{
  "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.\n",
  "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.",
    "designations": [],
    "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": {
    "environments": [],
    "stresses": [],
    "applications": [
      "thermal-control",
      "radiation-shielding",
      "electronics-and-chips"
    ]
  },
  "properties": [
    {
      "benchmark": "melting_point",
      "label": "Melting point, Rose's metal (50 Bi, 25 Pb, 25 Sn)",
      "value": 98,
      "bound": "exact",
      "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))",
      "source_detail": {
        "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"
      }
    },
    {
      "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)'",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, Newton's metal (Bi 50.0, Pb 31.2, Sn 18.8)",
      "value": 97,
      "bound": "exact",
      "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'",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, Field's metal (32.5 Bi, 51 In, 16.5 Sn)",
      "value": 62,
      "bound": "exact",
      "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)'",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, bismuth-lead eutectic (Bi 55.5, Pb 44.5)",
      "value": 124,
      "bound": "exact",
      "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",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Eutectic melting point, bismuth-lead (55.5 wt% Bi)",
      "value": 124,
      "bound": "exact",
      "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)'",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, bismuth-lead eutectic (Bi 55.5, Pb 44.5)",
      "value": 10.44,
      "bound": "exact",
      "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)",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, bismuth-lead eutectic (Bi 55.5, Pb 44.5)",
      "value": 44.1,
      "bound": "exact",
      "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)",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation at break, bismuth-lead eutectic (Bi 55.5, Pb 44.5)",
      "value": 37.5,
      "bound": "exact",
      "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)",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, bismuth-lead eutectic (Bi 55.5, Pb 44.5)",
      "value": 43,
      "bound": "exact",
      "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)",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat, bismuth-lead eutectic (Bi 55.5, Pb 44.5)",
      "value": 155,
      "bound": "exact",
      "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)",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, bismuth-lead eutectic (Bi 55.5, Pb 44.5)",
      "value": 4,
      "bound": "exact",
      "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)",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Eutectic melting point, bismuth-tin (Bi 58, Sn 42)",
      "value": 138,
      "bound": "exact",
      "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)",
      "source_detail": {
        "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"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, bismuth-tin (Bi 58, Sn 42)",
      "value": 8.56,
      "bound": "exact",
      "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)",
      "source_detail": {
        "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"
      }
    }
  ],
  "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",
      "abundance": "USGS: bismuth is produced most often as a byproduct during the processing of lead ores.",
      "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."
      ],
      "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%."
    }
  ],
  "media": [],
  "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."
  ],
  "story": {
    "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",
        "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.",
        "benchmark": "melting_point",
        "scope": "material",
        "value": "98 °C melting point"
      },
      {
        "label": "Melt lower",
        "line": "Field's metal, the bismuth-indium-tin eutectic, becomes liquid at about 62 °C (144 °F).",
        "benchmark": "melting_point",
        "scope": "material",
        "value": "62 °C melting point"
      },
      {
        "label": "Weight",
        "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.",
        "benchmark": "density",
        "scope": "material",
        "value": "10.44 g/cm3 density"
      },
      {
        "label": "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.",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material",
        "value": "44.1 MPa tensile"
      }
    ],
    "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",
        "scope": "material"
      },
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Tensile strength",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      }
    ],
    "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.",
    "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",
          "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.",
          "share_percent": 50
        },
        {
          "name": "Lead",
          "symbol": "Pb",
          "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.",
          "share_percent": 25
        },
        {
          "name": "Tin",
          "symbol": "Sn",
          "role": "A component that adds to the low melting point. The article gives 22 to 25% tin.",
          "share_percent": 25
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "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."
          }
        ],
        "level": 2,
        "verdict": "Lead and indium compounds are toxic"
      },
      {
        "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."
          }
        ]
      }
    ]
  },
  "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."
  },
  "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",
  "url": "https://spacemushroom.com/profiles/roses-metal/"
}