Monel 404 Alloy 404 (UNS N04404)

spore: profile
id: monel-404
spore_version: 0.2
family: nickel-alloys
name: Monel 404
abbreviation: Alloy 404 (UNS N04404)
role: low-permeability nickel-copper alloy for ceramic-to-metal seals
category: metals
type: nickel-superalloys
summary: |
  Monel 404 (UNS N04404, ASTM F96) is a nickel-copper alloy with nickel plus cobalt at 52.0 to 57.0 percent and copper as the balance, per the typical chemistry on the Ulbrich data sheet. Ulbrich prints a typical density of 8.91 g/cm3 and a melting point of 1300 °C. Wikipedia says its composition is adjusted for a very low Curie temperature and low permeability, which suits electronic seals.
best_for: Ceramic-to-metal seals and transistor capsules in electronic devices, and marine fixtures, where low magnetic permeability and corrosion resistance both matter
weakest_at: Corrosion data are qualitative only (no corrosion rate in any source read), and Wikipedia says the alloy cannot be hot worked
identity:
  formula: 'Nickel-copper alloy: nickel plus cobalt 52.0 to 57.0 percent, copper balance, iron 0.50 max, manganese 0.10 max, silicon 0.10 max, cobalt 1.00 max, carbon 0.15 max, sulfur 0.024 max, aluminum 0.05 max (wt%, Ulbrich Chemistry Typical)'
  source: ulbrich-404
  where: Chemistry Typical table (typical values only, per the sheet's disclaimer)
  designations:
    - system: UNS
      code: N04404
      source: ulbrich-404
      where: Title line, UNS N04404
    - system: ASTM
      code: F96
      source: wiki-monel
      where: Monel 404 section, covered by standards UNS N04404 and ASTM F96
    - system: Trade name
      code: Monel 404
      source: wiki-monel
      where: Alloys section, Monel 404 heading
    - system: Trade name
      code: Nickel 404
      source: ulbrich-404
      where: Description, Nickel 404 or Monel 404
tags:
  environments: []
  stresses: []
  applications:
    - electronics-and-chips
    - thermal-control
    - structures
properties:
  - benchmark: density
    value: 8.91
    unit: g/cm3
    scope: material
    conditions:
      basis: typical value; the sheet prints no temperature or condition
    method: Physical Properties section, printed as Density, 0.322 lbs/in3, 8.91 g/cm3
    status: ground
    source: ulbrich-404
    where: Physical Properties, Density row
  - benchmark: density
    label: Density on a supplier product page
    value: 8.85
    unit: g/cm3
    scope: material
    conditions:
      basis: Physical Properties table on the Kaixin Alloy product page; no temperature printed
    method: Monel 404 Physical Properties table, printed as 8.85 g/cm3 (the same page prints 8.91 g/cm3 in its product physical properties section)
    status: ground
    note: A supplier figure that differs from the Ulbrich sheet's 8.91 g/cm3. Both are recorded; the supplier page does not settle which is right.
    source: kx-alloy
    where: Monel 404 Physical Properties table
  - benchmark: melting_point
    value: 1300
    unit: °C
    scope: material
    conditions:
      basis: single melting point printed; no range
    method: Melting Point line, printed as 2370°F (1300°C)
    status: ground
    source: ulbrich-404
    where: Melting Point line
  - benchmark: melting_point
    label: Melting range on a supplier product page
    value: 1350
    value_high: 1390
    bound: range
    unit: °C
    scope: material
    conditions:
      basis: melting range printed in the supplier's Mechanical Properties (Typical) table
    method: Monel 404 Mechanical Properties (Typical) table, Melting Range row, printed as 1350–1390°C
    status: ground
    note: Differs from the single point of 1300 °C on the Ulbrich sheet. Both are recorded.
    source: kx-alloy
    where: Monel 404 Mechanical Properties (Typical) table, Melting Range row
  - benchmark: electrical_resistivity
    value: 0.498
    unit: microhm-m
    scope: material
    conditions:
      temperature: 70°F (21°C)
    method: Electrical Resistivity row at 70°F (21°C), microhm-m column, printed as 0.498 (the ohm-cir mil/ft column prints 294 in the same row)
    status: ground
    source: ulbrich-404
    where: Electrical Resistivity, row At 70°F (21°C)
  - benchmark: specific_heat
    value: 0.414
    unit: J/g-°C
    scope: material
    conditions:
      temperature: 70°F (21°C)
    method: Specific Heat row at 70°F (21°C), J/g-°C column, printed as 0.414 (the Btu/lb-°F column prints 0.0989 in the same row)
    status: ground
    source: ulbrich-404
    where: Specific Heat, row At 70°F (21°C)
  - benchmark: thermal_conductivity
    value: 21
    unit: W/m-°C
    scope: material
    conditions:
      temperature: 70°F (21°C)
    method: Thermal Conductivity row at 70°F (21°C), W/m-°C column, printed as 21 (the BTU column prints 133 in the same row)
    status: ground
    source: ulbrich-404
    where: Thermal Conductivity, row At 70°F (21°C)
  - benchmark: cte
    value: 13.3
    unit: µm/m°C
    scope: material
    conditions:
      temperature_range: 70 to 200°F (21 to 93°C)
      basis: mean coefficient of thermal expansion, as printed
    method: Mean Coefficient of Thermal Expansion table, first row, µm/m°C column
    status: ground
    source: ulbrich-404
    where: Mean Coefficient of Thermal Expansion table, row 70-200°F (21-93°C)
  - benchmark: cte
    value: 15.3
    unit: µm/m°C
    scope: material
    conditions:
      temperature_range: 70 to 572°F (21 to 300°C)
      basis: mean coefficient of thermal expansion, as printed
    method: Mean Coefficient of Thermal Expansion table, second row, µm/m°C column
    status: ground
    source: ulbrich-404
    where: Mean Coefficient of Thermal Expansion table, row 70-572°F (21-300°C)
  - benchmark: cte
    value: 16.6
    unit: µm/m°C
    scope: material
    conditions:
      temperature_range: 70 to 1000°F (21 to 539°C)
      basis: mean coefficient of thermal expansion, as printed
    method: Mean Coefficient of Thermal Expansion table, third row, µm/m°C column
    status: ground
    source: ulbrich-404
    where: Mean Coefficient of Thermal Expansion table, row 70-1000°F (21-539°C)
  - benchmark: cte
    value: 17.6
    unit: µm/m°C
    scope: material
    conditions:
      temperature_range: 70 to 1500°F (21 to 816°C)
      basis: mean coefficient of thermal expansion, as printed
    method: Mean Coefficient of Thermal Expansion table, fourth row, µm/m°C column
    status: ground
    source: ulbrich-404
    where: Mean Coefficient of Thermal Expansion table, row 70-1500°F (21-816°C)
  - benchmark: ultimate_tensile_strength
    value: 70
    bound: lower
    unit: ksi
    scope: material
    conditions:
      condition: annealed
      temperature: room temperature
      product: not split by product form on the sheet
    method: Mechanical Properties at Room Temperature, Properties Annealed, printed as 70 KSI min
    status: ground
    note: Minimum value printed for annealed material. The sheet's MPa figure for the same minimum is not recorded separately.
    source: ulbrich-404
    where: Mechanical Properties at Room Temperature, Properties Annealed, Ultimate Tensile Strength row
  - benchmark: yield_strength
    value: 25
    bound: lower
    unit: ksi
    scope: material
    conditions:
      condition: annealed
      temperature: room temperature, 0.2 percent offset
      product: not split by product form on the sheet
    method: Mechanical Properties at Room Temperature, Properties Annealed, printed as 25 KSI min
    status: ground
    source: ulbrich-404
    where: Mechanical Properties at Room Temperature, Properties Annealed, Yield Strength (0.2% offset) row
  - benchmark: elongation
    value: 35
    bound: lower
    unit: '%'
    scope: material
    conditions:
      condition: annealed
      temperature: room temperature
      product: not split by product form on the sheet
    method: Mechanical Properties at Room Temperature, Properties Annealed, printed as 35% min
    status: ground
    source: ulbrich-404
    where: Mechanical Properties at Room Temperature, Properties Annealed, Elongation row
corrosion:
  - environment: General corrosive environments (manufacturer statement)
    headline: Ulbrich describes excellent resistance to many corrosive environments, with no numeric rate printed.
    effect: Ulbrich says the alloy has good strength, toughness and excellent resistance to many corrosive environments. No corrosion rate, medium or exposure time is printed.
    rating: low
    conditions:
      basis: qualitative statement; no medium, temperature or exposure time printed
    source: ulbrich-404
    where: Description
  - environment: Named media and NACE recommendations
    headline: Ulbrich points to NACE for corrosion recommendations and prints no test data.
    effect: The Ulbrich sheet gives no corrosion rate, pitting or stress-corrosion result. It refers readers to NACE (National Association of Corrosion Engineers) for recommendations.
    rating: unknown
    conditions:
      basis: referral only, no test data
    source: ulbrich-404
    where: Additional Properties, Corrosion Resistance
  - environment: Seawater and marine fixtures
    headline: No Monel 404 seawater test result was found; marine use is listed by Ulbrich.
    effect: Ulbrich lists marine fixtures as an application but prints no seawater corrosion rate. Wikipedia says the Monel group resists rapidly flowing seawater, but that describes the group, not this grade, so it is not counted here.
    rating: unknown
    conditions:
      basis: application listed; no seawater test data for this grade
    source: ulbrich-404
    where: Applications list
  - environment: Galvanic contact with steel in salt water
    headline: Wikipedia says Monel alloys must be insulated from steel in salt water (a group statement).
    effect: Wikipedia says Monel must be carefully insulated from other metals such as steel in marine use. The statement covers the Monel group, and no Monel 404 rate was read.
    rating: moderate
    conditions:
      basis: qualitative group-level statement, no rate printed
    source: wiki-monel
    where: Marine applications section
risks:
  hazards:
    - text: PubChem aggregated GHS for nickel metal (CID 935) lists H317 in 99.9% of reports that give a code, H351 in 72.9%, H372 in 99.7% and H412 in 47.2%. Nickel is about 52.0 to 57.0 percent of this alloy (Ulbrich), so the record describes the metal, not the alloy.
      ghs:
        - H317
        - H351
        - H372
        - H412
      source: pubchem-nickel
      where: Safety and Hazards, GHS Classification, aggregated per 4778 company reports
    - text: PubChem aggregated GHS for copper metal (CID 23978) lists H400 in 43.1% of reports that give a code, H410 in 18.8%, H411 in 22.5% and H302 in 21.7%. Copper is the balance of this alloy (Ulbrich), so the record describes the metal, not the alloy.
      ghs:
        - H400
        - H410
        - H411
        - H302
      source: pubchem-copper
      where: Safety and Hazards, GHS Classification, aggregated per 3463 company reports
    - text: No safety data sheet for solid Monel 404 was read, and the Ulbrich sheet carries no hazard statement.
      ghs: []
      source: ulbrich-404
      where: Whole sheet; limitation of liability and disclaimer
  failure_risks:
    - mode: Hot working of the alloy
      trigger: Attempting to hot work or forge the material
      consequence: Wikipedia says Monel 404 cannot be hot worked, although it can be welded and cold worked. The Ulbrich sheet is silent on hot working.
      severity: moderate
      source: wiki-monel
      where: Monel 404 section
    - mode: Galvanic attack on steel in salt water
      trigger: Direct contact with steel in salt water
      consequence: Wikipedia says Monel must be carefully insulated from steel in salt water. The statement covers the Monel group, and no Monel 404 test was read.
      severity: moderate
      source: wiki-monel
      where: Marine applications section
  side_effects: []
  handling:
    - text: Weld with common welding techniques; for best results follow SSINA's Welding of Stainless Steels and Other Joining Methods (Ulbrich).
      source: ulbrich-404
      where: Welding
    - text: Cold work with standard tooling and soft die materials for a better finish (Wikipedia).
      source: wiki-monel
      where: Monel 404 section
    - text: Ulbrich says Monel 404 is non-hardenable by heat treatment, and that tempered product can be cold rolled to customer requirements (contact Ulbrich).
      source: ulbrich-404
      where: 'Heat Treatment; Properties: Tempered'
    - text: The Ulbrich disclaimer says all data are typical values only and not recommended for specification, design or engineering.
      source: ulbrich-404
      where: Limitation of Liability and Disclaimer of Warranty
  mitigations:
    - text: Confirm temper and product form on a mill certificate before design, because the Ulbrich values are typical values or minimums.
      source: ulbrich-404
      where: Mechanical Properties; Disclaimer
    - text: Insulate Monel from steel in salt water to avoid galvanic attack (Wikipedia, group statement).
      source: wiki-monel
      where: Marine applications section
    - text: Avoid hot working; shape the alloy cold, as the Wikipedia note on Monel 404 describes.
      source: wiki-monel
      where: Monel 404 section
uses:
  - application: electronics-and-chips
    device: Transistor capsules and ceramic-to-metal seals
    example: Wikipedia says Monel 404 is used in capsules for transistors and in ceramic-to-metal seals. Ulbrich lists electronic devices where ceramic-to-metal sealing is required.
    source: wiki-monel
    where: Monel 404 section
  - application: thermal-control
    device: Boiler feed water heaters and other heat exchanger components
    example: Ulbrich lists boiler feed water heaters and other heat exchanger components among the applications.
    source: ulbrich-404
    where: Applications list
  - application: structures
    device: Marine fixtures
    example: Ulbrich lists marine fixtures among the applications. No seawater corrosion test result was found for this grade.
    source: ulbrich-404
    where: Applications list
supply:
  - subject: Nickel
    abundance: Globally, nickel resources have been estimated to contain more than 350 million tons of nickel (USGS).
    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
    critical_lists: []
    recycling: In 2025, nickel recovered from scrap accounted for approximately 60% of apparent consumption (USGS).
    substitutes:
      - Titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments (USGS).
    source: usgs-mcs2026-nickel
    where: World Mine Production and Reserves table, 2025e column (world total 3,900,000 t); shares calculated by Space Mushroom from the printed tonnages; Recycling; Substitutes; World Resources
  - subject: Copper
    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
    critical_lists:
      - list: U.S. Final 2025 List of Critical Minerals (90 FR 50494; copper added)
        listed: true
    recycling: Old scrap provided an estimated 160,000 tons of copper in 2025, and new scrap an estimated 760,000 tons; copper recovered from scrap contributed about 30% of the U.S. copper supply (USGS).
    substitutes:
      - Titanium and steel are used in heat exchangers (USGS).
    source: usgs-mcs2026-copper
    where: World Mine and Refinery Production table, mine production 2025e (world total 23,000 thousand t); shares calculated by Space Mushroom; Events, Trends, and Issues (critical minerals); Recycling; Substitutes
media: []
documents:
  - title: Monel 404 (Nickel 404), UNS N04404 data sheet, Ulbrich Stainless Steels and Special Metals
    type: datasheet
    url: https://d2ykdomew87jzd.cloudfront.net/data-sheets/Monel-404-Nickel-404-UNS-N04404.pdf
    year: 2015
  - title: Monel, Wikipedia English article (Monel 404 section)
    type: database
    url: https://en.wikipedia.org/wiki/Monel
  - title: Monel 404 product page, Kaixin Alloy Materials Co., Ltd.
    type: datasheet
    url: https://en.kx-alloy.com/products_page.html?id=88
  - title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Copper'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
  - title: PubChem nickel (CID 935), GHS classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/935/JSON?heading=GHS+Classification
  - title: PubChem copper (CID 23978), GHS classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23978/JSON?heading=GHS+Classification
  - title: MONEL Alloy 404 (UNS N04404), AZoM product page
    type: database
    url: https://www.azom.com/metals/nickel-alloys_monel%C2%AE-alloy-404-(uns-n04404)
gaps:
  - No corrosion rate, critical pitting temperature, ASTM G48 result or stress-corrosion threshold for Monel 404 was found in any source read. The corrosion entries are qualitative or rated unknown.
  - Ulbrich prints the modulus of elasticity with an exponent (24.5 x 10³ ksi and 169 x 10³ MPa). Values written with exponents are left out, so no modulus is recorded.
  - No Curie temperature number was found. Wikipedia says the composition gives a very low Curie temperature but prints no value.
  - No maximum or minimum service temperature is printed in any source read.
  - No electrical conductivity (% IACS), fatigue, impact or hardness value for Monel 404 was found in the sources read.
  - No EN, DIN, JIS or W.Nr. number for Monel 404 is printed in any source read, so none is listed. The ASTM F96 standard text is not open and was not read.
  - The ASM Alloy Digest for Monel alloy 404 is behind a paywall and was not read.
  - The Ulbrich sheet prints a magnetic permeability maximum (1.0017 at H = 200 Oersteds, annealed) with no unit printed, so the value is left out rather than given a unit.
  - The Ulbrich chemistry and physical values are typical values only, and its mechanical values are minimums for annealed material. The sheet does not split mechanical values by product form.
  - A Kaixin Alloy supplier page prints a nickel range, a density and a melting range that differ from the Ulbrich sheet. Its density and melting range are recorded as supplier values; its composition is not used. Its thermal, electrical and expansion figures match the Monel 400 values in this site's monel-400 profile, so they are not recorded as Monel 404 values.
  - The USGS nickel summary mentions the critical-minerals list only in passing and prints no list status for nickel, so no critical_lists entry is recorded for nickel.
  - Wikipedia's seawater, galvanic and insulation statements describe the Monel group in general, not tests on Monel 404.
  - No alloy safety data sheet was read. The hazard entries are PubChem records for nickel and copper, which describe the metals, not the alloy.
  - No space, vacuum, outgassing or radiation data were found for Monel 404.
sources:
  ulbrich-404:
    title: Monel 404 (Nickel 404), UNS N04404 data sheet, Ulbrich Stainless Steels and Special Metals
    id: Copyright January 2014, Revision 6.1.2015
    url: https://d2ykdomew87jzd.cloudfront.net/data-sheets/Monel-404-Nickel-404-UNS-N04404.pdf
    year: 2015
    kind: datasheet
    license: Supplier terms (cited, not reproduced)
  wiki-monel:
    title: Monel
    id: Wikipedia, English article, Monel 404 section (read in this run)
    url: https://en.wikipedia.org/wiki/Monel
    kind: web
    license: CC BY-SA 4.0
  kx-alloy:
    title: Monel 404 product page, Kaixin Alloy Materials Co., Ltd.
    id: Undated supplier page, read in this run
    url: https://en.kx-alloy.com/products_page.html?id=88
    kind: web
    license: Supplier page (cited, not reproduced)
  usgs-mcs2026-nickel:
    title: 'Mineral Commodity Summaries 2026: Nickel'
    id: USGS, Mineral Commodity Summaries 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: US Government work (public domain)
  usgs-mcs2026-copper:
    title: 'Mineral Commodity Summaries 2026: Copper'
    id: USGS, Mineral Commodity Summaries 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
    kind: report
    license: US Government work (public domain)
  pubchem-nickel:
    title: Nickel, PubChem CID 935, GHS classification (aggregated ECHA C&L notifications)
    id: PubChem CID 935
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/935/JSON?heading=GHS+Classification
    kind: database
    license: PubChem (NIH, public domain)
  pubchem-copper:
    title: Copper, PubChem CID 23978, GHS classification (aggregated ECHA C&L notifications)
    id: PubChem CID 23978
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23978/JSON?heading=GHS+Classification
    kind: database
    license: PubChem (NIH, public domain)
  azom-404:
    title: MONEL Alloy 404 (UNS N04404), AZoM product page
    id: AZoM metals database page, read in this run (heading and product forms only)
    url: https://www.azom.com/metals/nickel-alloys_monel%C2%AE-alloy-404-(uns-n04404)
    kind: web
    license: Supplier listing page (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 14
  unreachable: 0
  caveats: 2
  note: Written by an AI assistant on 2026-11-01 from the Ulbrich Monel 404 data sheet, the Wikipedia Monel article, a Kaixin Alloy supplier page, USGS MCS 2026 nickel and copper, and PubChem GHS records for nickel and copper. Every number was read from a page fetched in this run. Two density and melting-range values come from a supplier page and differ from the Ulbrich sheet; both are recorded.
story:
  recipe:
    line: 'Monel 404 is a nickel-copper alloy. Ulbrich prints its typical chemistry: nickel plus cobalt 52.0 to 57.0 percent, with copper as the balance and small limits on iron, manganese, silicon, carbon, sulfur and aluminum. Wikipedia says the composition is adjusted for a very low Curie temperature, low permeability and good brazing. Ulbrich prints no melting or manufacturing route.'
    parts:
      - name: Nickel plus cobalt
        symbol: Ni
        share_percent: 52
        share_high: 57
        share_note: 52.0 to 57.0, typical, nickel plus cobalt
        role: Matrix of the nickel-copper alloy. Cobalt is counted inside this combined limit on the Ulbrich sheet.
        source: ulbrich-404
        where: Chemistry Typical, Nickel + Cobalt row
      - name: Copper
        symbol: Cu
        share_note: balance
        role: The remainder of the alloy. Wikipedia calls the Monel group a solid-solution binary alloy of nickel and copper.
        source: ulbrich-404
        where: Chemistry Typical, Copper row
      - name: Iron
        symbol: Fe
        share_percent: 0.5
        share_note: 0.50 max
        role: Residual element, limited on the sheet.
        source: ulbrich-404
        where: Chemistry Typical, Iron row
      - name: Manganese
        symbol: Mn
        share_percent: 0.1
        share_note: 0.10 max
        role: Residual element, limited on the sheet.
        source: ulbrich-404
        where: Chemistry Typical, Manganese row
      - name: Silicon
        symbol: Si
        share_percent: 0.1
        share_note: 0.10 max
        role: Residual element, limited on the sheet.
        source: ulbrich-404
        where: Chemistry Typical, Silicon row
      - name: Carbon
        symbol: C
        share_percent: 0.15
        share_note: 0.15 max
        role: Residual element, limited on the sheet.
        source: ulbrich-404
        where: Chemistry Typical, Carbon row
      - name: Sulfur
        symbol: S
        share_percent: 0.024
        share_note: 0.024 max
        role: Residual element, limited on the sheet. Sulfur limits are low for this grade.
        source: ulbrich-404
        where: Chemistry Typical, Sulfur row
      - name: Aluminum
        symbol: Al
        share_percent: 0.05
        share_note: 0.05 max
        role: Residual element, limited on the sheet.
        source: ulbrich-404
        where: Chemistry Typical, Aluminum row
  risk_groups:
    - title: For people
      level: 2
      verdict: Metal flagged by nickel and copper records; no alloy SDS
      lead: No safety data sheet for solid Monel 404 was read. The flags come from PubChem records for nickel (about 52.0 to 57.0 percent of the alloy) and copper (the balance).
      points:
        - label: Nickel record
          line: PubChem aggregated GHS for nickel lists an allergic skin reaction (H317, 99.9%), suspected cancer (H351, 72.9%) and organ damage from prolonged exposure (H372, 99.7%).
        - label: Copper record
          line: PubChem aggregated GHS for copper lists very toxic to aquatic life (H400, 43.1%) and very toxic with long-lasting effects (H410, 18.8%).
    - title: If a part sees the wrong conditions
      lead: These results come from the datasheet and the Wikipedia article, not from field incidents.
      points:
        - label: Hot working
          line: Wikipedia says Monel 404 cannot be hot worked, so the part should be shaped cold.
        - label: Galvanic contact
          line: Wikipedia says Monel must be insulated from steel in salt water. That statement covers the Monel group.
        - label: Weak seawater data
          line: No corrosion rate or seawater test result for Monel 404 was found in the sources read.
    - title: Handling and heat treatment
      points:
        - label: Heat treatment
          line: Ulbrich says Monel 404 is non-hardenable by heat treatment.
        - label: Welding
          line: Ulbrich points to SSINA's welding guidance, and Wikipedia says common welding techniques apply.
        - label: Cold work
          line: Cold working uses standard tooling and soft die materials for a better finish (Wikipedia).
  why: Monel 404 (UNS N04404) is a nickel-copper alloy used in electronics. Ulbrich lists electronic devices where ceramic-to-metal sealing is required, and Wikipedia says the alloy is used in capsules for transistors. The composition is set for low magnetic permeability and good brazing, and the Ulbrich sheet adds good strength, toughness and corrosion resistance.
  uses:
    - where: Transistor capsules and ceramic-to-metal seals
      line: Wikipedia says Monel 404 is used primarily in specialized electrical and electronic applications, including capsules for transistors and ceramic-to-metal seals. Ulbrich lists electronic devices where ceramic-to-metal sealing is required.
    - where: Heat exchangers and boiler feed water heaters
      line: Ulbrich lists boiler feed water heaters and other heat exchanger components among its applications.
    - where: Marine fixtures
      line: Ulbrich lists marine fixtures among its applications. No seawater corrosion test result for this grade was found.
  can_do:
    - label: Low permeability
      line: Ulbrich describes low magnetic permeability as a property of the alloy, and Wikipedia says the composition is adjusted to give it. The Ulbrich figure has no printed unit, so it is left out (see gaps).
    - label: Density
      benchmark: density
      line: The Ulbrich sheet prints a typical density of 8.91 g/cm3. A supplier page prints 8.85 g/cm3, so the two values are recorded side by side.
    - label: Strength annealed
      benchmark: ultimate_tensile_strength
      value: 70 ksi min
      line: Annealed material has a minimum tensile strength of 70 ksi, a minimum 0.2 percent yield strength of 25 ksi and a minimum elongation of 35 percent (Ulbrich).
    - label: Thermal expansion
      benchmark: cte
      line: The mean coefficient of thermal expansion is 13.3 µm/m°C from 21 to 93 °C (Ulbrich), rising to 17.6 µm/m°C at 21 to 816 °C.
    - label: Melting point
      benchmark: melting_point
      line: The Ulbrich sheet prints a melting point of 1300 °C. A supplier page prints a melting range of 1350 to 1390 °C.
  compare: Monel 404 is one of the Monel grades, and Wikipedia says its composition is adjusted for a very low Curie temperature, low permeability and good brazing. Those are the properties to compare with other grades. Its typical density of 8.91 g/cm3 and melting point of 1300 °C (Ulbrich) are the figures to set beside the same benchmarks on other nickel alloys in this collection. No Monel 404 corrosion rate was found, so corrosion cannot be ranked from these sources.
  compare_rows:
    - label: Density
      benchmark: density
      scope: material
    - label: Melting point
      benchmark: melting_point
      scope: material
    - label: Electrical resistivity
      benchmark: electrical_resistivity
      scope: material
  handling:
    - Weld with common welding techniques, and follow SSINA's welding guidance for best results (Ulbrich, Wikipedia).
    - Cold work with standard tooling and soft die materials. Do not hot work the alloy (Wikipedia).
    - Monel 404 is non-hardenable by heat treatment (Ulbrich). Tempered product is available by cold rolling; contact the supplier.
    - Insulate from steel in salt water to avoid galvanic attack (Wikipedia, group statement).
  good_for:
    - Ceramic-to-metal seals in electronic devices, which Ulbrich lists as an application.
    - Transistor capsules, which Wikipedia lists as a use. No numeric capsule data were found.
    - Low-permeability parts, which Ulbrich names as a property of the alloy (the printed figure has no unit, so it is not recorded).
  watch_out:
    - Wikipedia says the alloy cannot be hot worked, and the Ulbrich sheet is silent on hot working.
    - The corrosion entries are qualitative. No corrosion rate or seawater test was found for this grade.
    - Mechanical values are minimums for annealed material, and the Ulbrich sheet says all data are typical values only.
    - The Ulbrich sheet and a supplier page disagree on density and melting point.
  verdict: Monel 404 is a low-permeability nickel-copper alloy for electronic seals and capsules. Its data come from one wire supplier, a supplier page and a short Wikipedia note, so confirm temper, product form and properties on a mill certificate before design.