spore: profile
id: manganin
spore_version: 0.2
family: resistance-and-thermocouple-alloys
name: Manganin
abbreviation: CuMn12Ni
role: precision resistance alloy for standards, shunts and gauges
category: metals
type: copper-alloys
summary: |
  Manganin is a copper-manganese-nickel alloy, nominally 12 % manganese and 2 % nickel with copper as the balance, sold by Isabellenhütte as MANGANIN (material code 2.1362). Its resistivity is 43 µΩ·cm at 20 °C and its resistance changes by only -10 to +10 ppm/K between 20 and 50 °C, which is why the maker calls it the standard material for precision, standard and shunt resistors. Edward Weston developed it in 1892 as a successor to constantan. From 1901 to 1990 the US legal ohm was kept by manganin resistance standards (NIST), and Micro-Measurements gives 0.27 % per kilobar for manganin foil pressure gauges used in shock-wave studies up to over 400 kilobars.
best_for: 'Precision resistors, resistance standards and current shunts whose resistance must stay nearly constant near room temperature: about ±10 ppm/K between 20 and 50 °C'
weakest_at: 'Heat and humidity: the supplier limits precision resistors to 60 °C and gives 140 °C as the maximum in air (Goodfellow prints 300 °C), and NIST shows that an unsealed winding drifts with atmospheric humidity.'
identity:
  formula: Cu-Mn-Ni alloy, nominally 12 % Mn and 2 % Ni with copper the balance (Isabellenhütte CuMn12Ni); Goodfellow lists Cu 86 / Mn 12 / Ni 2
  source: isa-datasheet
  where: 'Chemical Composition table, mass components: Cu Rem., Mn 12, Ni 2 (average values). Goodfellow composition line on its product page gives the same nominal ratio.'
  designations:
    - system: EN
      code: '2.1362'
      source: isa-datasheet
      where: Material Code field, 2.1362
    - system: Trade name
      code: Manganin
      source: isa-datasheet
      where: Brand Name field, MANGANIN, a trademark of Isabellenhütte Heusler
tags:
  environments: []
  applications:
    - electronics-and-chips
    - thermal-control
properties:
  - benchmark: density
    label: Density at 20 °C, MANGANIN
    value: 8.4
    unit: g/cm3
    scope: material
    conditions:
      grade: MANGANIN (CuMn12Ni), Isabellenhütte
      temperature: 20 °C
    method: Reference value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Physical Characteristics table, Density at 20 °C column
  - benchmark: density
    label: Density, Manganin wire
    value: 8.4
    unit: g/cm3
    scope: material
    conditions:
      form: wire (Goodfellow Manganin wire product page)
      temperature: not stated
    method: Value printed on a supplier product page
    status: ground
    source: goodfellow-wire
    where: Material Properties, Physical Properties, Density
  - benchmark: melting_point
    label: Melting point, MANGANIN
    value: 960
    unit: °C
    scope: material
    conditions:
      grade: MANGANIN (CuMn12Ni), Isabellenhütte
      pressure: not stated
    method: Reference value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Physical Characteristics table, Melting Point column
  - benchmark: melting_point
    label: Melting point, Manganin wire
    value: 960
    unit: °C
    scope: material
    conditions:
      form: wire (Goodfellow)
      pressure: not stated
    method: Value printed on a supplier product page
    status: ground
    source: goodfellow-wire
    where: Thermal Properties, Melting point
  - benchmark: electrical_resistivity
    label: Electrical resistivity at 20 °C, MANGANIN reference value
    value: 43
    unit: µΩ·cm
    scope: material
    conditions:
      temperature: 20 °C
      basis: reference value (first line of the resistance table; second line is CMF)
    method: Reference value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Electrical Resistance (Reference Values) table, 20 °C column, first line (µΩ x cm)
  - benchmark: electrical_resistivity
    label: Electrical resistivity at 100 °C, MANGANIN reference value
    value: 43
    unit: µΩ·cm
    scope: material
    conditions:
      temperature: 100 °C
      basis: reference value (first line of the resistance table)
    method: Reference value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Electrical Resistance (Reference Values) table, 100 °C column, first line
  - benchmark: electrical_resistivity
    label: Electrical resistivity, Manganin wire
    value: 43
    value_high: 48
    bound: range
    unit: µΩ·cm
    scope: material
    conditions:
      form: wire (Goodfellow)
      temperature: not stated
    method: Range printed on a supplier product page
    status: ground
    source: goodfellow-wire
    where: Electrical Properties, Electrical resistivity
  - benchmark: temperature_coefficient_of_resistance
    label: Temperature coefficient of electrical resistance, 20 to 50 °C
    value: -10
    value_high: 10
    bound: range
    unit: ppm/K
    scope: material
    conditions:
      temperature: 20 to 50 °C
      unit_in_source: 10-6/K
      basis: parabolic R/T curve; the sheet says the value can be adjusted to a degree on request
    method: Range printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Electrical Resistance (Reference Values) table, first column, temperature coefficient between 20 °C and 50 °C
  - benchmark: temperature_coefficient_of_resistance
    label: Temperature coefficient of electrical resistance, 20 to 105 °C
    value: 50
    unit: ppm/K
    scope: material
    conditions:
      temperature: 20 to 105 °C
      unit_in_source: ±50 ppm/K
      sign: printed as ±50, so the value is the magnitude of the spread
    method: Value printed in a manufacturer datasheet, in the special remarks text
    status: ground
    source: isa-datasheet
    where: Notes on Treatment, Special Remarks on the Temperature Coefficient, sentence on 20 to 105 °C
  - benchmark: specific_heat
    label: Specific heat at 20 °C, MANGANIN
    value: 0.41
    unit: J/(g·K)
    scope: material
    conditions:
      grade: MANGANIN (CuMn12Ni), Isabellenhütte
      temperature: 20 °C
    method: Reference value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Physical Characteristics table, Specific heat at 20 °C column
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 20 °C, MANGANIN
    value: 22
    unit: W/(m·K)
    scope: material
    conditions:
      grade: MANGANIN (CuMn12Ni), Isabellenhütte
      temperature: 20 °C
    method: Reference value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Physical Characteristics table, Thermal conductivity at 20 °C column
  - benchmark: thermal_conductivity
    label: Thermal conductivity, Manganin wire
    value: 22
    unit: W/(m·K)
    scope: material
    conditions:
      form: wire (Goodfellow)
      temperature: 23 °C
    method: Value printed on a supplier product page
    status: ground
    source: goodfellow-wire
    where: Thermal Properties, Thermal conductivity (printed as 22@23°C)
  - benchmark: cte
    label: Coefficient of thermal expansion, 20 to 100 °C, MANGANIN
    value: 18
    unit: ppm/K
    scope: material
    conditions:
      grade: MANGANIN (CuMn12Ni), Isabellenhütte
      temperature: 20 to 100 °C
    method: Reference value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Physical Characteristics table, average linear thermal expansion coefficient, 20 °C to 100 °C column
  - benchmark: cte
    label: Coefficient of thermal expansion, 20 to 400 °C, MANGANIN
    value: 19.5
    unit: ppm/K
    scope: material
    conditions:
      grade: MANGANIN (CuMn12Ni), Isabellenhütte
      temperature: 20 to 400 °C
    method: Reference value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Physical Characteristics table, average linear thermal expansion coefficient, 20 °C to 400 °C column
  - benchmark: cte
    label: Coefficient of thermal expansion, Manganin wire
    value: 14
    value_high: 19
    bound: range
    unit: ppm/K
    scope: material
    conditions:
      form: wire (Goodfellow)
      temperature: 20 to 100 °C
    method: Range printed on a supplier product page
    status: ground
    source: goodfellow-wire
    where: Thermal Properties, Coefficient of thermal expansion (printed as 14-19@20-100°C)
  - benchmark: thermoelectric_emf_vs_copper
    label: Thermoelectric emf against copper at 20 °C, MANGANIN
    value: -0.6
    unit: µV/K
    scope: material
    conditions:
      reference: emf against copper (Cu)
      temperature: 20 °C
    method: Reference value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Physical Characteristics table, Thermal EMF against copper at 20 °C column
  - benchmark: max_service_temp
    label: Maximum working temperature in air, MANGANIN
    value: 140
    unit: °C
    scope: material
    conditions:
      atmosphere: air
      basis: maximum working temperature in air, as stated by the maker
    method: Value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Features and Application Notes, maximum working temperature in air
  - benchmark: max_service_temp
    label: Temperature limit for precision resistors, MANGANIN
    value: 60
    unit: °C
    scope: material
    conditions:
      use: precision resistors with the highest requirements
      basis: the sheet says the temperature should not exceed 60 °C for precision resistors
    method: Value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Features and Application Notes, sentence beginning When used for precision resistors
  - benchmark: max_service_temp
    label: Maximum use temperature in air, Manganin wire
    value: 300
    unit: °C
    scope: material
    conditions:
      form: wire (Goodfellow)
      atmosphere: air
      note: conflicts with the 140 °C maximum working temperature in the Isabellenhütte sheet
    method: Value printed on a supplier product page
    status: ground
    source: goodfellow-wire
    where: Thermal Properties, Maximum use temperature in air
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, annealed wire 2 mm diameter, MANGANIN
    value: 390
    unit: MPa
    scope: material
    conditions:
      temper: annealed
      form: round wire, 2 mm diameter (footnote applies to this diameter)
      temperature: 20 °C
    method: Value printed in a manufacturer datasheet, footnote 4
    status: ground
    source: isa-datasheet
    where: Strength Properties at 20 °C in annealed condition table, Tensile strength, footnote 4
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, Manganin wire
    value: 300
    value_high: 600
    bound: range
    unit: MPa
    scope: material
    conditions:
      form: wire (Goodfellow)
      temper: not stated
    method: Range printed on a supplier product page
    status: ground
    source: goodfellow-wire
    where: Mechanical Properties, Tensile strength
  - benchmark: elongation
    label: Elongation, annealed wire over 1 mm diameter, MANGANIN
    value: 25
    bound: lower
    unit: '%'
    scope: material
    conditions:
      temper: annealed
      form: round wire over 1 mm diameter
      gauge_length: L0 = 100 mm
    method: Minimum value printed in a manufacturer datasheet
    status: ground
    source: isa-datasheet
    where: Strength Properties table, Elongation (L0 = 100 mm), column over 1 mm (printed as 25 or more)
  - benchmark: elongation
    label: Elongation at break, Manganin wire
    value: 50
    unit: '%'
    scope: material
    conditions:
      form: wire (Goodfellow)
      temper: not stated
    method: Value printed on a supplier product page
    status: ground
    source: goodfellow-wire
    where: Mechanical Properties, Elongation at break
  - benchmark: elastic_modulus
    label: Modulus of elasticity, Manganin wire
    value: 124
    value_high: 159
    bound: range
    unit: GPa
    scope: material
    conditions:
      form: wire (Goodfellow)
      temperature: not stated
    method: Range printed on a supplier product page
    status: ground
    source: goodfellow-wire
    where: Mechanical Properties, Modulus of elasticity
  - benchmark: pressure_sensitivity_of_resistance
    label: Nominal pressure sensitivity, manganin foil gauge
    value: 0.27
    unit: '% per kilobar'
    scope: material
    conditions:
      form: Micro-Measurements manganin foil gauge (not bulk alloy)
      basis: nominal value for hydrostatic and shock pressure use
    method: Nominal value printed in a manufacturer technical information sheet
    status: ground
    source: vishay-vpg
    where: Technical Information, first column, sentence Nominal pressure sensitivity of Micro-Measurements manganin foil gages is 0.27% per kilobar
corrosion:
  - environment: Air at room temperature (oxide film)
    headline: A thin oxide film forms on the alloy in air and must be removed before it is worked.
    effect: Isabellenhütte says the alloy can be soldered, but it develops a thin oxide film in air that must be removed before working. The sheet prints no oxidation rate or test data.
    rating: low
    conditions:
      basis: manufacturer statement, no rate printed
    source: isa-datasheet
    where: Notes on Treatment, first paragraph
  - environment: Humid air around an unsealed wound resistor
    headline: Unsealed manganin resistors changed resistance with atmospheric humidity; sealing them in a double-walled container fixed it.
    effect: NIST says the early Reichsanstalt-type standards were not hermetically sealed and so changed resistance with atmospheric humidity. Rosa at NBS sealed the element in mineral oil in 1907, and Thomas's later design used a hermetically sealed double-walled enclosure. NIST prints no drift rate.
    rating: moderate
    conditions:
      basis: NIST historical description of resistor groups; no drift rate printed
    source: nist-sp958
    where: Opening pages, paragraph on the 1901 to 1909 Reichsanstalt-type group, and the description of Thomas-type resistors
  - environment: High temperature in air
    headline: 'The supplier limits differ: 140 °C maximum in air and 60 °C for precision resistors (Isabellenhütte), 300 °C for wire (Goodfellow).'
    effect: Isabellenhütte gives 140 °C as the maximum working temperature in air and 60 °C for precision resistors. Goodfellow prints 300 °C as the maximum use temperature in air for its wire. Neither sheet prints an oxidation rate or a drift figure above its limit.
    rating: moderate
    conditions:
      basis: two supplier statements that disagree; no test data printed
    source: isa-datasheet
    where: Features and Application Notes, maximum working temperature in air and precision resistor sentence
risks:
  hazards:
    - text: Nickel is about 2 % of the alloy in the Isabellenhütte composition (3.7 % in the Wikipedia description). The nickel wire safety data sheet (NextSDS, CAS 7440-02-0, EC 231-111-4) lists H317 May cause an allergic skin reaction, H351 Suspected of causing cancer and H372 Causes damage to the lung, the kidneys and the liver through prolonged or repeated exposure, with signal word danger. That is the nickel metal classification; the manganin supplier SDS was not opened.
      ghs:
        - H317
        - H351
        - H372
      source: nextsds-ni
      where: Hazard Classifications and Hazard Statements of the nickel wire SDS page
    - text: PubChem's aggregated GHS entry for elemental manganese (CID 23930) has signal word Danger, with hazard codes H228 flammable solid (11.6 % of notifying companies), H319 causes serious eye irritation (14.8 %), and H411 and H412 for aquatic toxicity (about 11 % each). 46.1 % of 3101 company reports say the substance does not meet GHS criteria. These codes are for the metal, not the alloy.
      ghs:
        - H228
        - H319
        - H411
        - H412
      source: pubchem-mn
      where: Safety and Hazards, GHS Classification (Manganese, CID 23930)
  failure_risks:
    - mode: Precision resistor run above 60 °C
      trigger: Use of a MANGANIN precision resistor above 60 °C, the limit the Isabellenhütte sheet gives
      consequence: The sheet gives 60 °C as the limit for precision resistors but prints no drift or failure data above it, so the size of any error is not known from the sources read.
      severity: moderate
      source: isa-datasheet
      where: Features and Application Notes, sentence beginning When used for precision resistors
    - mode: Humidity drift in an unsealed winding
      trigger: A wound manganin resistor left open to humid air
      consequence: Resistance changes with atmospheric humidity, as NIST found for the early unsealed standards, so a calibration drifts with the weather unless the element is sealed.
      severity: moderate
      source: nist-sp958
      where: Opening pages, paragraph on the 1901 to 1909 Reichsanstalt-type group
    - mode: Unaged wound element
      trigger: A wound resistor put into use without ageing
      consequence: The sheet says resistors made of MANGANIN must be aged to remove mechanical stress. The sheet prints no drift figure for an unaged part.
      severity: low
      source: isa-datasheet
      where: Notes on Treatment, last sentence of the first column
  side_effects:
    - text: Copper is the balance of the alloy (Isabellenhütte Rem.), so copper prices and copper supply carry most of the cost. USGS reports 2025 world copper mine output of 23,000 thousand t.
      affects: Cost of the alloy
      source: usgs-cu-2026
      where: World Mine and Refinery Production table, mine production 2025e, world total
  handling:
    - text: The alloy can be soldered, but a thin oxide film forms in air and must be removed first. It is not suitable for dip-tinning, but it can be brazed and welded.
      source: isa-datasheet
      where: Notes on Treatment
    - text: Resistors made of MANGANIN must be aged to remove mechanical stress before use.
      source: isa-datasheet
      where: Notes on Treatment, last sentence of the first column
    - text: 'Read the nickel wire SDS before handling the alloy: its nickel metal classification (H317, H351, H372) applies to the nickel component, and the supplier''s own manganin SDS should be checked.'
      source: nextsds-ni
      where: Hazard Statements section
  mitigations:
    - text: 'NIST describes Thomas''s design: wire-wound resistors annealed at high temperature to release internal strains, and sealed in a hermetic double-walled container. Those standards were the US legal ohm from 1939 until the quantum Hall effect replaced them.'
      source: nist-sp958
      where: Description of the Thomas standard; the paragraph on the group used to maintain the U.S. Legal Ohm from 1939
uses:
  - application: electronics-and-chips
    device: Precision standard resistors (US legal ohm)
    example: From 1901 to 1990 the US legal ohm was maintained at 1 ohm by manganin resistance standards, and Thomas-type standards were the primary group from 1939 until the quantum Hall effect replaced them.
    source: nist-sp958
    where: Opening text, paragraph beginning From 1901 to 1990, the U.S. Legal Ohm
  - application: electronics-and-chips
    device: Precision, standard and shunt resistors
    example: Isabellenhütte calls MANGANIN the standard material for precision, standard and shunt resistors, because of its low temperature coefficient and low thermal emf against copper.
    source: isa-datasheet
    where: Features and Application Notes, first paragraph
  - application: electronics-and-chips
    device: Foil pressure gauges for shock-wave and high-pressure studies
    example: Micro-Measurements (Vishay) says manganin gauges are used extensively in shock-wave studies from 1 to over 400 kilobars. The foil gauge is bonded between two plates and has a nominal sensitivity of 0.27 % per kilobar.
    source: vishay-vpg
    where: Manganin Pressure Sensor sheet, first column, and Technical Information
  - application: thermal-control
    device: Cryogenic wiring from warm electronics to cold infrared detectors
    example: 'NASA CR-4477 (1993) says the conventional link uses 158 #40 AWG manganin wires in Kapton ribbon, which gives 33 % of the instrument heat load on the liquid cryogen in the SAFIRE design. It also says Kapton-coated manganin has already been used as an interconnect in space flight (its reference 7, a COBE performance review, not opened).'
    source: nasa-cr4477
    where: Introduction, item 1; text beside Table 1 on manganin in space flight
supply:
  - subject: Copper (the balance of the alloy), mine production 2025e
    producers:
      - country: Chile
        share_percent: 23
        year: 2025
      - country: Congo (Kinshasa)
        share_percent: 13.9
        year: 2025
      - country: Peru
        share_percent: 11.7
        year: 2025
      - country: China
        share_percent: 7.8
        year: 2025
      - country: Russia
        share_percent: 5.7
        year: 2025
    critical_lists:
      - list: U.S. Final 2025 List of Critical Minerals (copper added, per the USGS Mineral Commodity Summaries 2026)
        listed: true
    recycling: 'USGS: old scrap provided about 30 % of the U.S. copper supply in 2025, and brass and wire-rod mills took about 80 % of the copper recovered from scrap.'
    substitutes:
      - 'USGS: aluminum substitutes for copper in electrical equipment and power cable.'
    source: usgs-cu-2026
    where: World Mine and Refinery Production table, mine production 2025e (world total 23,000 thousand t). Shares calculated from the printed values 5,300, 3,200, 2,700, 1,800 and 1,300 over 23,000. Critical list paragraph, Recycling and Substitutes sections.
  - subject: Manganese (about 12 % of the alloy), mine production 2025e
    producers:
      - country: South Africa
        share_percent: 38
        year: 2025
      - country: Gabon
        share_percent: 25
        year: 2025
      - country: Ghana
        share_percent: 10
        year: 2025
      - country: Australia
        share_percent: 8
        year: 2025
      - country: India
        share_percent: 3.95
        year: 2025
    recycling: 'USGS: manganese was recycled only incidentally, as a constituent of ferrous and nonferrous scrap. US net import reliance was 100 % of apparent consumption.'
    substitutes:
      - 'USGS: manganese has no satisfactory substitute in its major applications.'
    source: usgs-mn-2026
    where: World Mine Production (manganese content) and Reserves table, 2025e column (world total 20,000 t, rounded). Shares calculated from the printed values 7,600, 5,000, 2,000, 1,600 and 790 over 20,000. Recycling, Import reliance and Substitutes paragraphs.
  - subject: Nickel (about 2 % of the alloy), mine production 2025e
    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
      - country: Canada
        share_percent: 3.6
        year: 2025
      - country: New Caledonia
        share_percent: 3.6
        year: 2025
    recycling: 'USGS: nickel recovered from scrap accounted for about 60 % of apparent consumption in 2025.'
    substitutes:
      - 'USGS: titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments; low-nickel and duplex stainless steels substitute for austenitic grades.'
    source: usgs-ni-2026
    where: World Mine Production and Reserves table, 2025e column (world total 3,900,000 t). Shares calculated from the printed values 2,600,000, 270,000, 200,000 and 140,000 (twice) over 3,900,000. Recycling and Substitutes paragraphs.
documents:
  - title: Isabellenhütte, MANGANIN data sheet, material code 2.1362, Issue 220606 (copy hosted by Jefferson Lab)
    type: datasheet
    url: https://hallaweb.jlab.org/tech/Detectors/public_html/manuals/data_sheets-manuals/G-I/I/ISABELLENHUETTE/MANGANIN-ISABELLENHUETTE-R.pdf
  - title: Goodfellow, Manganin wire (cu06-wr-000150), product page with material properties
    type: datasheet
    url: https://www.goodfellow.com/p/cu06-wr-000150/manganin-wire
  - title: Micro-Measurements (Vishay), Special Use Sensors, Manganin Pressure Sensor data sheet
    type: datasheet
    url: https://xdevs.com/doc/VPG/manganin.pdf
  - title: NIST Special Publication 958, Stability of Double-Walled Manganin Resistors (Thomas)
    type: report
    url: https://nvlpubs.nist.gov/nistpubs/sp958-lide/063-065.pdf
  - title: NASA Contractor Report 4477, A Comparison of Superconductor and Manganin Technology for Electronic Links Used in Space Mission Applications (1993)
    type: report
    url: https://ntrs.nasa.gov/api/citations/19930006398/downloads/19930006398.pdf
    year: 1993
  - title: NextSDS, Nickel wire safety data sheet, CAS 7440-02-0, hazard classification
    type: sds
    url: https://nextsds.com/sds/en/281331501257788/nickel-wire
  - title: PubChem, Manganese (CID 23930), Safety and Hazards, GHS Classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Manganese
  - title: 'USGS Mineral Commodity Summaries 2026: Copper'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Manganese'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-manganese.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
gaps:
  - 'No media entry: no licensed picture of a manganin resistor or gauge was checked in this run, so none is listed.'
  - 'Melting point: Wikipedia gives 1020 °C, but Isabellenhütte and Goodfellow both print 960 °C. Wikipedia is limited to composition and history under the brief, so 1020 °C is not entered.'
  - 'Maximum temperature in air conflicts: Isabellenhütte prints 140 °C (and 60 °C for precision resistors), Goodfellow prints 300 °C for its wire. Both are entered with their own source and the conflict is not resolved.'
  - 'Nickel content conflicts: Isabellenhütte and Goodfellow give 2 %, Wikipedia gives 3.7 % (its general description) and a Cu84/Mn12/Ni4 table from the CRC Handbook. Only the supplier figure is used for the property and supply rows; the Wikipedia figure appears in the recipe text.'
  - Kanthal Manganina 38 and 43 datasheets were found, but their tables did not come through as text, so no values are entered from them. They are not confirmed as the same grade, so they are not listed as designations.
  - 'Goodfellow temperature coefficient (printed as 0.00001 K⁻¹) is not entered: the range is not stated and the conversion to ppm/K was not confirmed in this run.'
  - 'Isabellenhütte modulus of elasticity (1.3 × 10^5 MPa, footnote 3) and pressure coefficient of electrical resistance (2.3 × 10^-7 cm²/N, footnote 3) are not entered: the printed exponent form does not match the value check. The Goodfellow modulus range is used instead.'
  - 'Yield strength and hardness: no yield value and no hardness value that matches a canonical name were read for manganin, so neither is entered.'
  - 'Non-canonical property names: temperature_coefficient_of_resistance, pressure_sensitivity_of_resistance and thermoelectric_emf_vs_copper are not in the canonical list and need adding to it.'
  - 'Designations: no UNS number was printed in any source read, so none is listed. The Isabellenhütte material code 2.1362 and the trade name MANGANIN are the only designations entered.'
  - Manganese critical-mineral status is not stated in the USGS Manganese summary read in this run, so no critical-list entry is given for manganese. Copper is listed (USGS, 2025 final list).
  - 'Occupational exposure limits for manganese (NIOSH, OSHA): the NIOSH pocket guide returned access denied, so no exposure limit is entered.'
  - Supplier SDS for manganin wire was not opened. The hazard entries use the nickel wire SDS and PubChem's classification for elemental manganese; neither is a classification of the alloy itself.
  - 'Space use: NASA CR-4477 says Kapton-coated manganin has flown as an interconnect (its reference 7, a COBE performance review). That reference was not opened, so the flight is cited, not verified, and no flight dates are given.'
  - 'Shock-wave use: the Micro-Measurements sheet is the only source read for the pressure gauge. The Fraunhofer calibration paper and G. I. Kanel''s shock-physics chapter were seen in search results only and not opened.'
  - Vacuum, outgassing, atomic-oxygen, radiation and cold-welding data for manganin were not found in any source read.
  - No corrosion rate, oxidation rate or humidity drift figure was printed in any source read; the corrosion rows give qualitative statements only.
  - Supply shares are calculated from printed USGS values, not printed as percentages in the sources.
  - The Isabellenhütte web product page returned 404 in the browser, so the datasheet used is the Issue 220606 copy hosted by Jefferson Lab.
  - Wikipedia was used only for composition, the 1892 date and the Weston history. Its infobox numbers and its manganin uses were not used as property or use values.
sources:
  isa-datasheet:
    title: Isabellenhütte, MANGANIN data sheet, material code 2.1362, Issue 220606 (copy hosted by Jefferson Lab)
    url: https://hallaweb.jlab.org/tech/Detectors/public_html/manuals/data_sheets-manuals/G-I/I/ISABELLENHUETTE/MANGANIN-ISABELLENHUETTE-R.pdf
    kind: datasheet
    license: Manufacturer datasheet (cited, not reproduced)
  goodfellow-wire:
    title: Goodfellow, Manganin wire (cu06-wr-000150), product page with material properties
    url: https://www.goodfellow.com/p/cu06-wr-000150/manganin-wire
    kind: datasheet
    license: Supplier product page (cited, not reproduced)
  vishay-vpg:
    title: Micro-Measurements (Vishay), Special Use Sensors, Manganin Pressure Sensor data sheet
    url: https://xdevs.com/doc/VPG/manganin.pdf
    kind: datasheet
    license: Manufacturer data sheet (cited, not reproduced)
  nist-sp958:
    title: NIST Special Publication 958, Stability of Double-Walled Manganin Resistors (Thomas)
    url: https://nvlpubs.nist.gov/nistpubs/sp958-lide/063-065.pdf
    kind: report
    license: US government publication (cited, not reproduced)
  nasa-cr4477:
    title: NASA Contractor Report 4477, A Comparison of Superconductor and Manganin Technology for Electronic Links Used in Space Mission Applications (1993)
    url: https://ntrs.nasa.gov/api/citations/19930006398/downloads/19930006398.pdf
    kind: report
    year: 1993
    license: public domain (NASA)
  nextsds-ni:
    title: NextSDS, Nickel wire safety data sheet, CAS 7440-02-0, hazard classification
    url: https://nextsds.com/sds/en/281331501257788/nickel-wire
    kind: datasheet
    license: SDS summary page (cited, not reproduced)
  pubchem-mn:
    title: PubChem, Manganese (CID 23930), Safety and Hazards, GHS Classification
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Manganese
    kind: database
    license: public domain (NIH PubChem)
  usgs-cu-2026:
    title: Mineral Commodity Summaries 2026, Copper
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mn-2026:
    title: Mineral Commodity Summaries 2026, Manganese
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-manganese.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-ni-2026:
    title: Mineral Commodity Summaries 2026, Nickel
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  wikipedia-manganin:
    title: Wikipedia, Manganin (composition, 1892 development and history only)
    url: https://en.wikipedia.org/wiki/Manganin
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 25
  unreachable: 2
  caveats: 4
  note: 'Values were read by an AI assistant on 2026-10-26 from the Isabellenhütte datasheet copy (Jefferson Lab), the Goodfellow product page, the Micro-Measurements sheet, NIST SP 958, NASA CR-4477 and USGS MCS 2026. Unreachable: the Isabellenhütte web product page (404) and the Kanthal Manganina pages (tables not extracted). Caveats: the 140 °C and 300 °C maximum temperatures conflict; the nickel share differs between suppliers and Wikipedia; the space flight is cited from a NASA report reference that was not opened; the hazard codes are for the nickel metal and the manganese element, not the alloy.'
story:
  risk_groups:
    - title: For people
      lead: The hazards come from the nickel and manganese in the alloy. The opened sources classify the metals, not the alloy, and the manganin supplier SDS was not read.
      level: 1
      verdict: Metal classifications
      points:
        - label: Nickel
          line: The nickel wire SDS lists H317 (allergic skin reaction), H351 (suspected of causing cancer) and H372 (organ damage on prolonged exposure). Nickel is about 2 % of the alloy in the supplier composition.
        - label: Manganese
          line: PubChem's entry for elemental manganese carries signal word Danger, with H228 (flammable solid), H319 (serious eye irritation) and H411 and H412 (aquatic toxicity).
    - title: If it fails
      lead: The sources give temperature limits and a humidity history, but no failure data beyond them.
      points:
        - label: Above 60 °C
          line: Isabellenhütte says precision resistors should not exceed 60 °C. Above it, no drift data are printed.
        - label: Humid air
          line: NIST found that unsealed early standards changed resistance with atmospheric humidity. Sealing fixed it.
    - title: Handling and storage
      points:
        - label: Age the wound part
          line: Resistors made of MANGANIN must be aged to remove mechanical stress before use.
        - label: Check the SDS
          line: Read the supplier SDS before handling. The nickel component carries H317, H351 and H372 in its own SDS.
  why: Manganin is a copper-manganese-nickel alloy sold for resistance that barely changes near room temperature. Isabellenhütte gives a temperature coefficient of -10 to +10 ppm/K between 20 and 50 °C and a resistivity of 43 µΩ·cm, and calls it the standard material for precision, standard and shunt resistors. It has a thermal emf of -0.6 µV/K against copper, so it adds little spurious voltage in DC circuits. NIST records that manganin resistors kept the US legal ohm from 1901 to 1990.
  uses:
    - where: Resistance standards
      line: NIST says manganin resistors maintained the US legal ohm from 1901 to 1990, and Thomas-type standards were the primary group from 1939.
    - where: Shunts and precision resistors
      line: Isabellenhütte calls MANGANIN the standard material for precision, standard and shunt resistors.
    - where: Shock-wave gauges
      line: Micro-Measurements says manganin foil gauges are used in shock-wave studies from 1 to over 400 kilobars, with 0.27 % per kilobar sensitivity.
    - where: Cryogenic wiring
      line: A 1993 NASA report says manganin wires in Kapton ribbon were the conventional cryogenic link to infrared detectors, and that a Kapton-coated manganin interconnect has already flown (cited, not verified).
  can_do:
    - label: Stay constant
      value: '-10 to +10 ppm/K'
      benchmark: temperature_coefficient_of_resistance
      line: Isabellenhütte gives -10 to +10 ppm/K between 20 and 50 °C. Its sheet says the figure widens to ±50 ppm/K between 20 and 105 °C.
    - label: Carry current in a standard
      value: 43 µΩ·cm
      benchmark: electrical_resistivity
      line: Resistivity is 43 µΩ·cm at both 20 °C and 100 °C in the Isabellenhütte reference table.
    - label: Stay in the heat
      value: 60 °C
      benchmark: max_service_temp
      line: Isabellenhütte limits precision resistors to 60 °C and gives 140 °C as the maximum working temperature in air. Goodfellow gives 300 °C for its wire.
    - label: Weight
      value: 8.4 g/cm3
      benchmark: density
      line: Density is 8.4 g/cm3 in both the Isabellenhütte sheet and the Goodfellow wire page.
    - label: Strength
      value: 390 MPa
      benchmark: ultimate_tensile_strength
      line: Isabellenhütte gives 390 MPa tensile strength for annealed 2 mm wire. Goodfellow gives 300 to 600 MPa for wire.
  compare: Two suppliers give the same density of 8.4 g/cm3 and the same melting point of 960 °C, but disagree on the maximum temperature in air (140 °C in the Isabellenhütte sheet, 300 °C at Goodfellow). Their thermal conductivities (22 W/(m·K) at 20 °C and at 23 °C) agree. The table rows are examples from these two datasheets, not a ranking.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Temperature coefficient
      benchmark: temperature_coefficient_of_resistance
    - label: Maximum temperature
      benchmark: max_service_temp
  handling:
    - Age wound resistors to remove mechanical stress before use (Isabellenhütte).
    - Remove the oxide film before soldering, and do not dip-tin the alloy (Isabellenhütte).
    - Keep precision resistors at or below 60 °C (Isabellenhütte).
    - Read the supplier SDS before handling, since the nickel component carries H317, H351 and H372.
  good_for:
    - Precision and standard resistors with a temperature coefficient of -10 to +10 ppm/K between 20 and 50 °C (Isabellenhütte).
    - Current shunts, with a thermal emf of -0.6 µV/K against copper (Isabellenhütte).
    - Foil pressure gauges for shock-wave studies, at 0.27 % per kilobar (Micro-Measurements).
  watch_out:
    - 'Heat: precision resistors are limited to 60 °C, and the supplier maximum in air differs between 140 °C and 300 °C.'
    - 'Humidity: unsealed windings drift with atmospheric humidity (NIST).'
    - 'Nickel: the nickel component is classified H317, H351 and H372 in its own SDS.'
    - 'Space: the 1993 NASA report cites a flown Kapton-coated manganin interconnect, but that reference was not opened.'
  verdict: Manganin is a copper-manganese-nickel resistance alloy whose resistance barely changes near room temperature, which is why standards laboratories and shunt makers have used it for over a century. The datasheets limit precision resistors to 60 °C and give no drift data above that. Its nickel and manganese carry hazard classifications, and its space record rests on a 1993 NASA report that cites a flight without a date.