Copper Alloys•Beryllium Copper•

VERIFIED(Source-Verified)

C17200 Beryllium Copper (Alloy 25)

Primary Designation:UNS C17200

Aliases:

Alloy 25Beryllium Copper 25C17200

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:5 composition elements and 145 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

8.027 g/cm³TYPICAL · at 20 °C

Electrical Conductivity

22 % IACSTYPICAL · at 20 °C

Thermal Conductivity

107.31 W/(m·K)TYPICAL · at 20 °C

Specific Heat Capacity

418.7 J/(kg·K)TYPICAL · at 20 °C

Melting Range (Solidus / Liquidus)

865.6 – 982.2 °C1590.0 – 1800.0 °F

Solidus: 865.6°C | Liquidus: 982.2°C

Composition Excerpt

Cu BALANCE wt%Copper (balance)

Standard Elemental Basis: BALANCE

Engineering Summary

UNS C17200 Beryllium Copper (Alloy 25) is the highest-strength commercial copper alloy, containing 1.80% to 2.00% beryllium and minimum 0.20% cobalt plus nickel. Following precipitation age-hardening (heat treatment), it achieves tensile strengths exceeding 1380 MPa (200 ksi) and hardness up to 45 HRC while retaining non-magnetic behavior and non-sparking safety.

C17200 Beryllium Copper (Alloy 25) Documented Applications

›Bearings: Friction & Wear Properties
›Bearings: Machining Characteristics
›Bearings: Mechanical Properties
›Belleville Washers: Forming Characteristics
›Belleville Washers: Mechanical Properties
›Bellows: Corrosion Resistance
›Bellows: Forming Characteristics
›Bellows: Mechanical Properties
›Bolts: Creep Properties
›Bolts: Mechanical Properties
›Bolts: Softening Resistance
›Bourdon Tubes: Corrosion Resistance

Recognized Aliases

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

Alloy 25Beryllium Copper 25C17200

C17200 Beryllium Copper (Alloy 25) 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	C17200	Unified Numbering System	Unified Numbering System standard designation for copper alloys (CDA / SAE / ASTM)Ref: CDA UNS Standard Designations Register (C17200)
CDA	Alloy 172	Copper Development Association Alloy Number	CDA three-digit legacy designationRef: CDA UNS Standard Designations Register (C17200)

Recognized Commercial Aliases & Trade NamesCOMMON ALIAS

4 Listed

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Recognized Name / Alias	Classification	Technical Usage & Context
Beryllium Copper Alloy 25	Standard Commercial Name	CDA Standard Commercial Name
Alloy 25	Commercial Alias	Colloquial or commercial industry synonym
Beryllium Copper 25	Commercial Alias	Colloquial or commercial industry synonym
C17200	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
AMS	AMS 4533	COPPER BERYLLINUM ALLOY BARS AND RODS, SOLUTION AND PRECIPITATION HEAT TREATED	Specification Reference
AMS	AMS 4534	COPPER BERYLLIUM ALLOY BARS AND RODS, SOLUTION HEAT TREATED, COLD WORKED AND PRECIPITATION HEAT TREA	Specification Reference
AMS	AMS 4651	COPER-BERYLLIUM ALLOY BARS AND RODS, HARD TEMPER	Specification Reference
AMS	AMS 4650	COPPER-BERYLLIUM ALLOY BARS, RODS AND FORGINGS, SOLUTION HEAT TREATED	Specification Reference
ASTM	ASTM B196/B196M	COPPER BERYLLIUM ALLOY ROD AND BAR	Specification Reference
SAE	SAE J463	WROUGHT COPPER AND COPPER ALLOYS	Specification Reference
ASTM	ASTM B194	COPPER BERYLLIUM ALLOY PLATE, SHEET, STRIP, AND ROLLED BAR	Specification Reference
MILITARY	MILITARY MIL-C-21657	COPPER-BERYLLIUM ALLOY, LOW MAGNETIC EFFECT (FOR SPECIAL PURPOSE TOOLS AND EQUIPMENT)	Specification Reference
SAE	SAE J461	WROUGHT AND CAST COPPER ALLOYS	Specification Reference
ASTM	ASTM B570	COPPER-BERYLLIUM ALLOY FORGINGS AND EXTRUSIONS	Specification Reference
AMS	AMS 4530	COPPER-BERYLLIUM ALLOY SHEET, STRIP, AND PLATE - SOLUTION TREATED	Specification Reference
AMS	AMS 4532	COPPER BERYLLIUM ALOY SHEET AND STRIP, HALF-HARD	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.

C17200 Beryllium Copper (Alloy 25) 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
Aluminum	Al	13	MAXIMUM	≤ 0.20	wt%	CDA chemical composition specification limits for C17200: max 0.2 wt%.Ref: Copper Development Association (CDA)	VERIFIED
Beryllium	Be	4	RANGE	1.80 – 2.00	wt%	CDA chemical composition specification limits for C17200: 1.8 - 2.0 wt%.Ref: Copper Development Association (CDA)	VERIFIED
Cobalt	Co	27	MINIMUM	≥ 0.20	wt%	CDA chemical composition specification limits for C17200: min 0.2 wt%.Ref: Copper Development Association (CDA)	VERIFIED
Silicon	Si	14	MAXIMUM	≤ 0.20	wt%	CDA chemical composition specification limits for C17200: max 0.2 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:

C17200 Beryllium Copper (Alloy 25) 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	8.027 g/cm³	TYPICAL	Test Temp: 20 °CCDA Physical Properties: Density 0.29 lb/cu in. at 68°F (8.027 g/cm³ at 20°C)	0.29 lb/cu in. at 68°F	Copper Development Association Inc.	VERIFIED

C17200 Beryllium Copper (Alloy 25) Thermal & Thermodynamic Properties

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

5 Parameters

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Property Parameter	Canonical SI Value	Semantic Basis	Test Temperature / Context Range	Source Raw Reference	Source Reference	Status
Liquidus Temperature	982.2 °C	TYPICAL	CDA Physical Properties: Liquidus temperature 1800.0 °F (982.2 °C)	1800.0 °F	Copper Development Association Inc.	VERIFIED
Solidus Temperature	865.6 °C	TYPICAL	CDA Physical Properties: Solidus temperature 1590.0 °F (865.6 °C)	1590.0 °F	Copper Development Association Inc.	VERIFIED
Thermal Conductivity	107.31 W/(m·K)	TYPICAL	Test Temp: 20 °CCDA Physical Properties: Thermal conductivity 62.0 Btu/(ft·hr·°F) (107.31 W/(m·K) at 20°C)	62.0 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	418.7 J/(kg·K)	TYPICAL	Test Temp: 20 °CCDA Physical Properties: Specific heat 0.1 Btu/(lb·°F) (418.7 J/(kg·K))	0.1 Btu/ lb /°F at 68°F	Copper Development Association Inc.	VERIFIED

C17200 Beryllium Copper (Alloy 25) 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	22 % IACS	TYPICAL	Test Temp: 20 °CCDA Physical Properties: Volume conductivity 22.0 % IACS at 68°F (20°C)	22.0 % IACS at 68°F	Copper Development Association Inc.	VERIFIED

C17200 Beryllium Copper (Alloy 25) 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)

127.6 GPa

CDA Physical Properties: Elastic modulus in tension 18500.0 ksi (127.6 GPa)

Modulus of Rigidity

50331.7 MPa

CDA Physical Properties: Shear modulus 7300.0 ksi (50331.7 MPa)

Machinability Rating

20 %

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

Forgeability Rating

40 —

CDA Fabrication Properties: Relative forgeability rating.

Product Form:

Temper / Condition:

Showing 55 of 55 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 and Precipitation Heat Treated (TH02) · 20 °C Source values and qualifiers Tensile Strength: 1344.5 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 1206.6 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 3 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TH02	0.188	1344.5 MPa	1206.6 MPa	3 %	—	—	—	VERIFIED
Flat Products	1/2 Hard and Precipitation Heat Treated (TH02) Source values and qualifiers Rockwell C Hardness: 41 HRC (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Fatigue Strength: 303.4 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; 10^8 cycles endurance limitCopper Development Association (CDA) — TH02	0.188	—	—	—	—	303.4 MPa	41 HRC	VERIFIED
Flat Products	1/4 Hard and Precipitation Heat Treated (TH01) · 20 °C Source values and qualifiers Tensile Strength: 1275.5 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 1137.6 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 4 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TH01	0.188	1275.5 MPa	1137.6 MPa	4 %	—	—	—	VERIFIED
Flat Products	1/4 Hard and Precipitation Heat Treated (TH01) Source values and qualifiers Rockwell C Hardness: 40 HRC (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Fatigue Strength: 275.8 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; 10^8 cycles endurance limitCopper Development Association (CDA) — TH01	0.188	—	—	—	—	275.8 MPa	40 HRC	VERIFIED
Flat Products	Hard and Precipitation Heat Treated (TH04) · 20 °C Source values and qualifiers Tensile Strength: 1379 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 1241.1 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 2 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TH04	0.188	1379 MPa	1241.1 MPa	2 %	—	—	—	VERIFIED
Flat Products	Hard and Precipitation Heat Treated (TH04) Source values and qualifiers Rockwell C Hardness: 42 HRC (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Fatigue Strength: 310.3 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; 10^8 cycles endurance limitCopper Development Association (CDA) — TH04	0.188	—	—	—	—	310.3 MPa	42 HRC	VERIFIED
Flat Products	Mill-hardened Temper, TM - 1/2 Hard (TM02) · 20 °C Source values and qualifiers Tensile Strength: 882.5 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 723.9 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 15 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM02	0.188	882.5 MPa	723.9 MPa	15 %	—	—	—	VERIFIED
Flat Products	Mill-hardened Temper, TM - 1/2 Hard (TM02) Source values and qualifiers Rockwell C Hardness: 27 HRC (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM02	0.188	—	—	—	—	—	27 HRC	VERIFIED
Flat Products	Mill-hardened Temper, TM - 1/2 Hard (TM00) · 20 °C Source values and qualifiers Tensile Strength: 723.9 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 565.4 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 20 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM00	0.188	723.9 MPa	565.4 MPa	20 %	—	—	—	VERIFIED
Flat Products	Mill-hardened Temper, TM - 1/2 Hard (TM00) Source values and qualifiers Rockwell C Hardness: 27 HRC (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM00	0.188	—	—	—	—	—	27 HRC	VERIFIED
Flat Products	Mill-hardened Temper, TM - 1/2 Hard (TM01) · 20 °C Source values and qualifiers Tensile Strength: 792.9 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 634.3 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 17 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM01	0.188	792.9 MPa	634.3 MPa	17 %	—	—	—	VERIFIED
Flat Products	Mill-hardened Temper, TM - 1/2 Hard (TM01) Source values and qualifiers Rockwell C Hardness: 23 HRC (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM01	0.188	—	—	—	—	—	23 HRC	VERIFIED
Flat Products	Mill-hardened Temper, TM - Hard (TM04) · 20 °C Source values and qualifiers Tensile Strength: 979.1 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 841.2 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 12 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM04	0.188	979.1 MPa	841.2 MPa	12 %	—	—	—	VERIFIED
Flat Products	Mill-hardened Temper, TM - Hard (TM04) Source values and qualifiers Rockwell C Hardness: 32 HRC (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM04	0.188	—	—	—	—	—	32 HRC	VERIFIED
Flat Products	Mill-hardened Temper, TM - SHM (TM05) · 20 °C Source values and qualifiers Tensile Strength: 1034.2 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 861.8 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 9 % (TYPICAL)Copper Development Association (CDA) — TM05	—	1034.2 MPa	861.8 MPa	9 %	—	—	—	VERIFIED
Flat Products	Mill-hardened Temper, TM - SHM (TM05) Source values and qualifiers Rockwell C Hardness: 31 HRC (TYPICAL)Copper Development Association (CDA) — TM05	—	—	—	—	—	—	31 HRC	VERIFIED
Flat Products	Mill-hardened Temper, TM - XHMS Spring (TM08) · 20 °C Source values and qualifiers Tensile Strength: 1254.8 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 1103.2 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 6 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM08	0.188	1254.8 MPa	1103.2 MPa	6 %	—	—	—	VERIFIED
Flat Products	Mill-hardened Temper, TM -XHM - Extra Hard (TM06) · 20 °C Source values and qualifiers Tensile Strength: 1158.3 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 1020.4 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 7 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM06	0.188	1158.3 MPa	1020.4 MPa	7 %	—	—	—	VERIFIED
Flat Products	Mill-hardened Temper, TM -XHM - Extra Hard (TM06) Source values and qualifiers Rockwell C Hardness: 37 HRC (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TM06	0.188	—	—	—	—	—	37 HRC	VERIFIED
Flat Products	Precipitation Hardened (TF00) · 20 °C Source values and qualifiers Tensile Strength: 1206.6 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 1068.7 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 6 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TF00	0.188	1206.6 MPa	1068.7 MPa	6 %	—	—	—	VERIFIED
Flat Products	Precipitation Hardened (TF00) Source values and qualifiers Rockwell C Hardness: 38 HRC (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Fatigue Strength: 248.2 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; 10^8 cycles endurance limitCopper Development Association (CDA) — TF00	0.188	—	—	—	—	248.2 MPa	38 HRC	VERIFIED
Flat Products	Solution Heat Treated (TB00) · 20 °C Source values and qualifiers Tensile Strength: 482.6 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 220.6 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 45 % (TYPICAL)Copper Development Association (CDA) — TB00	—	482.6 MPa	220.6 MPa	45 %	—	—	—	VERIFIED
Flat Products	Solution Heat Treated (TB00) Source values and qualifiers Rockwell B Hardness: 60 HRB (TYPICAL)Copper Development Association (CDA) — Rockwell 30T Hardness: 58 HR30T (TYPICAL)Copper Development Association (CDA) — TB00	—	—	—	—	—	—	60 HRB58 HR30T	VERIFIED
Flat Products	Solution Heat Treated and Cold Worked: 1/2 Hard (TD02) · 20 °C Source values and qualifiers Tensile Strength: 634.3 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 565.4 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 15 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TD02	0.188	634.3 MPa	565.4 MPa	15 %	—	—	—	VERIFIED
Flat Products	Solution Heat Treated and Cold Worked: 1/2 Hard (TD02) Source values and qualifiers Rockwell B Hardness: 92 HRB (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Rockwell 30T Hardness: 77 HR30T (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TD02	0.188	—	—	—	—	—	92 HRB77 HR30T	VERIFIED
Flat Products	Solution Heat Treated and Cold Worked: 1/4 Hard (TD01) · 20 °C Source values and qualifiers Tensile Strength: 551.6 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 482.6 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 25 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TD01	0.188	551.6 MPa	482.6 MPa	25 %	—	—	—	VERIFIED
Flat Products	Solution Heat Treated and Cold Worked: 1/4 Hard (TD01) Source values and qualifiers Rockwell B Hardness: 80 HRB (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Rockwell 30T Hardness: 70 HR30T (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TD01	0.188	—	—	—	—	—	80 HRB70 HR30T	VERIFIED
Flat Products	Solution Heat Treated and Cold Worked: Hard (TD04) · 20 °C Source values and qualifiers Tensile Strength: 758.4 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 717.1 MPa (TYPICAL)Section Size: 0.188; Section Size: 0.188 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 5 % (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TD04	0.188	758.4 MPa	717.1 MPa	5 %	—	—	—	VERIFIED
Flat Products	Solution Heat Treated and Cold Worked: Hard (TD04) Source values and qualifiers Rockwell B Hardness: 99 HRB (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — Rockwell 30T Hardness: 81 HR30T (TYPICAL)Section Size: 0.188; Section Size: 0.188 inCopper Development Association (CDA) — TD04	0.188	—	—	—	—	—	99 HRB81 HR30T	VERIFIED
Rod	Hard and Precipitation Heat Treated (TH04) · 20 °C Source values and qualifiers Tensile Strength: 1413.4 MPa (TYPICAL)Section Size: 0.375; Section Size: 0.375 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 1103.2 MPa (TYPICAL)Section Size: 0.375; Section Size: 0.375 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 2 % (TYPICAL)Section Size: 0.375; Section Size: 0.375 inCopper Development Association (CDA) — Tensile Strength: 1379 MPa (TYPICAL)Section Size: 0.375; Section Size: 0.375 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 1068.7 MPa (TYPICAL)Section Size: 0.375; Section Size: 0.375 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 2 % (TYPICAL)Section Size: 0.375; Section Size: 0.375 inCopper Development Association (CDA) — TH04	0.375	1379 MPa	1068.7 MPa	2 %	—	—	—	VERIFIED
Rod	Hard and Precipitation Heat Treated (TH04) Source values and qualifiers Rockwell C Hardness: 42 HRC (TYPICAL)Section Size: 0.375; Section Size: 0.375 inCopper Development Association (CDA) — Rockwell C Hardness: 41 HRC (TYPICAL)Section Size: 0.375; Section Size: 0.375 inCopper Development Association (CDA) — TH04	0.375	—	—	—	—	—	42 HRC41 HRC	VERIFIED
Rod	Hard and Precipitation Heat Treated (TH04) · 20 °C Source values and qualifiers Tensile Strength: 1344.5 MPa (TYPICAL)Section Size: 3; Section Size: 3 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 999.7 MPa (TYPICAL)Section Size: 3; Section Size: 3 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 4 % (TYPICAL)Section Size: 3; Section Size: 3 inCopper Development Association (CDA) — TH04	3	1344.5 MPa	999.7 MPa	4 %	—	—	—	VERIFIED
Rod	Hard and Precipitation Heat Treated (TH04) Source values and qualifiers Rockwell C Hardness: 41 HRC (TYPICAL)Section Size: 3; Section Size: 3 inCopper Development Association (CDA) — TH04	3	—	—	—	—	—	41 HRC	VERIFIED
Rod	Precipitation Hardened (TF00) · 20 °C Source values and qualifiers Tensile Strength: 1254.8 MPa (TYPICAL)Section Size: 3; Section Size: 3 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 896.3 MPa (TYPICAL)Section Size: 3; Section Size: 3 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 3 % (TYPICAL)Section Size: 3; Section Size: 3 inCopper Development Association (CDA) — TF00	3	1254.8 MPa	896.3 MPa	3 %	—	—	—	VERIFIED
Rod	Precipitation Hardened (TF00) Source values and qualifiers Rockwell C Hardness: 39 HRC (TYPICAL)Section Size: 3; Section Size: 3 inCopper Development Association (CDA) — Fatigue Strength: 379.2 MPa (TYPICAL)Section Size: 3; Section Size: 3 in; 10^8 cycles endurance limitCopper Development Association (CDA) — TF00	3	—	—	—	—	379.2 MPa	39 HRC	VERIFIED
Rod	Precipitation Hardened (TF00) · 20 °C Source values and qualifiers Tensile Strength: 1254.8 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 999.7 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 4 % (TYPICAL)Copper Development Association (CDA) — TF00	—	1254.8 MPa	999.7 MPa	4 %	—	—	—	VERIFIED
Rod	Precipitation Hardened (TF00) Source values and qualifiers Rockwell C Hardness: 39 HRC (TYPICAL)Copper Development Association (CDA) — TF00	—	—	—	—	—	—	39 HRC	VERIFIED
Rod	Solution Heat Treated (TB00) · 20 °C Source values and qualifiers Tensile Strength: 496.4 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 137.9 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 20 % (TYPICAL)Copper Development Association (CDA) — TB00	—	496.4 MPa	137.9 MPa	20 %	—	—	—	VERIFIED
Rod	Solution Heat Treated (TB00) Source values and qualifiers Rockwell B Hardness: 65 HRB (TYPICAL)Copper Development Association (CDA) — TB00	—	—	—	—	—	—	65 HRB	VERIFIED
Rod	Solution Heat Treated and Cold Worked: Hard (TD04) · 20 °C Source values and qualifiers Tensile Strength: 758.4 MPa (TYPICAL)Section Size: 0.375; Section Size: 0.375 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 517.1 MPa (TYPICAL)Section Size: 0.375; Section Size: 0.375 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 8 % (TYPICAL)Section Size: 0.375; Section Size: 0.375 inCopper Development Association (CDA) — TD04	0.375	758.4 MPa	517.1 MPa	8 %	—	—	—	VERIFIED
Rod	Solution Heat Treated and Cold Worked: Hard (TD04) Source values and qualifiers Rockwell B Hardness: 95 HRB (TYPICAL)Section Size: 0.375; Section Size: 0.375 inCopper Development Association (CDA) — TD04	0.375	—	—	—	—	—	95 HRB	VERIFIED
Rod	Solution Heat Treated and Cold Worked: Hard (TD04) · 20 °C Source values and qualifiers Tensile Strength: 710.2 MPa (TYPICAL)Section Size: 3; Section Size: 3 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 517.1 MPa (TYPICAL)Section Size: 3; Section Size: 3 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 8 % (TYPICAL)Section Size: 3; Section Size: 3 inCopper Development Association (CDA) — TD04	3	710.2 MPa	517.1 MPa	8 %	—	—	—	VERIFIED
Rod	Solution Heat Treated and Cold Worked: Hard (TD04) Source values and qualifiers Rockwell B Hardness: 94 HRB (TYPICAL)Section Size: 3; Section Size: 3 inCopper Development Association (CDA) — TD04	3	—	—	—	—	—	94 HRB	VERIFIED
Rod	Solution Heat Treated and Cold Worked: Hard (TD04) · 20 °C Source values and qualifiers Tensile Strength: 744.6 MPa (TYPICAL)Section Size: 1; Section Size: 1 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 517.1 MPa (TYPICAL)Section Size: 1; Section Size: 1 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 8 % (TYPICAL)Section Size: 1; Section Size: 1 inCopper Development Association (CDA) — TD04	1	744.6 MPa	517.1 MPa	8 %	—	—	—	VERIFIED
Rod	Solution Heat Treated and Cold Worked: Hard (TD04) Source values and qualifiers Rockwell B Hardness: 95 HRB (TYPICAL)Section Size: 1; Section Size: 1 inCopper Development Association (CDA) — TD04	1	—	—	—	—	—	95 HRB	VERIFIED
Wire	1/2 Hard and Precipitation Heat Treated (TH02) · 20 °C Source values and qualifiers Tensile Strength: 1379 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 1275.5 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 1 % (TYPICAL)Copper Development Association (CDA) — TH02	—	1379 MPa	1275.5 MPa	1 %	—	—	—	VERIFIED
Wire	1/4 Hard and Precipitation Heat Treated (TH01) · 20 °C Source values and qualifiers Tensile Strength: 1310 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 1206.6 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 2 % (TYPICAL)Copper Development Association (CDA) — TH01	—	1310 MPa	1206.6 MPa	2 %	—	—	—	VERIFIED
Wire	3/4 Hard and Precipitation Heat Treated (TH03) · 20 °C Source values and qualifiers Tensile Strength: 1447.9 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 1344.5 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 1 % (TYPICAL)Copper Development Association (CDA) — TH03	—	1447.9 MPa	1344.5 MPa	1 %	—	—	—	VERIFIED
Wire	Hard and Precipitation Heat Treated (TH04) · 20 °C Source values and qualifiers Tensile Strength: 1461.7 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 1344.5 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 1 % (TYPICAL)Copper Development Association (CDA) — TH04	—	1461.7 MPa	1344.5 MPa	1 %	—	—	—	VERIFIED
Wire	Precipitation Hardened (TF00) · 20 °C Source values and qualifiers Tensile Strength: 1227.3 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 1103.2 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 3 % (TYPICAL)Copper Development Association (CDA) — TF00	—	1227.3 MPa	1103.2 MPa	3 %	—	—	—	VERIFIED
Wire	Solution Heat Treated (TB00) · 20 °C Source values and qualifiers Tensile Strength: 468.8 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 193.1 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 35 % (TYPICAL)Copper Development Association (CDA) — TB00	—	468.8 MPa	193.1 MPa	35 %	—	—	—	VERIFIED
Wire	Solution Heat Treated and Cold Worked: 1/2 Hard (TD02) · 20 °C Source values and qualifiers Tensile Strength: 841.2 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 689.5 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 5 % (TYPICAL)Copper Development Association (CDA) — TD02	—	841.2 MPa	689.5 MPa	5 %	—	—	—	VERIFIED
Wire	Solution Heat Treated and Cold Worked: 1/4 Hard (TD01) · 20 °C Source values and qualifiers Tensile Strength: 703.3 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 565.4 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 10 % (TYPICAL)Copper Development Association (CDA) — TD01	—	703.3 MPa	565.4 MPa	10 %	—	—	—	VERIFIED
Wire	Solution Heat Treated and Cold Worked: 3/4 Hard (TD03) · 20 °C Source values and qualifiers Tensile Strength: 979.1 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 827.4 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 2 % (TYPICAL)Copper Development Association (CDA) — TD03	—	979.1 MPa	827.4 MPa	2 %	—	—	—	VERIFIED
Wire	Solution Heat Treated and Cold Worked: Hard (TD04) · 20 °C Source values and qualifiers Tensile Strength: 1048 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 861.8 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 1 % (TYPICAL)Copper Development Association (CDA) — TD04	—	1048 MPa	861.8 MPa	1 %	—	—	—	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

C17200 Beryllium Copper (Alloy 25) 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%). Forgeability rating: 40.

Weldability & Joining

Soldering: Good; Brazing: Good; Oxyacetylene Welding: Not Recommended; Gas Shielded Arc Welding: Good; Coated Metal Arc Welding: Good; Spot Weld: Good; Seam Weld: Fair; Butt Weld: Fair

Forming & Cold Working

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

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 C17200 Beryllium Copper (Alloy 25) states: Machinability rating: 20% relative to free-cutting brass (C36000 = 100%). Forgeability rating: 40. A relevant hardness example is Rockwell C Hardness: 41 HRC (typical; 1/2 Hard and Precipitation Heat Treated (TH02), TH02, Flat Products, 0.188). 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: Good; Brazing: Good; Oxyacetylene Welding: Not Recommended; Gas Shielded Arc Welding: Good; Coated Metal Arc Welding: Good; Spot Weld: Good; Seam Weld: Fair; Butt Weld: Fair The first cataloged strength example is Tensile Strength: 1344.5 MPa (typical; 1/2 Hard and Precipitation Heat Treated (TH02), TH02, Flat Products, 0.188; 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: 107.31 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 Al maximum 0.2 wt%, Be 1.8–2 wt%. Chemistry documents identity; it does not establish fluid compatibility.

Selection trade-offs & applications

Use UNS C17200, COMMERCIAL Beryllium Copper Alloy 25, CDA Alloy 172 to identify the candidate, then specify the product form and delivered condition separately. The catalog lists Bearings: Friction & Wear Properties as an application example. The related candidate C17510 Beryllium Copper (Alloy 3) 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)

C17200 Beryllium Copper (Alloy 25) Equivalent & Comparable Grades

Comparable Grades & Cross-References: Carefully classified cross-reference relationships for C17200 Beryllium Copper (Alloy 25). Comparable does not mean equivalent.

Scroll horizontally for relationship classifications & comparisons

Related Material	Family	Relationship Classification	Metallurgical Notes & Differences	Status	Action
C17510 Beryllium Copper (Alloy 3)	Copper Alloys	Commonly Compared	C17200 (Alloy 25) is high-strength beryllium copper (1.8-2.0% Be) achieving tensile strengths up to 1400 MPa with 22% IACS conductivity. C17510 (Alloy 3) is high-conductivity BeCu (0.2-0.6% Be, 1.4-2.2% Ni) offering 45-60% IACS conductivity with moderate yield strength (up to 650 MPa).Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).	VERIFIED
C17500 Beryllium Copper (Alloy 10)	Copper Alloys	Commonly Compared	C17200 prioritizes maximum yield strength and hardness (up to 45 HRC), whereas C17500 prioritizes electrical conductivity (45% IACS) with moderate strength.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).	VERIFIED

Beryllium Copper Alloy Family

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

3 Adjacent Grades

C17200Current Grade

C17200 Beryllium Copper (Alloy 25)

C17500

C17500 Beryllium Copper (Alloy 10)

View Grade →

C17510

C17510 Beryllium Copper (Alloy 3)

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 C17200 Property & Specification Profile

AUTHORITATIVE BODY

Copper Development Association authoritative technical reference profile for C17200 Beryllium Copper (Alloy 25).

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

Copper Development Association Inc.CDA UNS Standard Designations Register (C17200)

AUTHORITATIVE BODY

Unified Numbering System (UNS) designation registration register confirming active C17200 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.