFIED
Flat Products	Nominal Grain Size 0.050 mm (OS050) Source values and qualifiers Rockwell B Hardness: 26 HRB (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Rockwell F Hardness: 73 HRF (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — OS050	0.04	—	—	—	—	—	26 HRB73 HRF	VERIFIED
Flat Products	Soft Anneal (O60) · 20 °C Source values and qualifiers Tensile Strength: 344.7 MPa (TYPICAL)Copper Development Association (CDA) — O60	—	344.7 MPa	—	—	—	—	—	VERIFIED
Flat Products	Soft Anneal (O60) Source values and qualifiers Rockwell B Hardness: 40 HRB (TYPICAL)Copper Development Association (CDA) — O60	—	—	—	—	—	—	40 HRB	VERIFIED
Flat Products	Spring (H08) · 20 °C Source values and qualifiers Tensile Strength: 710.2 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 682.6 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 3 % (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — H08	0.04	710.2 MPa	682.6 MPa	3 %	—	—	—	VERIFIED
Flat Products	Spring (H08) Source values and qualifiers Rockwell B Hardness: 95 HRB (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Rockwell 30T Hardness: 79 HR30T (TYPICAL)Section Size: 0.04; Section Size: 0.04 inCopper Development Association (CDA) — Fatigue Strength: 151.7 MPa (TYPICAL)Section Size: 0.04; Section Size: 0.04 in; 10^8 cycles endurance limitCopper Development Association (CDA) — H08	0.04	—	—	—	—	151.7 MPa	95 HRB79 HR30T	VERIFIED
Flat Products	Spring and Stress Relieved (HR08) · 20 °C Source values and qualifiers Tensile Strength: 710.2 MPa (TYPICAL)Copper Development Association (CDA) — Elongation: 9 % (TYPICAL)Copper Development Association (CDA) — HR08	—	710.2 MPa	—	9 %	—	—	—	VERIFIED
Rod	1/2 Hard (H02) · 20 °C Source values and qualifiers Tensile Strength: 482.6 MPa (TYPICAL)Section Size: 1; Cold Work: 20%; Section Size: 1 inCopper Development Association (CDA) — Elongation: 25 % (TYPICAL)Section Size: 1; Cold Work: 20%; Section Size: 1 inCopper Development Association (CDA) — H02	1	482.6 MPa	—	25 %	—	—	—	VERIFIED
Rod	1/2 Hard (H02) Source values and qualifiers Rockwell B Hardness: 78 HRB (TYPICAL)Section Size: 1; Cold Work: 20%; Section Size: 1 inCopper Development Association (CDA) — H02	1	—	—	—	—	—	78 HRB	VERIFIED
Rod	1/2 Hard (H02) · 20 °C Source values and qualifiers Tensile Strength: 517.1 MPa (TYPICAL)Section Size: 0.5; Cold Work: 20%; Section Size: 0.5 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 448.2 MPa (TYPICAL)Section Size: 0.5; Cold Work: 20%; Section Size: 0.5 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 25 % (TYPICAL)Section Size: 0.5; Cold Work: 20%; Section Size: 0.5 inCopper Development Association (CDA) — H02	0.5	517.1 MPa	448.2 MPa	25 %	—	—	—	VERIFIED
Rod	1/2 Hard (H02) Source values and qualifiers Rockwell B Hardness: 80 HRB (TYPICAL)Section Size: 0.5; Cold Work: 20%; Section Size: 0.5 inCopper Development Association (CDA) — H02	0.5	—	—	—	—	—	80 HRB	VERIFIED
Wire	1/2 Hard (H02) · 20 °C Source values and qualifiers Tensile Strength: 586.1 MPa (TYPICAL)Section Size: 0.08; Section Size: 0.08 inCopper Development Association (CDA) — Elongation: 8 % (TYPICAL)Section Size: 0.08; Section Size: 0.08 inCopper Development Association (CDA) — H02	0.08	586.1 MPa	—	8 %	—	—	—	VERIFIED
Wire	1/4 Hard (H01) · 20 °C Source values and qualifiers Tensile Strength: 468.8 MPa (TYPICAL)Section Size: 0.08; Section Size: 0.08 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 413.7 MPa (TYPICAL)Section Size: 0.08; Section Size: 0.08 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 24 % (TYPICAL)Section Size: 0.08; Section Size: 0.08 inCopper Development Association (CDA) — H01	0.08	468.8 MPa	413.7 MPa	24 %	—	—	—	VERIFIED
Wire	Extra Hard (H06) · 20 °C Source values and qualifiers Tensile Strength: 896.3 MPa (TYPICAL)Section Size: 0.08; Cold Work: 75%; Section Size: 0.08 inCopper Development Association (CDA) — Elongation: 3 % (TYPICAL)Section Size: 0.08; Cold Work: 75%; Section Size: 0.08 inCopper Development Association (CDA) — H06	0.08	896.3 MPa	—	3 %	—	—	—	VERIFIED
Wire	Extra Hard (H06) Source values and qualifiers Fatigue Strength: 206.8 MPa (TYPICAL)Section Size: 0.08; Cold Work: 75%; Section Size: 0.08 in; 10^8 cycles endurance limitCopper Development Association (CDA) — H06	0.08	—	—	—	—	206.8 MPa	—	VERIFIED
Wire	Hard (H04) · 20 °C Source values and qualifiers Tensile Strength: 758.4 MPa (TYPICAL)Section Size: 0.08; Section Size: 0.08 inCopper Development Association (CDA) — Elongation: 3 % (TYPICAL)Section Size: 0.08; Section Size: 0.08 inCopper Development Association (CDA) — H04	0.08	758.4 MPa	—	3 %	—	—	—	VERIFIED
Wire	Hard (H04) Source values and qualifiers Fatigue Strength: 186.2 MPa (TYPICAL)Section Size: 0.08; Section Size: 0.08 in; 10^8 cycles endurance limitCopper Development Association (CDA) — H04	0.08	—	—	—	—	186.2 MPa	—	VERIFIED
Wire	Nominal Grain Size 0.035 mm (OS035) · 20 °C Source values and qualifiers Tensile Strength: 344.7 MPa (TYPICAL)Section Size: 0.08; Section Size: 0.08 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 137.9 MPa (TYPICAL)Section Size: 0.08; Section Size: 0.08 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 58 % (TYPICAL)Section Size: 0.08; Section Size: 0.08 inCopper Development Association (CDA) — OS035	0.08	344.7 MPa	137.9 MPa	58 %	—	—	—	VERIFIED
Wire	Spring (H08) · 20 °C Source values and qualifiers Tensile Strength: 965.3 MPa (TYPICAL)Section Size: 0.08; Cold Work: 84%; Section Size: 0.08 inCopper Development Association (CDA) — Elongation: 2 % (TYPICAL)Section Size: 0.08; Cold Work: 84%; Section Size: 0.08 inCopper Development Association (CDA) — H08	0.08	965.3 MPa	—	2 %	—	—	—	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

C51000 Phosphor Bronze 5% A Processing & Fabrication

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

Source: Copper Development Association (CDA)

Machinability

Machinability rating: 20% relative to free-cutting brass (C36000 = 100%).

Weldability & Joining

Soldering: Excellent; Brazing: Excellent; Oxyacetylene Welding: Fair; Gas Shielded Arc Welding: Good; Coated Metal Arc Welding: Fair; Spot Weld: Good; Seam Weld: Fair; Butt Weld: Excellent

Heat Treatment & Working Ranges

Annealing temperature range: 482.2°C to 676.7°C (900°F - 1250°F).

Forming & Cold Working

Capacity for Being Cold Worked: Excellent. Capacity for Being Hot Formed: Poor.

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 C51000 Phosphor Bronze 5% A states: Machinability rating: 20% relative to free-cutting brass (C36000 = 100%). A relevant hardness example is Rockwell B Hardness: 78 HRB (typical; 1/2 Hard (H02), H02, Flat Products). 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: Soldering: Excellent; Brazing: Excellent; Oxyacetylene Welding: Fair; Gas Shielded Arc Welding: Good; Coated Metal Arc Welding: Fair; Spot Weld: Good; Seam Weld: Fair; Butt Weld: Excellent The first cataloged strength example is Tensile Strength: 455.1 MPa (typical; 1/2 Hard (H02), H02, Flat Products; test temperature 20 °C). 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

Review the working fluid, cleaning agents and dissimilar-metal contacts as separate exposures. The word copper, brass or bronze is too broad to establish compatibility. A process rating does not qualify a pressure boundary, and a thermal-property measurement does not establish a continuous service-temperature limit. The recorded thermal example is Thermal Conductivity: 69.23 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 Pb maximum 0.05 wt%, Sn 4.2–5.8 wt%. Chemistry documents identity; it does not establish fluid compatibility.

Selection trade-offs & applications

Use UNS C51000, COMMERCIAL Phosphor Bronze Grade A, CDA Alloy 510 to identify the candidate, then specify the product form and delivered condition separately. The catalog lists Architecture: Bridge Bearing Plates as an application example. The related candidate C52100 Phosphor Bronze 8% C 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: Copper Development Association (CDA); Copper Development Association (CDA)

C51000 Phosphor Bronze 5% A Equivalent & Comparable Grades

Comparable Grades & Cross-References: Carefully classified cross-reference relationships for C51000 Phosphor Bronze 5% A. Comparable does not mean equivalent.

Scroll horizontally for relationship classifications & comparisons

Related Material	Family	Relationship Classification	Metallurgical Notes & Differences	Status
C52100 Phosphor Bronze 8% C	Copper Alloys	Commonly Compared	C51000 (5% Sn, Grade A) is the standard phosphor bronze for electrical contacts and spring relays (15% IACS). C52100 (8% Sn, Grade C) provides higher tensile and yield strength with superior wear resistance at slightly lower conductivity (13% IACS).Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).	VERIFIED
C54400 Free-Machining Phosphor Bronze (B-2)	Copper Alloys	Commonly Compared	C51000 provides maximum fatigue endurance for stamped spring contacts (20% machinability); C54400 adds 3.5-4.5% Pb for 80% machinability in turned bushings.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).	VERIFIED
C65500 High-Silicon Bronze A	Copper Alloys	Commonly Compared	C51000 is chosen for cyclic electrical spring endurance; C65500 is chosen for high-strength weldable marine fasteners and pressure vessels.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).	VERIFIED

Phosphor Bronze Alloy Family

Copper alloys sharing common alloying formulations and metallurgical classifications under the Phosphor Bronze branch.

3 Adjacent Grades

C51000Current Grade

C51000 Phosphor Bronze 5% A

C52100

C52100 Phosphor Bronze 8% C

View Grade →

C54400

C54400 Free-Machining Phosphor Bronze (B-2)

View Grade →

Sources

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

Copper Development Association Inc.CDA Alloy C51000 Property & Specification Profile

AUTHORITATIVE BODY

Copper Development Association authoritative technical reference profile for C51000 Phosphor Bronze 5% A.

Issuing Body: Copper Development Association (CDA)View Source Record ↗

Copper Development Association Inc.CDA UNS Standard Designations Register (C51000)

AUTHORITATIVE BODY

Unified Numbering System (UNS) designation registration register confirming active C51000 status.

Issuing Body: Copper Development Association (CDA)View 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.