C17500 Beryllium Copper (Alloy 10)
Primary Designation:UNS C17500
Aliases:
Alloy 10Beryllium Copper 10C17500
Mat Grades internal verification confirms source-backed fidelity and data integrity. It does not constitute external certification, ASTM/CDA endorsement, or guaranteed material conformity for procurement.
Data Completeness & Record Integrity:6 composition elements and 68 contextual property values cataloged.
Omitted fields represent unverified parameters. "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
8.608 g/cm³TYPICAL · at 20 °C
Electrical Conductivity
45 % IACSTYPICAL · at 20 °C
Thermal Conductivity
207.69 W/(m·K)TYPICAL · at 20 °C
Specific Heat Capacity
418.7 J/(kg·K)TYPICAL · at 20 °C
Melting Range (Solidus / Liquidus)
1029.4 – 1068.3 °C1885.0 – 1955.0 °F
Solidus: 1029.4°C | Liquidus: 1068.3°CComposition Excerpt
Cu BALANCE wt%Copper (balance)
Standard Elemental Basis: BALANCEEngineering Summary
UNS C17500 Beryllium Copper (Alloy 10) is a precipitation-hardenable copper-cobalt-beryllium alloy (0.4-0.7% Be, 2.4-2.7% Co) offering high electrical conductivity (45% to 48% IACS) and thermal conductivity combined with moderate-to-high tensile strength (up to 760 MPa) for resistance welding electrodes, plunger tips, and high-current electrical switches.
Documented Product Applications (Cited CDA Reference Profile)
- ›Conductors: Corrosion Resistance
- ›Conductors: Creep Properties
- ›Conductors: Mechanical Properties
- ›Conductors: Softening Resistance
- ›Conductors: Solderability
- ›Connectors: Conductivity (Electrical)
- ›Connectors: Conductivity (Thermal)
- ›Connectors: Corrosion Resistance
- ›Connectors: Mechanical Properties
- ›Connectors: Softening Resistance
- ›Die casting plunger tips: Corrosion Resistance
- ›Die casting plunger tips: Creep Properties
Recognized Aliases
Source-backed commercial trade name and short designations cataloged in canonical data.
Alloy 10Beryllium Copper 10C17500
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| System | Identifier | Standard System Name | Classification Notes & Provenance |
|---|---|---|---|
| UNSPRIMARY | C17500 | Unified Numbering System | Unified Numbering System standard designation for copper alloys (CDA / SAE / ASTM)Ref: CDA UNS Standard Designations Register (C17500) |
| CDA | Alloy 175 | Copper Development Association Alloy Number | CDA three-digit legacy designationRef: CDA UNS Standard Designations Register (C17500) |
Recognized Commercial Aliases & Trade NamesCOMMON ALIAS
4 Listed| Recognized Name / Alias | Classification | Technical Usage & Context |
|---|---|---|
| Beryllium Copper Alloy 10 | Standard Commercial Name | CDA Standard Commercial Name |
| Alloy 10 | Commercial Alias | Colloquial or commercial industry synonym |
| Beryllium Copper 10 | Commercial Alias | Colloquial or commercial industry synonym |
| C17500 | Commercial Alias | Colloquial or commercial industry synonym |
Applicable Specifications & Product Form ReferencesSPECIFICATION REFERENCE
8 Applicable Standards| Standards Body | Specification Code | Specification Title / Scope | Relationship Type |
|---|---|---|---|
| ASTM | ASTM B441 | COPPER-COBALT-BERYLLIUM (UNS NO. C17500) AND COPPER-NICKEL-BERYLLIUM (UNS NO. C17510) ROD AND BAR | Specification Reference |
| ASTM | ASTM B534 | COPPER-COBALT-BERYLLIUM ALLOY, PLATE, SHEET, STRIP, AND ROLLED BAR | Specification Reference |
| ASTM | ASTM B870 | COPPER-BERYLLIUM ALLOY FORGINGS AND EXTRUSION ALLOYS (UNS Nos. C17500 AND C17510) | Specification Reference |
| SAE | SAE J463 | WROUGHT COPPER AND COPPER ALLOYS | Specification Reference |
| SAE | SAE J461 | WROUGHT AND CAST COPPER ALLOYS | Specification Reference |
| ASTM | ASTM B937 | COPPER-BERYLLIUM SEAMLESS TUBE (UNS Nos.17500 and 17510) | Specification Reference |
| MILITARY | MILITARY MIL-C-81021 | COPPER BERYLLIUM ALLOY (COPPER ALLOY NUMBERS C17500 AND C17510) STRIP | Specification Reference |
| ASTM | ASTM B888/B88M | COPPER ALLOY STRIP FOR USE IN MANUFACTURE OF ELECTRICAL CONNECTORS OR SPRING CONTACTS | 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.
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 |
|---|---|---|---|---|---|---|---|
| Copper | Cu | 29 | BALANCE | Balance | wt% | Remainder element (Copper).Ref: Copper Development Association (CDA) | VERIFIED |
| Iron | Fe | 26 | MAXIMUM | ≤ 0.10 | wt% | CDA chemical composition specification limits for C17500: max 0.1 wt%.Ref: Copper Development Association (CDA) | VERIFIED |
| Aluminum | Al | 13 | MAXIMUM | ≤ 0.20 | wt% | CDA chemical composition specification limits for C17500: max 0.2 wt%.Ref: Copper Development Association (CDA) | VERIFIED |
| Beryllium | Be | 4 | RANGE | 0.40 – 0.70 | wt% | CDA chemical composition specification limits for C17500: 0.4 - 0.7 wt%.Ref: Copper Development Association (CDA) | VERIFIED |
| Cobalt | Co | 27 | RANGE | 2.40 – 2.70 | wt% | CDA chemical composition specification limits for C17500: 2.4 - 2.7 wt%.Ref: Copper Development Association (CDA) | VERIFIED |
| Silicon | Si | 14 | MAXIMUM | ≤ 0.20 | wt% | CDA chemical composition specification limits for C17500: 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:
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 | 8.608 g/cm³ | TYPICAL | Test Temp: 20 °CCDA Physical Properties: Density 0.311 lb/cu in. at 68°F (8.608 g/cm³ at 20°C) | 0.311 lb/cu in. at 68°F | Copper Development Association Inc. | VERIFIED |
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 |
|---|---|---|---|---|---|---|
| Liquidus Temperature | 1068.3 °C | TYPICAL | CDA Physical Properties: Liquidus temperature 1955.0 °F (1068.3 °C) | 1955.0 °F | Copper Development Association Inc. | VERIFIED |
| Solidus Temperature | 1029.4 °C | TYPICAL | CDA Physical Properties: Solidus temperature 1885.0 °F (1029.4 °C) | 1885.0 °F | Copper Development Association Inc. | VERIFIED |
| Thermal Conductivity | 207.69 W/(m·K) | TYPICAL | Test Temp: 20 °CCDA Physical Properties: Thermal conductivity 120.0 Btu/(ft·hr·°F) (207.69 W/(m·K) at 20°C) | 120.0 Btu/ sq ft/ ft hr/ °F at 68°F | Copper Development Association Inc. | VERIFIED |
| Coefficient of Thermal Expansion (CTE) | 17.64 µm/(m·K) | TYPICAL | CDA Physical Properties: CTE 9.8 µin/(in·°F) (17.64 µm/(m·K)) over range 68-39210°F | 9.8 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 |
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 | 45 % IACS | TYPICAL | Test Temp: 20 °CCDA Physical Properties: Volume conductivity 45.0 % IACS at 68°F (20°C) | 45.0 % IACS at 68°F | Copper Development Association Inc. | VERIFIED |
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)
131 GPa
CDA Physical Properties: Elastic modulus in tension 19000.0 ksi (131.0 GPa)Modulus of Rigidity
51710.7 MPa
CDA Physical Properties: Shear modulus 7500.0 ksi (51710.7 MPa)Machinability Rating
40 %
CDA Fabrication Properties: Rating relative to Free-Cutting Brass (C36000 = 100%).Showing 30 of 30 conditions
| Product Form | Temper / Condition | Section Size | Tensile (UTS) | Yield Strength | Elongation | Shear Strength | Fatigue Strength | Hardness (Scales Preserved) | Status |
|---|---|---|---|---|---|---|---|---|---|
| Flat Products | Hard and Precipitation Heat Treated (TH04) · 20 °CSource values and qualifiersTensile Strength: 758.4 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 655 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 8 % (TYPICAL)Copper Development Association (CDA) — | — | 758.4 MPa | 655 MPa | 8 % | — | — | — | VERIFIED |
| Flat Products | Hard and Precipitation Heat Treated (TH04)Source values and qualifiersRockwell B Hardness: 98 HRB (TYPICAL)Copper Development Association (CDA) — Rockwell 30T Hardness: 81 HR30T (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 98 HRB81 HR30T | VERIFIED |
| Flat Products | Precipitation Hardened (TF00) · 20 °CSource values and qualifiersTensile Strength: 689.5 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 551.6 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 10 % (TYPICAL)Copper Development Association (CDA) — | — | 689.5 MPa | 551.6 MPa | 10 % | — | — | — | VERIFIED |
| Flat Products | Precipitation Hardened (TF00)Source values and qualifiersRockwell B Hardness: 96 HRB (TYPICAL)Copper Development Association (CDA) — Rockwell 30T Hardness: 80 HR30T (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 96 HRB80 HR30T | VERIFIED |
| Flat Products | Solution Heat Treated (TB00) · 20 °CSource values and qualifiersTensile Strength: 241.3 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 172.4 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 20 % (TYPICAL)Copper Development Association (CDA) — | — | 241.3 MPa | 172.4 MPa | 20 % | — | — | — | VERIFIED |
| Flat Products | Solution Heat Treated (TB00)Source values and qualifiersRockwell B Hardness: 32 HRB (TYPICAL)Copper Development Association (CDA) — Rockwell 30T Hardness: 36 HR30T (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 32 HRB36 HR30T | VERIFIED |
| Flat Products | Solution Heat Treated and Cold Worked: 1/2 Hard (TD02) · 20 °CSource values and qualifiersTensile Strength: 468.8 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 413.7 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 8 % (TYPICAL)Copper Development Association (CDA) — | — | 468.8 MPa | 413.7 MPa | 8 % | — | — | — | VERIFIED |
| Flat Products | Solution Heat Treated and Cold Worked: 1/2 Hard (TD02)Source values and qualifiersRockwell B Hardness: 70 HRB (TYPICAL)Copper Development Association (CDA) — Rockwell 30T Hardness: 64 HR30T (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 70 HRB64 HR30T | VERIFIED |
| Flat Products | Solution Heat Treated and Cold Worked: Hard (TD04) · 20 °CSource values and qualifiersTensile Strength: 482.6 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 379.2 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 3 % (TYPICAL)Copper Development Association (CDA) — | — | 482.6 MPa | 379.2 MPa | 3 % | — | — | — | VERIFIED |
| Flat Products | Solution Heat Treated and Cold Worked: Hard (TD04)Source values and qualifiersRockwell B Hardness: 83 HRB (TYPICAL)Copper Development Association (CDA) — Rockwell 30T Hardness: 72 HR30T (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 83 HRB72 HR30T | VERIFIED |
| Forgings | Precipitation Hardened (TF00) · 20 °CSource values and qualifiersTensile Strength: 792.9 MPa (TYPICAL)Section Size: 4; Section Size: 4 inCopper Development Association (CDA) — Yield Strength (0.5% Ext): 620.5 MPa (TYPICAL)Section Size: 4; Section Size: 4 in; Yield strength at 0.5% extension under loadCopper Development Association (CDA) — | 4 | 792.9 MPa | 620.5 MPa | — | — | — | — | VERIFIED |
| Forgings | Precipitation Hardened (TF00)Source values and qualifiersRockwell B Hardness: 92 HRB (TYPICAL)Section Size: 4; Section Size: 4 inCopper Development Association (CDA) — | 4 | — | — | — | — | — | 92 HRB | VERIFIED |
| Forgings | Solution Heat Treated (TB00) · 20 °CSource values and qualifiersTensile Strength: 289.6 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) — | — | 289.6 MPa | 137.9 MPa | — | — | — | — | VERIFIED |
| Forgings | Solution Heat Treated (TB00)Source values and qualifiersRockwell B Hardness: 50 HRB (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 50 HRB | VERIFIED |
| Rod | Hard and Precipitation Heat Treated (TH04) · 20 °CSource values and qualifiersTensile Strength: 792.9 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 758.4 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 14 % (TYPICAL)Copper Development Association (CDA) — | — | 792.9 MPa | 758.4 MPa | 14 % | — | — | — | VERIFIED |
| Rod | Hard and Precipitation Heat Treated (TH04)Source values and qualifiersRockwell B Hardness: 98 HRB (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 98 HRB | VERIFIED |
| Rod | Precipitation Hardened (TF00) · 20 °CSource values and qualifiersTensile Strength: 758.4 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 620.5 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 18 % (TYPICAL)Copper Development Association (CDA) — | — | 758.4 MPa | 620.5 MPa | 18 % | — | — | — | VERIFIED |
| Rod | Precipitation Hardened (TF00)Source values and qualifiersRockwell B Hardness: 96 HRB (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 96 HRB | VERIFIED |
| Rod | Solution Heat Treated (TB00) · 20 °CSource values and qualifiersTensile Strength: 310.3 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 172.4 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 28 % (TYPICAL)Copper Development Association (CDA) — | — | 310.3 MPa | 172.4 MPa | 28 % | — | — | — | VERIFIED |
| Rod | Solution Heat Treated (TB00)Source values and qualifiersRockwell B Hardness: 35 HRB (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 35 HRB | VERIFIED |
| Rod | Solution Heat Treated and Cold Worked: Hard (TD04) · 20 °CSource values and qualifiersTensile Strength: 496.4 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 448.2 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 12 % (TYPICAL)Copper Development Association (CDA) — | — | 496.4 MPa | 448.2 MPa | 12 % | — | — | — | VERIFIED |
| Rod | Solution Heat Treated and Cold Worked: Hard (TD04)Source values and qualifiersRockwell B Hardness: 68 HRB (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 68 HRB | VERIFIED |
| Tube | Hard and Precipitation Heat Treated (TH04) · 20 °CSource values and qualifiersTensile Strength: 758.4 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 551.6 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — | — | 758.4 MPa | 551.6 MPa | — | — | — | — | VERIFIED |
| Tube | Hard and Precipitation Heat Treated (TH04)Source values and qualifiersRockwell B Hardness: 95 HRB (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 95 HRB | VERIFIED |
| Tube | Precipitation Hardened (TF00) · 20 °CSource values and qualifiersTensile Strength: 689.5 MPa (TYPICAL)Copper Development Association (CDA) — Yield Strength (0.5% Ext): 551.6 MPa (TYPICAL)Yield strength at 0.5% extension under loadCopper Development Association (CDA) — Elongation: 45 % (TYPICAL)Copper Development Association (CDA) — | — | 689.5 MPa | 551.6 MPa | 45 % | — | — | — | VERIFIED |
| Tube | Precipitation Hardened (TF00)Source values and qualifiersRockwell B Hardness: 92 HRB (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 92 HRB | VERIFIED |
| Tube | Solution Heat Treated (TB00) · 20 °CSource values and qualifiersTensile Strength: 241.3 MPa (TYPICAL)Copper Development Association (CDA) — | — | 241.3 MPa | — | — | — | — | — | VERIFIED |
| Tube | Solution Heat Treated (TB00)Source values and qualifiersRockwell B Hardness: 50 HRB (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 50 HRB | VERIFIED |
| Tube | Solution Heat Treated and Cold Worked: Hard (TD04) · 20 °CSource values and qualifiersTensile Strength: 448.2 MPa (TYPICAL)Copper Development Association (CDA) — | — | 448.2 MPa | — | — | — | — | — | VERIFIED |
| Tube | Solution Heat Treated and Cold Worked: Hard (TD04)Source values and qualifiersRockwell B Hardness: 60 HRB (TYPICAL)Copper Development Association (CDA) — | — | — | — | — | — | — | 60 HRB | 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
Processing & Fabrication Characteristics
Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.
Machinability
Machinability rating: 40% relative to free-cutting brass (C36000 = 100%).
Weldability & Joining
Soldering: Good; Brazing: Good; Oxyacetylene Welding: Not Recommended; Gas Shielded Arc Welding: Fair; Coated Metal Arc Welding: Fair; Spot Weld: Good; Seam Weld: Fair; Butt Weld: Fair
Forming & Cold Working
Capacity for Being Cold Worked: Excellent. Capacity for Being Hot Formed: Good.
Comparable Grades & Cross-References
Carefully classified cross-reference relationships for C17500 Beryllium Copper (Alloy 10). Comparable does not mean equivalent.
| Related Material | Family | Relationship Classification | Metallurgical Notes & Differences | Status | Action |
|---|---|---|---|---|---|
| C17510 Beryllium Copper (Alloy 3) | Copper Alloys | Close Equivalent | C17500 (Alloy 10 Cu-Co-Be) and C17510 (Alloy 3 Cu-Ni-Be) are high-conductivity beryllium coppers sharing equivalent mechanical strength (up to 760 MPa) and 45-60% IACS conductivity envelopes.Direct commercial substitution is generally permissible subject to certified Mill Test Report (MTR) confirmation for critical applications. | VERIFIED | Side-by-Side Compare → |
| C17200 Beryllium Copper (Alloy 25) | Copper Alloys | Commonly Compared | C17500 provides 45% IACS electrical conductivity with moderate strength (up to 760 MPa), whereas C17200 provides extreme strength (up to 1400 MPa) at 22% IACS conductivity.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost). | VERIFIED | Side-by-Side Compare → |
Sources & Provenance Trail
Reference publications and standards organization registers cited across this material record.
Copper Development Association Inc.CDA Alloy C17500 Property & Specification Profile
AUTHORITATIVE BODY
Copper Development Association authoritative technical reference profile for C17500 Beryllium Copper (Alloy 10).
Issuing Body: Copper Development Association (CDA)View Source Record ↗
Copper Development Association Inc.CDA UNS Standard Designations Register (C17500)
AUTHORITATIVE BODY
Unified Numbering System (UNS) designation registration register confirming active C17500 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.