spore: profile
id: beryllium-copper
spore_version: 0.2
family: copper-alloys
name: Beryllium copper
abbreviation: BeCu
role: high-strength, non-magnetic conductive spring alloy
category: metals
type: copper-alloys
summary: |
  Beryllium copper C17200 (CuBe2, Alloy 25) is a copper alloy with 1.80 to 2.00 wt% beryllium that is sold age-hardened for strength. Materion gives a 0.2% offset yield strength of 1000 to 1210 MPa in the AT temper and 1100 to 1380 MPa in the HT temper for thin sections, an electrical conductivity of 25 to 30 %IACS and a density of 8.36 g/cm3. The alloy is non-magnetic and non-sparking. Its main hazard is beryllium dust and fume: inhalation can cause chronic beryllium disease, and the legal exposure limits are very low.
best_for: High strength with useful conductivity and non-magnetic behaviour in springs, bushings, bearings and connectors, once beryllium exposure is controlled
weakest_at: 'Health: beryllium dust, mist and fume are a serious inhalation hazard. Strength also depends on temper, since annealed stock yields at only 130 to 250 MPa'
identity:
  formula: Cu with 1.80 to 2.00 wt% Be, 0.20 wt% minimum Ni plus Co, and 0.6 wt% maximum Ni plus Co plus Fe; UNS C17200 (CuBe2, Alloy 25)
  source: materion-rodbar
  where: Chemical composition table, row C17200 (Beryllium 1.80 to 2.00, Nickel plus Cobalt 0.20 min, Nickel plus Cobalt plus Iron 0.6 max, Copper balance). The same composition is printed in the Aircraft Materials AMS 4533 sheet (Be 1.8-2.0, Co 0.2 min).
  designations:
    - system: UNS
      code: C17200
      source: materion-rodbar
      where: Industry standards and specifications line, first entry C17200; title line Alloy 25 (C17200) Rod and Bar
    - system: EN name
      code: CW101C
      source: harald-cube2
      where: 'Designations line: EN CW101C, CW101C'
    - system: EN
      code: '2.1247'
      source: harald-cube2
      where: 'Designations line: W.Nr. 2.1247'
    - system: Trade name
      code: CuBe2
      source: harald-cube2
      where: 'Designations line: CuBe2'
    - system: Trade name
      code: Alloy 25
      source: materion-rodbar
      where: 'Title line: Alloy 25 (C17200) Rod and Bar'
    - system: CDA
      code: '172'
      source: aircraft-ams4533
      where: 'Page title: Beryllium Copper Alloy 25 (UNS C17200 / CDA 172); composition table column CDA 172'
    - system: ASTM
      code: B196
      note: rod and bar
      source: materion-rodbar
      where: 'Industry standards and specifications line: ASTM B-196'
    - system: ASTM
      code: B643
      note: tube
      source: materion-tube
      where: 'Industry standards and specifications line: ASTM B643'
    - system: AMS
      code: '4533'
      note: rod and bar
      source: materion-rodbar
      where: 'Industry standards and specifications line: AMS 4533'
    - system: AMS
      code: '4535'
      note: tube
      source: materion-tube
      where: 'Industry standards and specifications line: AMS 4535'
    - system: SAE
      code: J461
      source: materion-rodbar
      where: 'Industry standards and specifications line: SAE J 461'
    - system: JIS
      code: H3270
      source: materion-rodbar
      where: 'Industry standards and specifications line: JIS H3270'
tags:
  environments: []
  applications:
    - mechanisms
    - electronics-and-chips
properties:
  - benchmark: density
    label: Density, C17200 age-hardened
    value: 8.36
    unit: g/cm3
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: precipitation age-hardened (heat treated)
      unit_in_source: 0.302 lb/in3
      before_heat_treatment: 8.30 g/cm3 (0.300 lb/in3), as a note in the same table
    method: Value printed in a Materion datasheet for the age-hardened condition
    status: ground
    source: materion-rodbar
    where: Physical properties table, column Density, footnote **
  - benchmark: melting_point
    label: Melting point (solidus), C17200
    value: 870
    unit: °C
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      unit_in_source: 1600 °F
      property_type: solidus
    method: Value printed in a Materion datasheet
    status: ground
    source: materion-rodbar
    where: Physical properties table, column Melting Point (Solidus)
  - benchmark: elastic_modulus
    label: Modulus of elasticity, C17200 age-hardened
    value: 131
    unit: GPa
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: precipitation age-hardened (heat treated)
      unit_in_source: 19,000 ksi
    method: Value printed in a Materion datasheet
    status: ground
    source: materion-rodbar
    where: Physical properties table, column Elastic Modulus
  - benchmark: electrical_conductivity
    label: Electrical conductivity, C17200 age-hardened
    value: 25
    value_high: 30
    bound: range
    unit: '%IACS'
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: precipitation age-hardened (heat treated)
      unit_in_source: 25 - 30% IACS
    method: Range printed in a Materion datasheet
    status: ground
    source: materion-rodbar
    where: Physical properties table, column Electrical Conductivity/Resistivity, first line
  - benchmark: electrical_resistivity
    label: Electrical resistivity, C17200 age-hardened
    value: 5.8
    value_high: 6.9
    bound: range
    unit: μΩ-cm
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: precipitation age-hardened (heat treated)
      unit_in_source: 5.8 - 6.9 μΩ - cm
    method: Range printed in a Materion datasheet
    status: ground
    source: materion-rodbar
    where: Physical properties table, column Electrical Conductivity/Resistivity, second line
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 25 °C, C17200 age-hardened
    value: 105
    unit: W/(m·K)
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: precipitation age-hardened (heat treated)
      temperature: 25 °C
      unit_in_source: 60 BTU/ft hr °F
    method: Value printed in a Materion datasheet
    status: ground
    source: materion-rodbar
    where: Physical properties table, column Thermal Conductivity (25 °C), metric line
  - benchmark: cte
    label: Coefficient of thermal expansion, C17200
    value: 17.5
    unit: ppm/K
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temperature: not stated in the table
      unit_in_source: 17.5 x 10-6 m/m °C
    method: Value printed in a Materion datasheet, metric line
    status: ground
    source: materion-rodbar
    where: Physical properties table, column Thermal Expansion Coefficient, metric line
  - benchmark: relative_magnetic_permeability
    label: Relative magnetic permeability, C17200 age-hardened
    value: 1.0006
    bound: upper
    unit: '-'
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: precipitation age-hardened (heat treated)
      unit_in_source: < 1.0006
    method: Upper limit printed in a Materion tube datasheet
    status: ground
    source: materion-tube
    where: Physical properties table, column Relative Magnetic Permeability
  - benchmark: yield_strength
    label: Yield strength 0.2% offset, annealed temper A (TB00)
    value: 130
    value_high: 250
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: A (TB00), solution annealed
      size: 0.030 to 14 in (0.76 to 356 mm) diameter or thickness
      unit_in_source: 20 - 35 ksi
    method: Range printed in a Materion datasheet, mechanical properties table
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row A (TB00), column 0.2% Offset Yield Strength, MPa
  - benchmark: yield_strength
    label: Yield strength 0.2% offset, hard temper H (TD04)
    value: 520
    value_high: 720
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: H (TD04), hard
      size: 0.030 to 0.375 in (0.76 to 9.5 mm) diameter or thickness
      unit_in_source: 75 - 105 ksi
    method: Range printed in a Materion datasheet, mechanical properties table
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row H (TD04) 0.030 - 0.375, column 0.2% Offset Yield Strength, MPa
  - benchmark: yield_strength
    label: Yield strength 0.2% offset, age-hardened temper AT (TF00)
    value: 1000
    value_high: 1210
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: AT (TF00), precipitation age-hardened
      size: 0.030 to 3 in (0.76 to 76 mm) diameter or thickness
      heat_treatment: 600 to 675 °F (315 to 357 °C), after 3 hours
      unit_in_source: 145 - 175 ksi
    method: Range printed in a Materion datasheet, mechanical properties table
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row AT (TF00) 0.030 - 3, column 0.2% Offset Yield Strength, MPa
  - benchmark: yield_strength
    label: Yield strength 0.2% offset, age-hardened temper HT (TH04)
    value: 1100
    value_high: 1380
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: HT (TH04), precipitation age-hardened
      size: 0.030 to 0.375 in (0.76 to 9.5 mm) diameter or thickness
      heat_treatment: 600 to 675 °F (315 to 357 °C), after 2 to 3 hours
      unit_in_source: 160 - 200 ksi
    method: Range printed in a Materion datasheet, mechanical properties table
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row HT (TH04) 0.030 - 0.375, column 0.2% Offset Yield Strength, MPa
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, annealed temper A (TB00)
    value: 410
    value_high: 590
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: A (TB00), solution annealed
      size: 0.030 to 14 in (0.76 to 356 mm) diameter or thickness
      unit_in_source: 60 - 85 ksi
    method: Range printed in a Materion datasheet, mechanical properties table
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row A (TB00), column Ultimate Tensile Strength, MPa
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, hard temper H (TD04)
    value: 620
    value_high: 900
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: H (TD04), hard
      size: 0.030 to 0.375 in (0.76 to 9.5 mm) diameter or thickness
      unit_in_source: 90 - 130 ksi
    method: Range printed in a Materion datasheet, mechanical properties table
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row H (TD04) 0.030 - 0.375, column Ultimate Tensile Strength, MPa
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, age-hardened temper AT (TF00)
    value: 1140
    value_high: 1380
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: AT (TF00), precipitation age-hardened
      size: 0.030 to 3 in (0.76 to 76 mm) diameter or thickness
      heat_treatment: 600 to 675 °F (315 to 357 °C), after 3 hours
      unit_in_source: 165 - 200 ksi
    method: Range printed in a Materion datasheet, mechanical properties table
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row AT (TF00) 0.030 - 3, column Ultimate Tensile Strength, MPa
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, age-hardened temper HT (TH04)
    value: 1280
    value_high: 1550
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: HT (TH04), precipitation age-hardened
      size: 0.030 to 0.375 in (0.76 to 9.5 mm) diameter or thickness
      heat_treatment: 600 to 675 °F (315 to 357 °C), after 2 to 3 hours
      unit_in_source: 185 - 225 ksi
    method: Range printed in a Materion datasheet, mechanical properties table
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row HT (TH04) 0.030 - 0.375, column Ultimate Tensile Strength, MPa
  - benchmark: elongation
    label: Elongation, annealed temper A (TB00)
    value: 20
    value_high: 75
    bound: range
    unit: '%'
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: A (TB00), solution annealed
      size: 0.030 to 14 in (0.76 to 356 mm) diameter or thickness
    method: Range printed in a Materion datasheet, mechanical properties table (percent column)
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row A (TB00), column Elongation, Percent
  - benchmark: elongation
    label: Elongation, hard temper H (TD04)
    value: 8
    value_high: 30
    bound: range
    unit: '%'
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: H (TD04), hard
      size: 0.030 to 0.375 in (0.76 to 9.5 mm) diameter or thickness
    method: Range printed in a Materion datasheet, mechanical properties table (percent column)
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row H (TD04) 0.030 - 0.375, column Elongation, Percent
  - benchmark: elongation
    label: Elongation, age-hardened temper AT (TF00)
    value: 4
    value_high: 10
    bound: range
    unit: '%'
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: AT (TF00), precipitation age-hardened
      size: 0.030 to 3 in (0.76 to 76 mm) diameter or thickness
      heat_treatment: 600 to 675 °F (315 to 357 °C), after 3 hours
    method: Range printed in a Materion datasheet, mechanical properties table (percent column)
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row AT (TF00) 0.030 - 3, column Elongation, Percent
  - benchmark: elongation
    label: Elongation, age-hardened temper HT (TH04)
    value: 2
    value_high: 9
    bound: range
    unit: '%'
    scope: material
    conditions:
      grade: C17200 (Alloy 25)
      temper: HT (TH04), precipitation age-hardened
      size: 0.030 to 0.375 in (0.76 to 9.5 mm) diameter or thickness
      heat_treatment: 600 to 675 °F (315 to 357 °C), after 2 to 3 hours
    method: Range printed in a Materion datasheet, mechanical properties table (percent column)
    status: ground
    source: materion-rodbar
    where: Mechanical properties table, row HT (TH04) 0.030 - 0.375, column Elongation, Percent
corrosion:
  - environment: Seawater and down-hole oil and gas environments
    headline: Wikipedia says C17200 has effective corrosion-resistant properties in harsh conditions such as seawater and down-hole environments.
    effect: The same page says the alloy withstands sulphide and chloride stress corrosion cracking and resists the effects of carbon dioxide and hydrogen embrittlement. No corrosion rate, test duration or specimen was read in any source.
    rating: low
    conditions:
      basis: Qualitative statements in a web encyclopaedia; no test data read
    source: wikipedia-becu
    where: Corrosion resistance paragraph
  - environment: General service
    headline: Materion and voestalpine both list corrosion resistance among the alloy's properties, with no rate or test condition.
    effect: Materion names high fatigue strength and resistance to wear, corrosion, galling and stress relaxation. voestalpine says the alloy has excellent conductivity and corrosion resistance and is suited to connectors and harsh-environment components.
    rating: low
    conditions:
      basis: Manufacturer and supplier statements; no test data read
    source: materion-rodbar
    where: Overview paragraph (first paragraph of the rod and bar datasheet)
risks:
  hazards:
    - text: Beryllium dust, mist and fume are the main hazard. Inhalation can cause chronic beryllium disease, which restricts the exchange of oxygen between the lungs and the bloodstream.
      ghs: []
      source: wikipedia-beryllium
      where: Toxicity, Inhalation section
    - text: Materion warns that processing beryllium-containing alloys poses a health risk if safe practices are not followed, and that inhalation of airborne beryllium can cause serious lung diseases in some individuals.
      ghs: []
      source: materion-rodbar
      where: Health and Safety section
    - text: 'US occupational limits for airborne beryllium: an 8-hour time-weighted average of 0.2 µg/m3, a 15-minute short-term limit of 2.0 µg/m3, and an action level of 0.1 µg/m3 as an 8-hour TWA.'
      ghs: []
      source: cornell-1910-1024
      where: 29 CFR 1910.1024, paragraph (c)(1) time-weighted average PEL, paragraph (c)(2) short-term exposure limit, and paragraph (b) definition of action level
    - text: The GHS box for elemental beryllium lists signal word Danger and hazard statements H301, H315, H317, H319, H330, H335, H350i and H372. These describe the element, not this alloy; the alloy's own safety data sheet was not read.
      ghs:
        - H301
        - H315
        - H317
        - H319
        - H330
        - H335
        - H350i
        - H372
      source: wikipedia-beryllium
      where: GHS labelling box in the infobox, Hazards
    - text: Wikipedia says IARC lists beryllium and its compounds as Category 1 carcinogens, and that the NTP also lists beryllium as a carcinogen.
      ghs: []
      source: wikipedia-beryllium
      where: Toxicity, Inhalation section (IARC statement)
  failure_risks:
    - mode: Low strength in the annealed temper
      trigger: Using A (TB00) stock where a high-strength part is needed without an age-hardening step
      consequence: Annealed rod and bar has a 0.2% offset yield strength of 130 to 250 MPa, against 1000 to 1380 MPa for the aged AT and HT tempers (thin sections).
      severity: moderate
      source: materion-rodbar
      where: Mechanical properties table, rows A (TB00), AT (TF00) and HT (TH04)
    - mode: Properties outside the stated ageing window
      trigger: Age-hardening outside 600 to 675 °F (315 to 357 °C) or for a time other than the printed one
      consequence: Materion gives its properties for the precipitation age-hardened condition only, so a part aged outside the printed window is outside the quoted values. The datasheet gives no measured consequence of that deviation.
      severity: moderate
      source: materion-rodbar
      where: Physical properties footnote (*) and Heat Treatment Required column of the mechanical properties table
  side_effects:
    - text: The USGS says copper alloys with nickel and silicon, tin, titanium or other alloying elements, and phosphor bronze, may replace beryllium-copper, but the substitution can result in substantially reduced performance.
      affects: Choice of substitute alloy in a design
      source: usgs-mcs2026-beryllium
      where: Substitutes paragraph
  handling:
    - text: Read and follow the Safety Data Sheet and Materion's beryllium safety guidance before working with this material.
      source: materion-rodbar
      where: Health and Safety section
    - text: Specify the temper and size. Materion says properties may vary by diameter (rod) or thickness (bar) and specifies the physical and mechanical values only for the precipitation age-hardened condition.
      source: materion-rodbar
      where: Physical properties footnote (*), and mechanical properties footnote (*)
  mitigations: []
uses:
  - application: mechanisms
    device: Bushings, bearings and springs
    example: Materion lists bushings and bearings for aircraft among the typical applications of its tube. Wikipedia lists springs, spring wire and load cells as uses where the alloy must keep its shape under repeated stress.
    source: materion-tube
    where: Typical applications paragraph (tube datasheet); Uses section of wikipedia-becu
  - application: electronics-and-chips
    device: Circular and coaxial connectors, test probes and compression contacts
    example: Materion lists these as typical applications of its rod and bar, citing high fatigue strength and resistance to wear and stress relaxation. voestalpine says the alloy is non-magnetic and non-sparking and suited to connectors.
    source: materion-rodbar
    where: Overview paragraph; voestalpine C17200 page (voestalpine-c17200)
supply:
  - subject: Beryllium (mine production)
    producers:
      - country: United States
        share_percent: 53.5
        year: 2025
      - country: Brazil
        share_percent: 18.6
        year: 2025
      - country: China
        share_percent: 17.9
        year: 2025
      - country: Nigeria
        share_percent: 9.3
        year: 2025
    critical_lists: []
    recycling: 'USGS: recovered beryllium from new and old scrap may account for as much as 20% to 25% of total beryllium consumption. The leading US producer recovered about 40% of the beryllium content of new and old beryllium alloy scrap under its programme.'
    substitutes:
      - 'USGS: copper alloys with nickel and silicon, tin, titanium or other alloying elements, and phosphor bronze, may be substituted for beryllium-copper alloys, with reduced performance.'
    source: usgs-mcs2026-beryllium
    where: World Mine Production and Reserves table, 2025e world total (rounded) 430 t of beryllium content; shares calculated by Space Mushroom from the country values 230, 80, 77 and 40 over that total. Import sources 2021 to 24 (Kazakhstan 31%, Latvia 25%, Japan 19%, Germany 5%, other 20%) in Domestic Production and Use. Recycling and Substitutes sections.
documents:
  - title: Materion Alloy 25 (C17200) Rod and Bar Data Sheet, DS-AM-23 (2020), hosted by voestalpine
    type: datasheet
    url: https://voestalpine.com/specialtymetals/nam/app/uploads/sites/255/2024/07/Alloy-25-C17200-Rod-and-Bar-Data-Sheet.pdf
    year: 2020
  - title: Materion Alloy 25 (C17200) Tube Data Sheet, hosted by voestalpine
    type: datasheet
    url: https://voestalpine.com/specialtymetals/nam/app/uploads/sites/255/2024/07/Alloy-25-C17200-Tube-Data-Sheet.pdf
  - title: 'USGS Mineral Commodity Summaries 2026: Beryllium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-beryllium.pdf
    year: 2026
  - title: Aircraft Materials, Beryllium Copper Alloy 25 (UNS C17200 / CDA 172) technical data sheet, AMS 4533
    type: datasheet
    url: https://aircraftmaterials.com/data/copper/ams4533.html
  - title: 29 CFR 1910.1024 Beryllium, Cornell Legal Information Institute
    type: standard
    url: https://www.law.cornell.edu/cfr/text/29/1910.1024
  - title: Beryllium copper, Wikipedia
    type: report
    url: https://en.wikipedia.org/wiki/Beryllium_copper
  - title: Beryllium, Wikipedia (toxicity and GHS box)
    type: report
    url: https://en.wikipedia.org/wiki/Beryllium
  - title: Harald Pihl, Copper Alloy 25 / CuBe2 (CW101C) product page
    type: report
    url: https://www.haraldpihl.com/en/products/copper-alloys/cube2-cw101c/
  - title: voestalpine Specialty Metals, C17200 BeCu / Alloy 25 product page
    type: report
    url: https://www.voestalpine.com/specialtymetals/nam/en/materials/c17200-becu-alloy-25/
gaps:
  - Outgassing, atomic-oxygen, radiation and thermal-vacuum test results for beryllium copper were not found in any source opened in this run; the profile has no space-environment data.
  - The alloy's own safety data sheet was not read. The hazard entries use OSHA's regulation text, Wikipedia's toxicity section and the GHS box for elemental beryllium, which describes the element and not C17200.
  - NIOSH IDLH and REL values for beryllium were not entered. The CDC page returned HTTP 403, and the only other copy found was an unofficial 1994 archive, so it was not used.
  - 'PubChem records were not used: the site returned a bot-check page.'
  - The USGS 2026 beryllium summary does not state a critical minerals list, so critical_lists is empty.
  - 'Hardness values are not entered: the datasheets read in this run do not print a hardness, and the Wikipedia Rockwell figures are not from a datasheet.'
  - Electrical conductivity and thermal conductivity are given for the age-hardened condition only; values for the annealed temper were not printed in the datasheets read.
  - Fatigue strength, stress-relaxation, galling and cold-welding figures were not found as numbers; Materion names these properties without values.
  - Cryogenic behaviour and radiation effects were not looked up.
  - Wikipedia gives a solidus of 866 °C in its own text. The Materion value of 870 °C from the datasheet is used instead, and the Wikipedia value is not entered.
  - relative_magnetic_permeability is a snake_case name that is not in the canonical property list, so the canonical unit conversion may not apply.
  - The voestalpine page states NACE MR0175 and ISO 15156 sour-service listings for C17200. These were not checked against the standards and are not entered.
  - Density of the annealed (before heat treatment) condition is kept in the conditions field as printed; no separate property row was added.
sources:
  materion-rodbar:
    title: Materion Alloy 25 (C17200) Rod and Bar Data Sheet, DS-AM-23 (2020)
    id: Materion Performance Alloys and Composites, DS-AM-23, copyright 2020
    url: https://voestalpine.com/specialtymetals/nam/app/uploads/sites/255/2024/07/Alloy-25-C17200-Rod-and-Bar-Data-Sheet.pdf
    year: 2020
    kind: datasheet
    license: Manufacturer datasheet (cited, not reproduced)
  materion-tube:
    title: Materion Alloy 25 (C17200) Tube Data Sheet
    id: Materion Performance Alloys and Composites, tube data sheet
    url: https://voestalpine.com/specialtymetals/nam/app/uploads/sites/255/2024/07/Alloy-25-C17200-Tube-Data-Sheet.pdf
    kind: datasheet
    license: Manufacturer datasheet (cited, not reproduced)
  usgs-mcs2026-beryllium:
    title: 'Mineral Commodity Summaries 2026: Beryllium'
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-beryllium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  aircraft-ams4533:
    title: Beryllium Copper Alloy 25 (UNS C17200 / CDA 172) Technical Data Sheet, Aircraft Materials
    id: AMS 4533, CDA 172
    url: https://aircraftmaterials.com/data/copper/ams4533.html
    kind: datasheet
    license: Supplier data sheet (cited, not reproduced)
  cornell-1910-1024:
    title: 29 CFR 1910.1024 Beryllium, Cornell Legal Information Institute
    url: https://www.law.cornell.edu/cfr/text/29/1910.1024
    kind: standard
    license: US federal regulation (public domain)
  wikipedia-becu:
    title: Beryllium copper, Wikipedia
    url: https://en.wikipedia.org/wiki/Beryllium_copper
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  wikipedia-beryllium:
    title: Beryllium, Wikipedia
    url: https://en.wikipedia.org/wiki/Beryllium
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  harald-cube2:
    title: Harald Pihl, Copper Alloy 25 / CuBe2 (CW101C) product page
    url: https://www.haraldpihl.com/en/products/copper-alloys/cube2-cw101c/
    kind: web
    license: Supplier web page (cited, not reproduced)
  voestalpine-c17200:
    title: voestalpine Specialty Metals, C17200 BeCu / Alloy 25 product page
    url: https://www.voestalpine.com/specialtymetals/nam/en/materials/c17200-becu-alloy-25/
    kind: web
    license: Supplier web page (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-10-25'
review:
  status: draft
  method: assistant
  checked_values: 20
  unreachable: 1
  caveats: 5
  note: 'Values were read by an AI assistant on 2026-10-25 from the Materion datasheets (rod and bar, tube), extracted from the PDFs. Unreachable: the CDC NIOSH IDLH page (HTTP 403). Caveats: all mechanical and physical values are Materion''s nominal values for age-hardened stock of stated sizes, not minimum specification values; the Wikipedia corrosion and toxicity statements are qualitative; the OSHA limits come from the regulation text; the GHS box describes elemental beryllium, not the alloy; no space-environment data were found.'
story:
  risk_groups:
    - title: For people
      lead: The alloy itself is a solid copper alloy, but processing it can release beryllium dust or fume, and that is the serious hazard.
      level: 2
      verdict: Serious inhalation hazard
      points:
        - label: Lungs
          line: Inhaled beryllium can cause chronic beryllium disease, which restricts the exchange of oxygen between the lungs and the bloodstream. Materion says processing beryllium-containing alloys poses a health risk without safe practice.
        - label: Limits
          line: US law sets an 8-hour average limit of 0.2 µg/m3 and a 15-minute limit of 2.0 µg/m3, with an action level of 0.1 µg/m3.
        - label: Carcinogen
          line: IARC lists beryllium and its compounds as Category 1 carcinogens, according to Wikipedia.
    - title: If it fails
      lead: These failure routes come from the datasheets and are about temper and heat treatment, not corrosion failure.
      points:
        - label: Soft stock
          line: Annealed rod and bar yields at 130 to 250 MPa, against 1000 to 1380 MPa for the aged AT and HT tempers.
        - label: Wrong ageing
          line: Materion gives its values only for the precipitation age-hardened condition, so a part aged outside the printed window is outside the quoted properties.
    - title: Handling and storage
      points:
        - label: Follow the sheet
          line: Read the Safety Data Sheet and Materion's beryllium safety guidance before working with the material.
        - label: Specify the temper
          line: Properties vary with diameter or thickness, so state the temper and size on every order.
  why: Beryllium copper is used where a copper alloy must be strong and springy. Materion gives it as the highest-strength copper alloy, with conductivity considerably higher than other high-strength copper alloys, and it is non-magnetic and non-sparking. Its strength comes from age-hardening with 1.80 to 2.00 wt% beryllium, so the same alloy can be soft and easy to form in one temper and very strong in another. The price of that strength is beryllium, whose dust and fume are a serious health hazard.
  uses:
    - where: Bearings and bushings
      line: Materion lists bushings and bearings for aircraft among the typical applications of its tube, and Wikipedia lists springs and load cells as uses where the alloy must keep its shape under repeated stress.
    - where: Connectors and contacts
      line: Materion lists circular and coaxial connectors, test probes and compression contacts among typical rod and bar applications.
  can_do:
    - label: Strength when aged
      value: 1000 to 1380 MPa yield
      benchmark: yield_strength
      line: In the AT and HT tempers, the 0.2% offset yield strength is 1000 to 1210 MPa (AT) and 1100 to 1380 MPa (HT) for thin sections, according to Materion.
    - label: Conductivity
      value: 25 to 30 %IACS
      benchmark: electrical_conductivity
      line: Materion gives 25 to 30 %IACS for the age-hardened condition, against 5.8 to 6.9 µΩ-cm resistivity.
    - label: Stiffness
      value: 131 GPa
      benchmark: elastic_modulus
      line: The modulus of elasticity is 131 GPa (19,000 ksi) in the age-hardened condition.
    - label: Weight
      value: 8.36 g/cm3
      benchmark: density
      line: Density is 8.36 g/cm3 after heat treatment and 8.30 g/cm3 before it, per Materion's footnote.
    - label: Non-magnetic
      value: < 1.0006
      benchmark: relative_magnetic_permeability
      line: The tube datasheet gives a relative magnetic permeability below 1.0006.
  compare: Materion describes C17200 as having the highest strength of any copper alloy, with electrical and thermal conductivity considerably greater than other high-strength copper alloys. The USGS says copper alloys with nickel and silicon, tin, titanium or phosphor bronze may replace beryllium-copper, but with reduced performance. Read the rows below as values for this alloy only.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Yield strength
      benchmark: yield_strength
    - label: Electrical conductivity
      benchmark: electrical_conductivity
  handling:
    - Specify the temper and size, because yield strength runs from 130 to 250 MPa in the annealed condition up to 1380 MPa when aged.
    - Follow the Safety Data Sheet and treat all machining, grinding and fume as a beryllium exposure risk.
    - Keep exposure below the OSHA limits of 0.2 µg/m3 (8-hour TWA) and 2.0 µg/m3 (15-minute short-term).
  good_for:
    - Springs, bushings and bearings that need high strength and a non-magnetic, non-sparking alloy
    - Connectors, contacts and test probes that need strength together with conductivity
    - 'Recycling: the USGS says scrap may supply as much as 20% to 25% of beryllium consumption'
  watch_out:
    - 'Beryllium dust, mist and fume: inhalation can cause chronic beryllium disease, and IARC lists beryllium as a Category 1 carcinogen'
    - 'Temper matters: annealed stock is soft, and the high strengths need the printed ageing step'
    - 'Supply is concentrated: the United States, Brazil, China and Nigeria produced about 99% of 2025 mine output in the USGS table (shares computed from the table, with rounded world total)'
    - No space-environment test data were found for this alloy
  verdict: Beryllium copper C17200 is a strong, conductive, non-magnetic copper alloy whose age-hardened tempers reach 1000 to 1380 MPa yield strength and 25 to 30 %IACS conductivity. Its beryllium content makes dust and fume a serious health hazard, and its strength depends on the temper chosen. This profile has no space-environment data.
  recipe:
    line: C17200 is a copper alloy (Cu) with 1.80 to 2.00 wt% beryllium, plus small amounts of nickel and cobalt. It is sold in a solution-annealed (A) condition and age-hardened to its high-strength tempers at 600 to 675 °F (315 to 357 °C) (Materion).
    parts:
      - name: Beryllium
        symbol: Be
        share: 1.80 to 2.00 wt%
        role: The age-hardening element. Materion calls the alloy precipitation age-hardened, which gives the high-strength tempers.
      - name: Nickel plus cobalt
        symbol: Ni+Co
        share: 0.20 wt% minimum
        role: Minor additions. Materion sets a maximum of 0.6 wt% for nickel, cobalt and iron together.
      - name: Copper
        symbol: Cu
        share: balance
        role: The matrix and the main metal.