spore: profile
id: alloy-52
spore_version: 0.2
family: controlled-expansion-alloys
name: Alloy 52 (UNS N14052, iron-nickel glass-sealing alloy)
abbreviation: Alloy 52
role: controlled-expansion glass-sealing alloy
category: metals
type: nickel-superalloys
summary: |
  Alloy 52 is an iron-nickel alloy, UNS N14052 and ASTM F30, developed for glass-to-metal seals. The Ulbrich wire datasheet gives a density of 8.30 g/cm3 and a melting point of 1430°C, and a mean coefficient of thermal expansion of 9.8 µm/m-°C over 25 to 450°C. The sources disagree on nickel content: Ulbrich prints "Nickel: 50.5 nom", while JLC Electromet prints "Ni: 52" and Elan prints "52% Nickel, Balance Iron". No corrosion test result was found in the sources read.
best_for: Matching the expansion of soft glass and some ceramics in glass-to-metal seals, such as magnetic reed switch housings
weakest_at: 'Corrosion and oxidation performance: no test data were found, and the Ulbrich datasheet only refers readers to NACE'
identity:
  formula: Iron-nickel alloy, nominal nickel 50.5 % with iron balance, per Ulbrich (other sources print 52 % nickel; see story.recipe)
  source: ulbrich-52
  where: Title block (Alloy 52, UNS N14052, ASTM F30) and Chemistry Typical table
  designations:
    - system: UNS
      code: N14052
      source: ulbrich-52
      where: 'Title block: Alloy 52, UNS N14052'
    - system: ASTM
      code: F30
      source: ulbrich-52
      where: 'Title block: ASTM F30'
    - system: EN
      code: '2.4478'
      source: aperam-n52
      where: 'Norms list for IMPHY N52: 2.4478'
    - system: DIN
      code: '17745'
      note: standard number printed under the norms for this product
      source: aperam-n52
      where: Norms list for IMPHY N52
tags:
  applications:
    - electronics-and-chips
properties:
  - benchmark: density
    label: Density, Alloy 52 wire (Ulbrich)
    value: 8.3
    unit: g/cm3
    scope: material
    conditions:
      form: wire (Ulbrich offers shaped, flat, square, round and fine wire)
      temperature: not stated
      note_in_source: all data are considered typical values only
    method: Typical value printed in a wire supplier datasheet (copyright January 2014, revision 6.1.2015)
    status: ground
    source: ulbrich-52
    where: 'Physical Properties, Density: 0.30 lb/in3, 8.30 g/cm3'
  - benchmark: melting_point
    label: Melting point, Alloy 52 wire (Ulbrich)
    value: 1430
    unit: °C
    scope: material
    conditions:
      pressure: not stated
      unit_in_source: 2600°F
    method: Value printed in a wire supplier datasheet
    status: ground
    source: ulbrich-52
    where: 'Physical Properties, Melting Point: 2600°F (1430°C)'
  - benchmark: melting_point
    label: Melting point, approximate (Hamilton Precision Metals)
    value: 1425
    unit: °C
    scope: material
    conditions:
      pressure: not stated
      qualifier: printed as approximate
    method: Approximate value printed on a metals supplier product page
    status: ground
    note: Differs from the Ulbrich value of 1430°C. The page prints the value as approximate.
    source: hpm-ni52
    where: Physical Properties, Melting Point (Approx.) 1425°C
  - benchmark: cte
    label: Mean coefficient of thermal expansion, 25 to 450 °C (Ulbrich)
    value: 9.8
    unit: µm/m-°C
    scope: material
    conditions:
      temperature_range: 25 to 450 °C (printed as 77-842°F (25-450°C))
      temper: not stated
      unit_in_source: 5.4 µin/in-°F
    method: Mean value printed in a wire supplier datasheet
    status: ground
    note: The sheet says the rate is virtually constant up to about 565 °C (printed as 1050°F (565°C)). The imperial value 5.4 is the same quantity in µin/in-°F.
    source: ulbrich-52
    where: 'Physical Properties, Mean Coefficient of Thermal Expansion, 77-842°F (25-450°C): 5.4 (9.8)'
  - benchmark: cte
    label: Mean coefficient of thermal expansion, 20 to 100 °C, annealed (JLC Electromet)
    value: 10.3
    unit: µm/m-°C
    scope: material
    conditions:
      temperature_range: 20 to 100 °C
      temper: annealed
    method: Mean value printed in a metals supplier datasheet
    status: ground
    source: jlc-52
    where: 'Mean Coefficient of Thermal Expansion in Annealed Condition (µm/m-°C), temperature range 20-100 °C: 10.3'
  - benchmark: cte
    label: Mean coefficient of thermal expansion, 20 to 400 °C, annealed (JLC Electromet)
    value: 10.1
    unit: µm/m-°C
    scope: material
    conditions:
      temperature_range: 20 to 400 °C
      temper: annealed
    method: Mean value printed in a metals supplier datasheet
    status: ground
    source: jlc-52
    where: 'Mean Coefficient of Thermal Expansion in Annealed Condition (µm/m-°C), temperature range 20-400 °C: 10.1'
  - benchmark: cte
    label: Mean coefficient of thermal expansion, 20 to 500 °C, annealed (JLC Electromet)
    value: 9.9
    unit: µm/m-°C
    scope: material
    conditions:
      temperature_range: 20 to 500 °C
      temper: annealed
    method: Mean value printed in a metals supplier datasheet
    status: ground
    source: jlc-52
    where: 'Mean Coefficient of Thermal Expansion in Annealed Condition (µm/m-°C), temperature range 20-500 °C: 9.9'
  - benchmark: electrical_resistivity
    label: Electrical resistivity at 20 °C (Ulbrich)
    value: 43
    unit: microhm-cm
    scope: material
    conditions:
      temperature: 68°F (20°C)
      unit_in_source: 258 ohm-cir-mil/ft
    method: Value printed in a wire supplier datasheet
    status: ground
    source: ulbrich-52
    where: 'Physical Properties, Electrical Resistivity, At 68°F (20°C): 258(43)'
  - benchmark: electrical_resistivity
    label: Electrical resistivity at room temperature (Hamilton Precision Metals)
    value: 43
    unit: Microhm·cm
    scope: material
    conditions:
      temperature: room temperature (R.T., as printed)
    method: Value printed in a metals supplier product page
    status: ground
    source: hpm-ni52
    where: Physical Properties, Electrical Resistivity @ R.T. 43 Microhm·cm
  - benchmark: electrical_resistivity
    label: Electrical resistivity at 20 °C (JLC Electromet)
    value: 43
    unit: µΩ-cm
    scope: material
    conditions:
      temperature: 20 °C
    method: Nominal value printed in a metals supplier datasheet
    status: ground
    source: jlc-52
    where: 'Nominal Physical, Electrical & Mechanical Properties (at room temperature), Electrical Resistivity at 20 °C (µΩ-cm): 43'
  - benchmark: thermal_conductivity
    label: Thermal conductivity at room temperature (Hamilton Precision Metals)
    value: 14
    unit: W/m·K
    scope: material
    conditions:
      temperature: room temperature (R.T., as printed)
    method: Value printed on a metals supplier product page
    status: ground
    note: Conflicts with 140 W/m·K printed by Ulbrich for the metric column. This value agrees with the Ulbrich imperial figure of 97 BTU-in/hr-ft2-°F, which converts to about this magnitude. The record does not resolve the conflict.
    source: hpm-ni52
    where: Physical Properties, Thermal Conductivity @ R.T. 14.0 W/m·K
  - benchmark: thermal_conductivity
    label: Thermal conductivity, 20 to 100 °C (Ulbrich, metric column)
    value: 140
    unit: W/m·K
    scope: material
    conditions:
      temperature_range: 68-212°F (20-100°C)
    method: Value printed in a wire supplier datasheet
    status: ground
    note: Conflicts with 14.0 W/m·K from Hamilton Precision Metals. It is the metric column of the same row that prints 97 BTU-in/hr-ft2-°F, so it may be a misprint; this record keeps both as printed.
    source: ulbrich-52
    where: 'Physical Properties, Thermal Conductivity: BTU-in/hr-ft2-°F (W/m·K), 68-212°F (20-100°C): 97(140)'
  - benchmark: thermal_conductivity
    label: Thermal conductivity, 20 to 100 °C (Ulbrich, imperial column)
    value: 97
    unit: BTU-in/hr-ft2-°F
    scope: material
    conditions:
      temperature_range: 68-212°F (20-100°C)
    method: Value printed in a wire supplier datasheet
    status: ground
    note: Printed beside the metric value of 140 W/m·K in the same row.
    source: ulbrich-52
    where: 'Physical Properties, Thermal Conductivity: BTU-in/hr-ft2-°F (W/m·K), 68-212°F (20-100°C): 97(140)'
  - benchmark: curie_temperature
    label: Curie temperature
    value: 510
    unit: °C
    scope: material
    conditions:
      qualifier: printed as approximate
    method: Approximate value printed on a metals supplier product page
    status: ground
    source: hpm-ni52
    where: Physical Properties, Curie Temperature 510°C Approx
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, annealed typical (Ulbrich)
    value: 536
    unit: MPa
    scope: material
    conditions:
      temper: annealed (typical, nominal)
      unit_in_source: 78 KSI nom
    method: Nominal typical value printed in a wire supplier datasheet
    status: ground
    source: ulbrich-52
    where: 'Mechanical Properties at Room Temperature, Annealed Typical, Ultimate Tensile Strength: 78 KSI nom (536 MPa nom)'
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, nominal (JLC Electromet)
    value: 540
    unit: N/mm2
    scope: material
    conditions:
      temper: not stated
      temperature: room temperature (as printed)
    method: Nominal value printed in a metals supplier datasheet
    status: ground
    note: Differs from the Ulbrich annealed typical value of 536 MPa; the JLC page does not state the temper.
    source: jlc-52
    where: 'Nominal Physical, Electrical & Mechanical Properties (at room temperature), Tensile Strength (N/mm²): 540'
  - benchmark: yield_strength
    label: Yield strength, annealed typical (Ulbrich)
    value: 240
    unit: MPa
    scope: material
    conditions:
      temper: annealed (typical, nominal)
      unit_in_source: 35 KSI nom
    method: Nominal typical value printed in a wire supplier datasheet
    status: ground
    source: ulbrich-52
    where: 'Mechanical Properties at Room Temperature, Annealed Typical, Yield Strength: 35 KSI nom (240 MPa nom)'
  - benchmark: elongation
    label: Elongation, annealed typical (Ulbrich)
    value: 30
    unit: '%'
    scope: material
    conditions:
      temper: annealed (typical, nominal)
      gauge_length: not stated
    method: Nominal typical value printed in a wire supplier datasheet
    status: ground
    source: ulbrich-52
    where: 'Mechanical Properties at Room Temperature, Annealed Typical: Elongation: 30% nom'
  - benchmark: elongation
    label: Elongation (JLC Electromet)
    value: 30
    unit: '%'
    scope: material
    conditions:
      gauge_length: 100 mm (L0=100 mm as printed)
      temperature: room temperature (as printed)
    method: Nominal value printed in a metals supplier datasheet
    status: ground
    source: jlc-52
    where: 'Nominal Physical, Electrical & Mechanical Properties, Elongation (% at L0=100 mm): 30'
  - benchmark: hardness
    label: Hardness, annealed typical (Ulbrich)
    value: 73
    unit: Rb
    scope: material
    conditions:
      temper: annealed (typical, nominal)
      scale: Rb as printed
    method: Nominal typical value printed in a wire supplier datasheet
    status: ground
    source: ulbrich-52
    where: 'Mechanical Properties at Room Temperature, Annealed Typical, Hardness: Rb 73 nom'
corrosion:
  - environment: Not stated in the sources read
    headline: No corrosion or oxidation test result was found for Alloy 52 in the sources we read.
    effect: The Ulbrich datasheet's corrosion entry says only to refer to NACE for recommendations. No environment, exposure time or rate is given, so no corrosion rating is recorded.
    rating: unknown
    conditions:
      basis: datasheet entry only; no test
      exposure: not stated
    source: ulbrich-52
    where: Additional Properties, Corrosion Resistance
risks:
  hazards:
    - text: PubChem reports, from aggregated ECHA notifications for nickel (CID 935), signal word Danger, with hazard statements H317 (may cause an allergic skin reaction), H334 (may cause allergy or asthma symptoms or breathing difficulties if inhaled), H341 (suspected of causing genetic defects), H350 (may cause cancer), H351 (suspected of causing cancer), H360F (may damage fertility), H372 (causes damage to organs through prolonged or repeated exposure) and H412 (harmful to aquatic life with long lasting effects).
      ghs:
        - H317
        - H334
        - H341
        - H350
        - H351
        - H360F
        - H372
        - H412
      source: pubchem-ni
      where: GHS Classification, aggregated ECHA entry for nickel (CID 935)
    - text: These are the classifications for nickel, a main constituent of Alloy 52, not for the alloy itself. No safety data sheet for Alloy 52 wire was found in this run.
      ghs: []
      source: pubchem-ni
      where: GHS Classification (scope note by Space Mushroom)
  failure_risks:
    - mode: Loss of magnetic attraction when heated past the Curie temperature
      trigger: Heating above about 510 °C
      consequence: The Hamilton Precision Metals page gives a Curie temperature of 510°C approx and lists magnetic attraction as yes. The source gives no consequence data for seals or reed switches.
      severity: low
      source: hpm-ni52
      where: Physical Properties, Curie Temperature; Magnetic Attraction row
  side_effects: []
  handling:
    - text: Ulbrich states that Alloy 52 is non hardenable by heat treatment.
      source: ulbrich-52
      where: Heat Treatment section
    - text: Ulbrich refers readers to the Specialty Steel Industry of North America (SSINA) guide, Welding of Stainless Steels and Other Joining Methods, for welding.
      source: ulbrich-52
      where: Welding section
    - text: Ulbrich states that all data in its document are typical values only and not recommended for specification, design or engineering purposes.
      source: ulbrich-52
      where: Limitation of Liability and Disclaimer of Warranty
  mitigations: []
uses:
  - application: electronics-and-chips
    device: Magnetic reed switches
    example: Ulbrich lists magnetic reed switches among the applications of Alloy 52 wire.
    source: ulbrich-52
    where: Applications list
  - application: electronics-and-chips
    device: Glass-to-metal seals that need controlled linear expansion
    example: Ulbrich says the alloy was developed for glass-to-metal seals for some of the soft glasses and ceramics, and that its rate of thermal expansion is virtually constant to a temperature of about 1050°F (565°C).
    source: ulbrich-52
    where: Alloy 52 Description and Applications list
  - application: electronics-and-chips
    device: Seal to Elan 13 glass and stainless steel housing
    example: Elan Technology states that No. 52 alloy is an ideal candidate for Elan 13; its page gives no thermal expansion value for the matched glass.
    source: elan-52
    where: Glass recommendations summary
supply:
  - subject: Nickel
    producers:
      - country: Indonesia
        share_percent: 66.7
        year: 2025
      - country: Philippines
        share_percent: 6.9
        year: 2025
      - country: Russia
        share_percent: 5.1
        year: 2025
    critical_lists:
      - list: USGS Final 2025 List of Critical Minerals (nickel printed on the list)
        listed: true
    recycling: 'USGS: nickel recovered from scrap accounted for approximately 60% of apparent consumption in 2025. Most secondary nickel was in the form of nickel content of stainless-steel scrap.'
    substitutes:
      - 'USGS: low-nickel, duplex or ultrahigh-chromium stainless steels have been substituted for austenitic grades in construction; titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments.'
    source: usgs-mcs2026-nickel
    where: 'World Mine Production and Reserves table, mine production 2025e (world total 3,900,000 t; shares calculated by Space Mushroom: 2,600,000, 270,000 and 200,000 t); Recycling; Substitutes'
  - subject: Iron
    producers:
      - country: Australia
        share_percent: 37.7
        year: 2025
      - country: Brazil
        share_percent: 16.2
        year: 2025
      - country: India
        share_percent: 11.9
        year: 2025
    critical_lists:
      - list: USGS Final 2025 List of Critical Minerals (iron and iron ore not listed)
        listed: false
    recycling: Not found in the iron ore chapter read for this profile; iron and steel scrap is covered in a separate USGS chapter that was not opened.
    substitutes: []
    source: usgs-mcs2026-iron-ore
    where: World Mine Production table, usable ore, 2025e (world total 2,600,000 thousand t; shares calculated by Space Mushroom from 980,000, 420,000 and 310,000 thousand t)
documents:
  - title: Alloy 52, UNS N14052, Ulbrich wire datasheet (revision 6.1.2015)
    type: datasheet
    url: https://www.ulbrich.com/uploads/data-sheets/Alloy-52-Wire-UNS-N14052.pdf
    year: 2015
  - title: HPM Ni 52 (UNS N14052) product page, Hamilton Precision Metals
    type: datasheet
    url: https://www.hpmetals.com/products/materials/nickel-strip-foil/hpm-ni-52
  - title: Alloy 52 controlled-expansion alloy page, JLC Electromet
    type: datasheet
    url: https://www.jlcelectromet.com/controlled-expansion-glass-sealing-alloys.html
  - title: Alloy 52 (CFW 100004) datasheet, California Fine Wire
    type: datasheet
    url: https://calfinewire.com/datasheets/100004-alloy52
  - title: IMPHY N52 product page, Aperam
    type: datasheet
    url: https://www.aperam.com/product/imphy-n52/
  - title: Mineral Commodity Summaries 2026, Nickel
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: PubChem compound record for nickel (CID 935), GHS classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Nickel
gaps:
  - No corrosion, oxidation or ageing test result for Alloy 52 was found. The Ulbrich sheet refers to NACE only, and the ASM Alloy Digest entry is behind a paywall.
  - No NASA, ESA or flight result for Alloy 52 was found. The uses listed are terrestrial.
  - Young's modulus is printed by Hamilton Precision Metals as 24 X 106 PSI, with the exponent set as a superscript, so it is left out. No metric modulus was found.
  - Coefficient of thermal expansion values printed with a power of ten (Hamilton Precision Metals 10.0 X 10-6 /°C; California Fine Wire 9.8 x 10-6 in/in ºC) are left out.
  - Thermal conductivity conflicts (14.0 and 140 W/m·K, and 97 BTU-in/hr-ft2-°F) are recorded as printed and not resolved. The California Fine Wire value of 0.132000 W/cm/ºC is left out because it is in a unit this profile does not use.
  - 'Nickel content conflicts: Ulbrich and Hamilton print 50.5 nominal, JLC prints 52, Elan prints 52 %, California Fine Wire prints 50.0000 %, and Aperam prints Fe Ni52 as the nominal grade. The profile uses the Ulbrich nominal.'
  - DIN 1.3923 is printed under the norms of IMPHY N52 on the Aperam page, but the page does not say it is the same grade, so it is not recorded as a designation.
  - No safety data sheet for Alloy 52 wire was found. The hazard entries are for nickel, from PubChem.
  - The California Fine Wire datasheet (100004) was blocked to automated checks, so its density and melting point could not be re-checked and are not recorded. Its nominal composition is printed as 50.0000 % nickel, which conflicts with the other sources.
  - Specific heat (0.115 cal/g in the California Fine Wire sheet), temperature coefficient of resistance and Poisson's ratio each appear in one source and were not recorded.
  - The JLC Electromet page could not be fetched by the automated check (the stored copy is a short error page), so its six values were read in a live fetch but are not machine-checked.
  - Iron recycling is not stated in the iron ore chapter. Supply shares are calculated from production tables and are not printed by USGS.
  - The ASTM F30 standard text was not opened; F30 is recorded only as the designation printed on the Ulbrich and JLC pages.
sources:
  ulbrich-52:
    title: Alloy 52, UNS N14052, Shaped, Flat, Square, Round, Fine Wire (Ulbrich Stainless Steels and Special Metals, Inc.)
    id: Copyright January 2014, revision 6.1.2015
    url: https://www.ulbrich.com/uploads/data-sheets/Alloy-52-Wire-UNS-N14052.pdf
    year: 2015
    kind: datasheet
    license: Manufacturer datasheet, typical values only (cited, not reproduced)
  hpm-ni52:
    title: HPM Ni 52 (UNS N14052), Hamilton Precision Metals product page
    id: HPM Ni 52 • UNS N14052
    url: https://www.hpmetals.com/products/materials/nickel-strip-foil/hpm-ni-52
    kind: datasheet
    license: Supplier web page (cited, not reproduced)
  jlc-52:
    title: Controlled Expansion Glass Sealing Alloys, JLC Electromet
    id: Werkstoff Nr 2.4478; UNS N14052; ASTM F30
    url: https://www.jlcelectromet.com/controlled-expansion-glass-sealing-alloys.html
    kind: datasheet
    license: Supplier web page (cited, not reproduced)
  calfine-52:
    title: Alloy 52 datasheet 100004, California Fine Wire Company
    id: CFW datasheet 100004
    url: https://calfinewire.com/datasheets/100004-alloy52
    kind: datasheet
    license: Supplier web page (cited, not reproduced)
  elan-52:
    title: Glass Recommendations for No. 52 Alloy, Elan Technology
    id: ASTMF-30 (designation as printed)
    url: https://www.elantechnology.com/?p=227
    kind: datasheet
    license: Supplier web page (cited, not reproduced)
  aperam-n52:
    title: IMPHY N52, Aperam product page
    id: 'Norms: 1.3923, 2.4478, UNS N14052, DIN 17745, ASTM F30'
    url: https://www.aperam.com/product/imphy-n52/
    kind: datasheet
    license: Supplier web page (cited, not reproduced)
  usgs-mcs2026-nickel:
    title: Mineral Commodity Summaries 2026, Nickel
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-iron-ore:
    title: Mineral Commodity Summaries 2026, Iron Ore
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-ore.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-critical-2025:
    title: About the 2025 List of Critical Minerals (USGS)
    id: Final 2025 List of Critical Minerals, November 2025
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
    kind: web
    license: public domain (USGS)
  pubchem-ni:
    title: PubChem compound record, Nickel (CID 935), GHS classification (aggregated ECHA data)
    id: CID 935
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Nickel
    year: 2026
    kind: database
    license: public domain (NCBI)
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 20
  unreachable: 3
  caveats: 4
  note: 'Values read by an AI assistant on 2026-11-01 from the pages and PDFs named in each entry (Ulbrich and USGS PDFs extracted with pdftotext). verify-values: 14 of 20 values matched their source text, 0 not found; the JLC Electromet page could not be fetched by the automated check, so its six values were checked by live read only. Unreachable: the suppliersonline Alloy 52 page (HTTP 503), the ASM Alloy Digest (paywalled), and the California Fine Wire datasheet (blocked to automated checks; no values recorded from it). Caveats: values conflict between sources (thermal conductivity, nickel content); all supplier values are typical or nominal; no corrosion data; the supply shares are calculated.'
story:
  recipe:
    line: 'Alloy 52 is a binary iron-nickel alloy. Ulbrich prints "Nickel: 50.5 nom" with "Iron: Balance" and small amounts of other elements, all as maximum limits. The sources do not describe the melting or rolling route beyond Ulbrich''s note that the alloy can be cold rolled to a required temper.'
    parts:
      - name: Nickel
        symbol: Ni
        share_percent: 50.5
        role: 'Main alloying element, set to give the controlled thermal expansion for glass seals. Ulbrich prints "Nickel: 50.5 nom", Hamilton Precision Metals prints "Nickel 50.5%", and JLC prints "Ni: 52".'
      - name: Iron
        symbol: Fe
        role: 'Balance of the alloy, as printed by Ulbrich ("Iron: Balance").'
      - name: Manganese
        symbol: Mn
        role: Minor element. Ulbrich lists only a maximum limit for it, with no nominal value.
      - name: Silicon
        symbol: Si
        role: Minor element. Ulbrich lists only a maximum limit for it, with no nominal value.
  risk_groups:
    - title: For people
      level: 1
      verdict: Nickel classified; alloy not tested
      lead: No safety data sheet for Alloy 52 was found. The hazard classifications available are for nickel, a main constituent.
      points:
        - label: Nickel in the alloy
          line: PubChem's aggregated classification for nickel gives the signal word Danger and includes H317 and H372, among other statements. These describe nickel as a substance, not the alloy.
        - label: Wire and powder
          line: Ulbrich offers wire in several forms, including fine wire. Fine wire and dust from machining should be handled as nickel-containing material, since no alloy-specific data were found.
    - title: If it fails
      lead: The sources give little on failure. The one failure route recorded is a magnetic one.
      points:
        - label: Heating past the Curie temperature
          line: Hamilton Precision Metals gives a Curie temperature of 510°C approx and lists magnetic attraction as yes. Above that temperature the alloy loses its magnetic attraction, and the source gives no consequence data for reed switches.
        - label: Corrosion
          line: Ulbrich's corrosion entry refers readers to NACE and gives no data. Service in corrosive environments is therefore unverified.
    - title: Handling and storage
      points:
        - label: Temper
          line: Ulbrich says Alloy 52 can be cold rolled to produce the temper a customer requires, and that it cannot be hardened by heat treatment.
        - label: Welding
          line: Ulbrich refers readers to the SSINA guide on welding stainless steels and other joining methods.
  why: Alloy 52 is an iron-nickel alloy designed to seal to glass. Ulbrich says it was developed for glass-to-metal seals for some soft glasses and ceramics, and that its rate of thermal expansion is virtually constant to a temperature of about 1050°F (565°C). Its mean thermal expansion is 9.8 µm/m-°C over 25 to 450 °C in the Ulbrich datasheet. The nickel content is not agreed. Ulbrich and Hamilton Precision Metals print 50.5 %, while JLC Electromet and Elan Technology print 52 % (the Elan page writes "52% Nickel, Balance Iron"). The Ulbrich sheet gives the density as 8.30 g/cm3. The California Fine Wire datasheet gives another density, but its page could not be re-checked from the stored copy, so that figure is not recorded.
  uses:
    - where: Magnetic reed switches
      line: Ulbrich lists magnetic reed switches among the applications of Alloy 52 wire. The same list names glass-to-metal seals that need controlled linear expansion.
    - where: Glass-to-metal seals
      line: Ulbrich says the alloy was developed for glass-to-metal seals for some soft glasses and ceramics. Elan Technology calls No. 52 alloy "an ideal candidate for Elan 13" and gives no expansion value for that glass.
    - where: Spacecraft use
      line: No NASA, ESA or flight source for Alloy 52 was found. The uses above are terrestrial electronics and component applications.
  can_do:
    - label: Seal to soft glass
      line: Ulbrich describes the alloy as developed for glass-to-metal seals for some soft glasses and ceramics.
    - label: Hold a steady expansion
      line: Ulbrich says the rate of thermal expansion is virtually constant up to a temperature of about 1050°F (565°C).
    - label: Carry a magnetic function
      line: Hamilton Precision Metals lists a Curie temperature of 510°C approx and magnetic attraction as yes.
    - label: Come in many forms
      line: Ulbrich lists shaped, flat, square, round and fine wire, plated or bare.
  compare: Alloy 52 is chosen for matching expansion to glass, not for conductivity or strength. Its thermal conductivity is printed in the sources at widely different values (14.0 W/m·K in one datasheet and 140 W/m·K in another), so no ranking against copper or aluminium is made here. The table compares density, melting point and expansion with other profiles on the site only in the same units and conditions.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Melting point
      benchmark: melting_point
    - label: Thermal expansion
      benchmark: cte
  handling:
    - Specify the temper, since the sources give annealed typical values and cold rolling changes strength.
    - Do not expect heat treatment to harden the alloy; Ulbrich says it is non hardenable.
    - No safety data sheet for the alloy was found, so check the supplier's sheet before machining or dusting.
  good_for:
    - 'Glass-to-metal seals: Ulbrich says the alloy was developed for soft glass and ceramic seals.'
    - 'Magnetic reed switches: Ulbrich lists this as an application.'
  watch_out:
    - 'Conflicting figures: nickel is 50.5 nom in Ulbrich but 52 in JLC Electromet, and thermal conductivity differs by a factor of ten between sources.'
    - No corrosion, oxidation or ageing data were found. Ulbrich refers readers to NACE only.
    - No flight or space test result was found for this alloy.
  verdict: Alloy 52 is a glass-matching iron-nickel alloy with a documented expansion curve and a few terrestrial uses. Corrosion behaviour is unverified, and the sources disagree on nickel content and conductivity, so the figures need checking before design use.