spore: profile
id: roses-metal
spore_version: 0.2
family: low-melting-metals-and-solders
name: Rose's metal, Newton's metal, Field's metal and the bismuth-lead and bismuth-tin eutectics
abbreviation: '-'
role: low-melting fusible alloys (about 62 to 138 °C, bismuth-based)
category: metals
type: heavy-metals
summary: |
  This profile covers a family of bismuth-based fusible alloys that melt well below 150 °C. Rose's metal is a bismuth-lead-tin alloy of nominal composition 50% bismuth, 25% lead and 25% tin by mass, with a melting point of 98 °C in the Wikipedia table and 94 to 98 °C in its article text. It was discovered by the German chemist Valentin Rose the Elder. Newton's metal (Bi 50.0, Pb 31.2, Sn 18.8) melts at 97 °C and was written about as a shielding material for radiotherapy. Field's metal is not a bismuth-lead or bismuth-tin alloy: it is a bismuth-indium-tin eutectic (32.5% Bi, 51% In, 16.5% Sn) that melts at about 62 °C, and it contains no lead or cadmium. The two binary eutectics are the bismuth-lead alloy 55.5% Bi with 44.5% Pb (melting at 124 °C in the OECD-NEA review and in a supplier page, and 125 °C in the Wikipedia table; the 45/55 figure in the brief is the same eutectic rounded), and the bismuth-tin alloy 58% Bi with 42% Sn at 138 °C. The bismuth-tin eutectic is listed in the AIM solder table and has a density of 8.56 g/cm3 on a Goodfellow page. Physical property data from a supplier exist only for the bismuth-lead eutectic (also in the OECD-NEA review) and the bismuth-tin eutectic. For Rose's metal, Newton's metal and Field's metal, only melting points and compositions were read; no density, thermal or tensile value could be read from an open page.
best_for: Low-temperature fusible releases and heat-transfer baths. Rose's metal is used as a heat-transfer medium in heating baths, and Newton's metal was proposed as easily shaped radiotherapy shielding
weakest_at: Field's metal is costly because indium is expensive. Lead-bearing alloys carry lead toxicity, and few physical or corrosion data were found for the solid alloys
identity:
  formula: Rose's metal and Newton's metal are bismuth-lead-tin alloys (Rose's nominal 50 Bi, 25 Pb, 25 Sn by mass; Newton's 50.0 Bi, 31.2 Pb, 18.8 Sn). Field's metal is a bismuth-indium-tin eutectic (32.5 Bi, 51 In, 16.5 Sn). The bismuth-lead eutectic is 55.5 Bi with 44.5 Pb, and the bismuth-tin eutectic is 58 Bi with 42 Sn. All are alloys, not compounds.
  source: wikipedia-fusible-alloy
  where: Well-known alloys table (Rose's metal, Field's metal, Wood's metal rows) and Other alloys table (Newton's metal, Bi-Pb and Bi-Sn rows)
tags:
  applications:
    - thermal-control
    - radiation-shielding
    - electronics-and-chips
  stresses: []
  environments: []
properties:
  - benchmark: melting_point
    label: Melting point, Rose's metal (50 Bi, 25 Pb, 25 Sn)
    value: 98
    unit: °C
    scope: material
    conditions:
      composition: 50 % Bi, 25 % Pb, 25 % Sn by mass (the composition the table prints)
      basis: eutectic flag printed as No; the article text gives a range (see the next row)
    method: Value in the well-known alloys table of an encyclopedia article (secondary source; underlying measurement not named)
    status: ground
    source: wikipedia-fusible-alloy
    where: Well-known alloys table, Rose's metal row (98 °C (208 °F))
  - benchmark: melting_point
    label: Melting range, Rose's metal (article text)
    value: 94
    value_high: 98
    bound: range
    unit: °C
    scope: material
    conditions:
      composition: 50 % Bi, 25 to 28 % Pb, 22 to 25 % Sn by mass (the article text range)
    method: Stated in the lead section of an encyclopedia article (secondary source; underlying measurement not named)
    status: ground
    note: The article text gives the wider composition range; the table uses the 50/25/25 composition, which gives 98 °C.
    source: wikipedia-roses-metal
    where: 'Lead section: ''Its melting point is between 94 and 98 °C (201 and 208 °F)'''
  - benchmark: melting_point
    label: Melting point, Newton's metal (Bi 50.0, Pb 31.2, Sn 18.8)
    value: 97
    unit: °C
    scope: material
    conditions:
      composition: 8 parts Bi, 5 parts Pb, 3 parts Sn by weight (the article); Bi 50.0, Pb 31.2, Sn 18.8 in the table
    method: Stated in the lead section of an encyclopedia article (secondary source)
    status: ground
    source: wikipedia-newtons-metal
    where: 'Lead section: ''its melting point is 97 °C'''
  - benchmark: melting_point
    label: Melting point, Field's metal (32.5 Bi, 51 In, 16.5 Sn)
    value: 62
    unit: °C
    scope: material
    conditions:
      composition: 32.5 % Bi, 51 % In, 16.5 % Sn by mass
      basis: stated as approximately 62 °C (144 °F)
    method: Stated in the lead section of an encyclopedia article (secondary source)
    status: ground
    note: The Wikipedia table prints 62 °C (144 °F) and marks the alloy as eutectic. Field's metal contains indium, not lead.
    source: wikipedia-fields-metal
    where: 'Lead paragraph: ''becomes liquid at approximately 62 °C (144 °F)'''
  - benchmark: melting_point
    label: Melting point, bismuth-lead eutectic (Bi 55.5, Pb 44.5)
    value: 124
    unit: °C
    scope: material
    conditions:
      composition: 55.5 Bi, 44.5 Pb by weight (eutectic)
    method: Value printed on a supplier product page for the 55.5/44.5 eutectic
    status: ground
    note: The Wikipedia Other alloys table prints 125 °C for the same composition and an OECD-NEA review passage prints 123.5 °C. The OECD review also gives 124 °C (397 K) in its phase-diagram text, and the value in this row is the supplier's.
    source: goodfellow-bipb
    where: 'Thermal Properties table, Melting point ( C) row: 124'
  - benchmark: melting_point
    label: Eutectic melting point, bismuth-lead (55.5 wt% Bi)
    value: 124
    unit: °C
    scope: material
    conditions:
      composition: 55.5 wt% Bi, 44.5 wt% Pb (eutectic)
    method: Value stated in the phase-diagram description of an OECD-NEA review chapter on lead-bismuth thermophysical properties
    status: ground
    note: The same chapter quotes the eutectic as 124 C (397 K) in its diagram text; it also records a historical value of 123.5 C for the 55.5 % Bi eutectic in its text.
    source: oecd-nea-lbe
    where: 'Section 2.1 (Introduction) and the figure text on the bismuth-lead phase diagram: ''an eutectic point at 55.5 wt.% Bi with a melting temperature of 124C (397 K)'''
  - benchmark: density
    label: Density, bismuth-lead eutectic (Bi 55.5, Pb 44.5)
    value: 10.44
    unit: g/cm3
    scope: material
    conditions:
      composition: Bi 55.5 / Pb 44.5
      temperature: not stated on the page
    method: Value printed on a supplier product page in the physical properties table
    status: ground
    source: goodfellow-bipb
    where: Physical Properties table, Density row (10.44)
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, bismuth-lead eutectic (Bi 55.5, Pb 44.5)
    value: 44.1
    unit: MPa
    scope: material
    conditions:
      composition: Bi 55.5 / Pb 44.5
      test_method: not stated on the page
      product_form: not stated on the page
    method: Value printed on a supplier product page in the mechanical properties table
    status: ground
    note: The supplier prints no test method or form, so treat the value as indicative. The source does not give a temperature.
    source: goodfellow-bipb
    where: Mechanical Properties table, Tensile strength (MPa) row (44.1)
  - benchmark: elongation
    label: Elongation at break, bismuth-lead eutectic (Bi 55.5, Pb 44.5)
    value: 37.5
    unit: '%'
    scope: material
    conditions:
      composition: Bi 55.5 / Pb 44.5
      test_method: not stated on the page
    method: Value printed on a supplier product page in the mechanical properties table
    status: ground
    source: goodfellow-bipb
    where: Mechanical Properties table, Elongation at break (%) row (37.5)
  - benchmark: electrical_resistivity
    label: Electrical resistivity, bismuth-lead eutectic (Bi 55.5, Pb 44.5)
    value: 43
    unit: µOhmcm
    scope: material
    conditions:
      composition: Bi 55.5 / Pb 44.5
      temperature: not stated on the page
    method: Value printed on a supplier product page, copied with the unit as printed (µOhmcm)
    status: ground
    source: goodfellow-bipb
    where: Electrical Properties table, Electrical resistivity row (43)
  - benchmark: specific_heat
    label: Specific heat, bismuth-lead eutectic (Bi 55.5, Pb 44.5)
    value: 155
    unit: J/kg-K
    scope: material
    conditions:
      composition: Bi 55.5 / Pb 44.5
      temperature: 23 °C
    method: Value printed on a supplier product page; the page prints the unit as J K-1 kg-1
    status: ground
    source: goodfellow-bipb
    where: Thermal Properties table, Specific heat row (155 at 23 °C)
  - benchmark: thermal_conductivity
    label: Thermal conductivity, bismuth-lead eutectic (Bi 55.5, Pb 44.5)
    value: 4
    unit: W/m-K
    scope: material
    conditions:
      composition: Bi 55.5 / Pb 44.5
      temperature: 85 °C
    method: Value printed on a supplier product page; the page prints the unit as W m-1 K-1
    status: ground
    source: goodfellow-bipb
    where: Thermal Properties table, Thermal conductivity row (4 at 85 °C)
  - benchmark: melting_point
    label: Eutectic melting point, bismuth-tin (Bi 58, Sn 42)
    value: 138
    unit: °C
    scope: material
    conditions:
      composition: Bi 58 / Sn 42 (eutectic)
    method: Value printed on the AIM Solder alloy information sheet, specialty solder table
    status: ground
    source: aim-alloy-information
    where: Specialty solder alloys table, Bi58 row (58 Bi, 42 Sn, melting point 138 °C)
  - benchmark: density
    label: Density, bismuth-tin (Bi 58, Sn 42)
    value: 8.56
    unit: g/cm3
    scope: material
    conditions:
      composition: Bi 58 / Sn 42
      temperature: not stated on the page
    method: Value printed on a supplier product page in the physical properties table
    status: ground
    note: The AIM sheet prints the density in pounds per cubic inch (.3090) and is not converted here.
    source: goodfellow-bisn
    where: Physical Properties table, Density (g cm-3) row (8.56)
corrosion:
  - environment: Molten bismuth-lead eutectic as a liquid-metal coolant (nuclear reactor and accelerator-driven systems)
    headline: The OECD-NEA review expects the low melting point to give lower corrosion rates, but it quotes no number.
    effect: The review says that LBE's low melting temperature of about 397 K (about 124 °C) results in lower corrosion rates and in easier maintenance. It gives no corrosion figure, and the statement applies to the molten alloy in a reactor, not to solid parts.
    rating: unknown
    conditions:
      basis: Qualitative statement in the introduction of a thermophysical-properties chapter; no test condition is given
      composition: Bi 55.5 wt% / Pb 44.5 wt% (LBE)
    source: oecd-nea-lbe
    where: Section 2.1 (Introduction)
risks:
  hazards:
    - text: Wikipedia says lead is a highly poisonous metal, whether inhaled or swallowed, affecting almost every organ and system. Rose's metal, Newton's metal and the bismuth-lead eutectic all contain lead.
      ghs: []
      source: wikipedia-lead
      where: Toxicity section
    - text: 'PubChem reports ECHA notifications for elemental lead: H360FD (may damage fertility; may damage the unborn child), H362 (may cause harm to breast-fed children), H400 and H410 (very toxic to aquatic life), with signal word Danger. Reproductive toxicity category Repr. 1A is reported for 84.4% of company reports.'
      ghs:
        - H360FD
        - H362
        - H400
        - H410
      source: pubchem-lead
      where: GHS Classification section, Hazard Statements and Regulation (EC) 1272/2008 classes (CID 5352425)
    - text: 'PubChem reports for elemental indium: signal word Danger, with H302, H312, H315, H319, H332, H335 and H372 (H372 is reported for 63.3% of company reports). It also records that 69 of 371 company reports say the substance does not meet GHS criteria. Field''s metal contains about 51% indium by mass.'
      ghs:
        - H302
        - H312
        - H315
        - H319
        - H332
        - H335
        - H372
      source: pubchem-indium
      where: GHS Classification section, hazard statements with percentages (CID 5359967)
    - text: Wikipedia says indium compounds are toxic when inhaled or injected into the bloodstream, although they are poorly absorbed after ingestion. It notes an overview that found no evidence of a health hazard from industrial use of indium.
      ghs: []
      source: wikipedia-indium
      where: Occurrence and production (toxicity sentence in the introduction)
    - text: 'Wikipedia says elemental bismuth has unusually low toxicity for a heavy metal. PubChem''s bismuth record has no GHS classification for the element: 324 of 382 company reports say it does not meet GHS criteria.'
      ghs: []
      source: pubchem-bismuth
      where: Toxicology and GHS Classification sections (CID 5359367)
  failure_risks:
    - mode: Melting of Rose's metal
      trigger: Temperature at or above about 94 to 98 °C
      consequence: The alloy liquefies. This is the intended action for fusible plugs and for filling tubes that are bent after melting, but a part in service above that temperature loses its shape and load capacity.
      severity: moderate
      source: wikipedia-roses-metal
      where: Lead section (melting range) and Uses section (tube filling)
    - mode: Exposure to lead from fume or dust
      trigger: Melting or machining a lead-bearing alloy (Rose's, Newton's or bismuth-lead) without controls
      consequence: Lead is highly poisonous whether inhaled or swallowed, and PubChem's ECHA aggregate for lead reports reproductive-toxicity hazard codes.
      severity: high
      source: wikipedia-lead
      where: Toxicity section; PubChem GHS Classification (CID 5352425)
    - mode: Joint failure when bismuth-tin solder is mixed with lead-tin solder
      trigger: Combining the bismuth-rich eutectic with lead-tin solder in one joint
      consequence: Wikipedia says the combination may dramatically lower the melting point and lead to joint failure.
      severity: high
      source: wikipedia-fusible-alloy
      where: Other alloys table, Bi58 note
    - mode: Exposure to indium from heated or dusty Field's metal
      trigger: Melting Field's metal or handling indium-rich dust
      consequence: Indium compounds are toxic when inhaled, according to Wikipedia. The liquid metal and the dust were not tested in any source read.
      severity: moderate
      source: wikipedia-indium
      where: Occurrence and production (toxicity sentence in the introduction)
  side_effects: []
  handling:
    - text: PubChem's lead record lists precautionary codes P260, P264, P270 and P280 (the code text is not quoted here).
      source: pubchem-lead
      where: GHS Classification section, Precautionary Statement Codes
    - text: Wikipedia says lead is toxic whether inhaled or swallowed, so do not melt, cut or grind lead-bearing alloys without ventilation and dust control.
      source: wikipedia-lead
      where: Toxicity section
  mitigations: []
uses:
  - application: thermal-control
    device: Heat-transfer medium in heating baths
    example: Wikipedia says Rose's metal is used as a heat-transfer medium in heating baths. This is a ground laboratory use.
    source: wikipedia-roses-metal
    where: Uses section, third use listed
  - application: radiation-shielding
    device: Easily shaped shielding for radiotherapy
    example: Wikipedia says Newton's metal is comparable to Cerrobend without Cerrobend's cadmium, which has encouraged its use for easily shaped shielding during radiotherapy. This is a ground medical use, not a space use.
    source: wikipedia-newtons-metal
    where: Lead section, second and third sentences
  - application: electronics-and-chips
    device: Low-temperature solder (bismuth-tin eutectic)
    example: The AIM Solder alloy sheet lists the Bi58 alloy, with melting point 138 °C, in its specialty solder table. The source does not describe a specific electronics use.
    source: aim-alloy-information
    where: Specialty solder alloys table, Bi58 row
supply:
  - subject: Bismuth
    producers:
      - country: China
        share_percent: 88
        year: 2025
      - country: Republic of Korea
        share_percent: 6.3
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals
        listed: true
    recycling: 'USGS: recycled bismuth-containing alloy scrap was estimated to compose up to 10% of U.S. bismuth apparent consumption for 2021 to 2025.'
    substitutes:
      - 'USGS: cadmium, indium, lead and tin can partially replace bismuth in low-temperature solders; glycerin-filled glass bulbs can replace bismuth alloys in triggering devices for fire sprinklers.'
    abundance: 'USGS: bismuth is produced most often as a byproduct during the processing of lead ores.'
    source: usgs-mcs2026-bismuth
    where: World Refinery Production table (2025; the China 88% share is printed in the Events paragraph; Republic of Korea 6.3% is 1,000 of 16,000 t, calculated by Space Mushroom); World Resources paragraph; Substitutes; critical list status from the USGS 2025 list page
  - subject: Lead
    producers:
      - country: China
        share_percent: 42.2
        year: 2025
      - country: Australia
        share_percent: 10.7
        year: 2025
      - country: Peru
        share_percent: 6.4
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals
        listed: true
    recycling: 'USGS: an estimated 1 million tons of secondary lead was produced in 2025, equivalent to 70% of apparent domestic consumption, mostly from lead-acid battery scrap.'
    substitutes:
      - 'USGS: plastics have reduced the use of lead in cable covering and cans, and steel and zinc are common substitutes for lead in wheel weights.'
    source: usgs-mcs2026-lead
    where: World Mine Production and Reserves table (2025e, thousand metric tons of lead content; world total 4,500; shares calculated by Space Mushroom from China 1,900, Australia 480 and Peru 290); Recycling; Substitutes; critical list status from the USGS 2025 list page
  - subject: Tin
    producers:
      - country: China
        share_percent: 24.5
        year: 2025
      - country: Indonesia
        share_percent: 21
        year: 2025
      - country: Peru
        share_percent: 11.4
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals
        listed: true
    recycling: 'USGS: about 17,000 tons of tin from old and new scrap was estimated to have been recycled in 2025, accounting for 22% of apparent consumption.'
    substitutes:
      - 'USGS: epoxy resins for solder are listed among materials that substitute for tin, and aluminum, glass, paper, plastic or tin-free steel substitute for tin in cans.'
    source: usgs-mcs2026-tin
    where: World Mine Production table (2025e, world total 290,000 t; shares calculated by Space Mushroom from China 71,000, Indonesia 61,000 and Peru 33,000); Recycling; Substitutes; critical list status from the USGS 2025 list page
  - subject: Indium
    producers:
      - country: China
        share_percent: 70
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals
        listed: true
    recycling: 'USGS: indium is most commonly recovered from ITO scrap in Japan and the Republic of Korea.'
    substitutes: []
    source: usgs-mcs2026-indium
    where: Events paragraph (China accounts for 70% of the world total); Recycling; critical list status from the USGS 2025 list page. Import sources for 2021 to 2024 were Republic of Korea 25%, Japan 22%, China 12% and Canada 11%.
documents:
  - title: 'Mineral Commodity Summaries 2026: Bismuth (USGS)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-bismuth.pdf
    year: 2026
  - title: 'Mineral Commodity Summaries 2026: Lead (USGS)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lead.pdf
    year: 2026
  - title: 'Mineral Commodity Summaries 2026: Tin (USGS)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf
    year: 2026
  - title: 'Mineral Commodity Summaries 2026: Indium (USGS)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-indium.pdf
    year: 2026
  - title: About the 2025 List of Critical Minerals (USGS)
    type: report
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
  - title: Fusible alloy (encyclopedia article, well-known alloys and other alloys tables)
    type: database
    url: https://en.wikipedia.org/wiki/Fusible_alloy
    year: 2026
  - title: Rose's metal (encyclopedia article)
    type: database
    url: https://en.wikipedia.org/wiki/Rose%27s_metal
    year: 2026
  - title: Field's metal (encyclopedia article)
    type: database
    url: https://en.wikipedia.org/wiki/Field%27s_metal
    year: 2026
  - title: Newton's metal (encyclopedia article)
    type: database
    url: https://en.wikipedia.org/wiki/Newton%27s_metal
    year: 2026
  - title: Bismuth (encyclopedia article)
    type: database
    url: https://en.wikipedia.org/wiki/Bismuth
    year: 2026
  - title: Lead (encyclopedia article, toxicity)
    type: database
    url: https://en.wikipedia.org/wiki/Lead
    year: 2026
  - title: Indium (encyclopedia article, occurrence and toxicity)
    type: database
    url: https://en.wikipedia.org/wiki/Indium
    year: 2026
  - title: Bismuth-lead alloy pellets, 55.5:44.5 eutectic (Goodfellow product page)
    type: datasheet
    url: https://www.goodfellow.com/usa/bismuth-lead-alloy-pellets-bi55-5-pb44-5-group
    year: 2026
  - title: Bismuth/tin alloy ingot, Bi58/Sn42 (Goodfellow product page)
    type: datasheet
    url: https://www.goodfellow.com:443/p/bi11-lp-000100/bismuth-tin-alloy-ingot
    year: 2026
  - title: Alloy information, common and specialty solder alloys (AIM Solder)
    type: datasheet
    url: https://aimsolder.com/wp-content/uploads/legacy-files/alloy_information.pdf
    year: 2026
  - title: 'Lead-bismuth eutectic: thermophysical and electric properties, chapter 2 (OECD-NEA, 2007)'
    type: report
    url: https://www.oecd-nea.org/science/reports/2007/pdf/chapter2.pdf
    year: 2007
  - title: 'PubChem compound record: Lead (CID 5352425), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/5352425
    year: 2026
  - title: 'PubChem compound record: Indium (CID 5359967), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Indium
    year: 2026
  - title: 'PubChem compound record: Bismuth (CID 5359367), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Bismuth
    year: 2026
gaps:
  - 'Rose''s metal: no density, thermal conductivity, specific heat, tensile strength or elongation was read on an open page. The Thermo Fisher, Sigma-Aldrich and American Elements pages were blocked (HTTP 403 or no DNS), and the search snippets are not used as values.'
  - 'Rose''s metal: the Thermo Fisher listing reports 95 to 96 °C and hazard statements, but its page could not be opened, so that value is not recorded.'
  - 'Field''s metal: no density, thermal conductivity or tensile value was read. American Elements (density) and Fisher Scientific were blocked; university papers on its thermophysical properties were seen only as search results.'
  - 'Field''s metal: a materials paper in search results gives a different melting temperature, which was not fetched, so the 62 °C value stands alone.'
  - 'Newton''s metal: density, thermal and mechanical data were not found. The 2007 paper on Newton''s metal as shielding (Radiation Effects and Defects in Solids) returned HTTP 403.'
  - 'Bismuth-tin (Bi 58, Sn 42): the tensile strength on American Elements (blocked) was not read, so no mechanical value is recorded for it.'
  - 'Bismuth-lead eutectic: the Brinell hardness of 15 is printed without a unit, so it is left out. The 44.1 MPa tensile value and the 37.5% elongation have no test method on the page.'
  - 'Bismuth-lead eutectic: the eutectic melting point is 124 °C in the Goodfellow page and the OECD-NEA review, 125 °C in the Wikipedia table, and 123.5 °C in one OECD-NEA passage. All are recorded as printed.'
  - 'Rose''s metal composition: the Wikipedia table prints 50/25/25 and the article text gives 25 to 28% lead and 22 to 25% tin. Both are recorded as printed.'
  - No corrosion, oxidation or galvanic-corrosion data were found for the solid alloys. The only corrosion statement is the qualitative OECD-NEA remark on molten LBE.
  - No UNS, EN, ASTM or JIS designation was found for Rose's, Newton's or Field's metal in any source read.
  - No space, vacuum, outgassing, radiation or thermal-cycling data were found. The uses listed are ground uses.
  - Field's metal is a bismuth-indium-tin alloy, not bismuth-lead. The brief's bismuth-lead and bismuth-tin scope does not include it, so its data are kept separate in the summary.
sources:
  wikipedia-fusible-alloy:
    title: Fusible alloy, Wikipedia (well-known alloys table and other alloys table)
    url: https://en.wikipedia.org/wiki/Fusible_alloy
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  wikipedia-roses-metal:
    title: Rose's metal, Wikipedia (lead section, uses, history)
    url: https://en.wikipedia.org/wiki/Rose%27s_metal
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  wikipedia-fields-metal:
    title: Field's metal, Wikipedia (lead paragraph, toxicity, applications)
    url: https://en.wikipedia.org/wiki/Field%27s_metal
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  wikipedia-newtons-metal:
    title: Newton's metal, Wikipedia (lead section)
    url: https://en.wikipedia.org/wiki/Newton%27s_metal
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  wikipedia-bismuth:
    title: Bismuth, Wikipedia (physical properties and toxicity)
    url: https://en.wikipedia.org/wiki/Bismuth
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  wikipedia-lead:
    title: Lead, Wikipedia (toxicity)
    url: https://en.wikipedia.org/wiki/Lead
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  wikipedia-indium:
    title: Indium, Wikipedia (occurrence and toxicity)
    url: https://en.wikipedia.org/wiki/Indium
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  goodfellow-bipb:
    title: Bismuth-lead alloy pellets, 55.5:44.5 eutectic (Goodfellow Metals)
    url: https://www.goodfellow.com/usa/bismuth-lead-alloy-pellets-bi55-5-pb44-5-group
    kind: datasheet
    license: supplier page, cited not reproduced
  goodfellow-bisn:
    title: Bismuth/tin alloy ingot, Bi58/Sn42 (Goodfellow Metals)
    url: https://www.goodfellow.com:443/p/bi11-lp-000100/bismuth-tin-alloy-ingot
    kind: datasheet
    license: supplier page, cited not reproduced
  aim-alloy-information:
    title: Alloy information, common and specialty solder alloys (AIM Solder)
    url: https://aimsolder.com/wp-content/uploads/legacy-files/alloy_information.pdf
    kind: datasheet
    license: supplier document, cited not reproduced
  oecd-nea-lbe:
    title: 'Lead-bismuth eutectic: thermophysical and electric properties, chapter 2 (OECD Nuclear Energy Agency, 2007)'
    url: https://www.oecd-nea.org/science/reports/2007/pdf/chapter2.pdf
    kind: report
    license: OECD-NEA, cited not reproduced
  usgs-mcs2026-bismuth:
    title: 'Mineral Commodity Summaries 2026: Bismuth (U.S. Geological Survey)'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-bismuth.pdf
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-lead:
    title: 'Mineral Commodity Summaries 2026: Lead (U.S. Geological Survey)'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lead.pdf
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-tin:
    title: 'Mineral Commodity Summaries 2026: Tin (U.S. Geological Survey)'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-indium:
    title: 'Mineral Commodity Summaries 2026: Indium (U.S. Geological Survey)'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-indium.pdf
    kind: report
    license: public domain (USGS)
  usgs-crit2025:
    title: About the 2025 List of Critical Minerals (U.S. Geological Survey)
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    kind: report
    license: public domain (USGS)
  pubchem-lead:
    title: 'PubChem compound record: Lead (CID 5352425), GHS classification'
    id: CID 5352425
    url: https://pubchem.ncbi.nlm.nih.gov/compound/5352425
    kind: database
    license: public domain (NCBI)
  pubchem-indium:
    title: 'PubChem compound record: Indium (CID 5359967), GHS classification'
    id: CID 5359967
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Indium
    kind: database
    license: public domain (NCBI)
  pubchem-bismuth:
    title: 'PubChem compound record: Bismuth (CID 5359367), GHS classification'
    id: CID 5359367
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Bismuth
    kind: database
    license: public domain (NCBI)
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 14
  unreachable: 4
  caveats: 5
  note: 'Read by an AI assistant on 2026-10-26. Fourteen numeric properties are sourced: four melting points (Rose''s metal 98 and 94 to 98, Newton''s 97, Field''s 62), two bismuth-lead eutectic melting points (124 from a supplier and the OECD-NEA review), bismuth-lead density, tensile, elongation, resistivity, specific heat and conductivity (supplier), and bismuth-tin melting point (AIM) and density (supplier). Unreachable: Thermo Fisher, Sigma-Aldrich, American Elements (blocked) and the 2007 Newton''s metal paper (HTTP 403). Caveats: the Bi-Pb values come from one supplier and carry no test method; the Wikipedia values have no test conditions; Field''s metal is not bismuth-lead; no corrosion data for solid alloys; the Rose''s metal density is missing.'
story:
  recipe:
    line: Rose's metal is a bismuth-lead-tin alloy, not a eutectic, with nominal composition 50% bismuth, 25% lead and 25% tin by mass (Wikipedia table). The article gives a wider range of 25 to 28% lead and 22 to 25% tin. The sources read do not describe how the alloy is made.
    parts:
      - name: Bismuth
        symbol: Bi
        share_percent: 50
        role: The largest share. It makes up half the alloy and gives it a low melting point. Wikipedia describes elemental bismuth as having unusually low toxicity for a heavy metal.
      - name: Lead
        symbol: Pb
        share_percent: 25
        role: A heavy, soft component. Its share is 25 to 28% in the article text. Lead is the reason for most of the toxicity warnings in this profile.
      - name: Tin
        symbol: Sn
        share_percent: 25
        role: A component that adds to the low melting point. The article gives 22 to 25% tin.
  risk_groups:
    - title: For people
      level: 2
      verdict: Lead and indium compounds are toxic
      lead: The alloys that contain lead carry lead's hazard codes. Field's metal contains indium, whose compounds are toxic when inhaled, according to Wikipedia.
      points:
        - label: Lead
          line: PubChem's ECHA aggregate for lead reports H360FD, H362, H400 and H410, with signal word Danger. Wikipedia says lead is poisonous whether inhaled or swallowed.
        - label: Indium
          line: PubChem's indium record lists H302, H312, H315, H319, H332, H335 and H372 with signal word Danger. Field's metal is about 51% indium.
        - label: Bismuth
          line: Wikipedia says elemental bismuth has unusually low toxicity for a heavy metal. PubChem's bismuth record has no GHS classification, with 324 of 382 company reports not meeting GHS criteria.
    - title: If it overheats
      lead: These alloys melt well below 150 °C, so a part in service can lose its shape or release its load above the melting point.
      points:
        - label: Rose's metal
          line: The alloy melts between 94 and 98 °C (article), and the Wikipedia table gives 98 °C for the 50/25/25 composition.
        - label: Newton's metal
          line: Newton's metal melts at 97 °C.
        - label: Field's metal
          line: Field's metal becomes liquid at about 62 °C (144 °F).
    - title: Handling and storage
      points:
        - label: Lead-bearing alloys
          line: PubChem's lead record lists precautionary codes P260, P264, P270 and P280. Wikipedia says lead is toxic whether inhaled or swallowed. Dust and fume control is advice, not a figure from the sources.
        - label: Solder mixing
          line: Wikipedia warns that combining the bismuth-tin eutectic with lead-tin solder may dramatically lower the melting point and lead to joint failure.
  why: 'Rose''s metal is a low-melting alloy of bismuth, lead and tin, and Newton''s metal is a close relative. Their melting points are low enough for heat-transfer baths and fusible releases. Field''s metal trades a lead-free composition for a lower melting point (about 62 °C) and a high cost, since indium is expensive. The bismuth-lead eutectic is the coolant alloy in the OECD-NEA review, and the bismuth-tin eutectic is listed in the AIM solder table. Wikipedia gives the history of Rose''s metal: the German chemist Valentin Rose the Elder discovered it.'
  uses:
    - where: Heat-transfer baths
      line: Wikipedia says Rose's metal is used as a heat-transfer medium in heating baths. It is also used as a solder, to set cast iron railings in stone, and as a filler that keeps tubes from crimping while they are bent.
    - where: Radiation treatment shielding
      line: Wikipedia says Newton's metal is comparable to Cerrobend without Cerrobend's cadmium, which has encouraged its use for easily shaped shielding in radiotherapy. This is a ground medical use.
    - where: Low-temperature solder
      line: The AIM Solder alloy sheet lists the bismuth-tin eutectic, Bi58 with 138 °C melting point, among its specialty solder alloys. Wikipedia notes the alloy has reasonable shear strength and fatigue properties.
  can_do:
    - label: Melt low
      value: 98 °C melting point
      benchmark: melting_point
      line: Rose's metal melts at 98 °C in the Wikipedia table and between 94 and 98 °C in its article. Newton's metal melts at 97 °C.
    - label: Melt lower
      value: 62 °C melting point
      benchmark: melting_point
      line: Field's metal, the bismuth-indium-tin eutectic, becomes liquid at about 62 °C (144 °F).
    - label: Weight
      value: 10.44 g/cm3 density
      benchmark: density
      line: The bismuth-lead eutectic has a density of 10.44 g/cm3 on a supplier page. The bismuth-tin eutectic is 8.56 g/cm3 on another supplier page. No density is recorded for Rose's metal.
    - label: Strength
      value: 44.1 MPa tensile
      benchmark: ultimate_tensile_strength
      line: The bismuth-lead eutectic has a tensile strength of 44.1 MPa on a supplier page, without a test method. It stretches 37.5% before it breaks.
  compare: These alloys sit at the low-melting end of the metal family. Rose's metal and Newton's metal melt at 97 to 98 °C, 27 to 28 °C above Wood's metal (70 °C in the Wikipedia table), and both carry lead rather than cadmium. Field's metal, at about 62 °C, is the lowest of the group, but it is an indium alloy and costs more. The bismuth-lead eutectic at 124 °C and the bismuth-tin eutectic at 138 °C sit above Rose's metal. For the values that exist, the bismuth-lead eutectic is the most complete record.
  compare_rows:
    - label: Melting point
      benchmark: melting_point
    - label: Density
      benchmark: density
    - label: Tensile strength
      benchmark: ultimate_tensile_strength
  handling:
    - Treat lead-bearing alloys as toxic. Wikipedia says lead is poisonous whether inhaled or swallowed. Dust and fume control is advice, not a figure from the sources.
    - 'Keep the composition in view: the Rose''s metal melting point in Wikipedia is 98 °C for 50/25/25, while the article gives 94 to 98 °C.'
    - Do not mix bismuth-tin solder with lead-tin solder in one joint, since the mixed alloy may fail (Wikipedia).
  good_for:
    - Heat-transfer baths held near 98 °C, where Rose's metal is used (Wikipedia).
    - Fusible releases near 62 °C, where Field's metal is used as a low-melting, lead-free option (Wikipedia).
  watch_out:
    - 'Lead: Rose''s, Newton''s and the bismuth-lead eutectic contain lead, and PubChem records H360FD and H362 for lead.'
    - 'Indium cost: Field''s metal is costly, since its major component is indium, which Wikipedia says costs about double the price of silver.'
    - 'Few physical data: no density for Rose''s metal, and no thermal or tensile data for Rose''s, Newton''s or Field''s metal in any source read.'
  verdict: Rose's metal and Newton's metal are lead-containing fusible alloys that melt at 97 to 98 °C. Field's metal is a lead-free, indium-based alternative at 62 °C. The bismuth-lead and bismuth-tin eutectics have the most complete data. The physical data for the three named alloys are thin, and lead's toxicity is the main hazard.