{
  "spore": "profile",
  "id": "tin-antimony-babbitt",
  "spore_version": "0.2",
  "family": "low-melting-metals-and-solders",
  "name": "Tin-antimony babbitt (tin-base bearing metal)",
  "abbreviation": "Sn-Sb-Cu",
  "role": "soft bearing-lining alloy",
  "category": "metals",
  "type": "heavy-metals",
  "summary": "Tin-base babbitt is a soft alloy of tin with about 7.5% antimony and 3.5% copper (ASTM B23 Grade 2, nominal 89% tin). It is used as a thin running surface in plain bearings. The ASTM B23 Grade 2 grade has a density of 7.39 g/cm3, a solidus of 241 degC and a liquidus of 354 degC, a Brinell hardness of 24.5, and a chill-cast tensile strength of 77.0 MPa, according to the Kapp Alloy datasheet. Its elongation differs between two datasheets (18% on Kapp, 8.0% on Trotter), and the sheets give no test conditions for the Trotter figure.\n",
  "best_for": "Thin plain-bearing linings that must tolerate repeated loading: Wikipedia says combustion engines use tin-based babbitt because it withstands cyclic loading",
  "weakest_at": "Strength and temperature: a solidus of 241 degC, a Brinell hardness of 24.5 and 42.1 MPa compressive yield. Tin pest and antimony toxicity add cold and handling limits.",
  "identity": {
    "formula": "Tin-base babbitt ASTM B23 Grade 2: Sn 89, Sb 7.5, Cu 3.5 nominal (mass %), limits Sn 88 to 90, Sb 7 to 8, Cu 3 to 4, Pb up to 0.35. Lead-based babbitt BS 3332 Alloy G: Pb balance, Sn 4.5 to 6.5, Sb 14 to 17 (mass %). Pewter: tin 85 to 99, antimony about 5 to 10, copper about 2 (mass %); typical European casting pewter Sn 94, Cu 1, Sb 5.",
    "designations": [
      {
        "system": "ASTM",
        "code": "B23",
        "note": "Grade 2 tin-base babbitt (the Trotter sheet lists it as ASTM B23-00 Alloy 2)",
        "source": "kapp-grade2",
        "where": "Page title ASTM-B23 Grade 2 Tin Babbitt and specification section ASTM B23: Grade 2"
      }
    ],
    "source": "kapp-grade2",
    "where": "Chemical composition limits on the Kapp Alloy product page and the Nathan Trotter datasheet (Sn 89 / Sb 7.5 / Cu 3.5, Pb below 0.35); Wikipedia Babbitt metal (BS 3332 Alloy G) and Wikipedia Pewter (composition paragraphs)"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "mechanisms",
      "electronics-and-chips",
      "batteries"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density of tin-base babbitt, ASTM B23 Grade 2",
      "value": 7.39,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "composition": "ASTM B23 Grade 2, nominal Sn 89 / Sb 7.5 / Cu 3.5 (mass %)",
        "temperature": "not stated"
      },
      "method": "Value printed on the Kapp Alloy product page. The same page also prints the unit as mg/m3 once, which is a misprint.",
      "status": "ground",
      "source": "kapp-grade2",
      "where": "Physical properties, density row (7.39 g/cc, 0.267 lb/in3)",
      "source_detail": {
        "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
        "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
        "kind": "datasheet",
        "license": "vendor product page, cited not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Solidus to liquidus range, tin-base babbitt",
      "value": 241,
      "value_high": 354,
      "bound": "range",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "basis": "printed as 466-669 degF (241-354 degC)",
        "composition": "ASTM B23 Grade 2"
      },
      "method": "Range printed on the Kapp Alloy product page; the Trotter datasheet prints the same 466 and 669 degF as solidus and liquidus.",
      "status": "ground",
      "source": "kapp-grade2",
      "where": "Physical properties, melting range line (466-669 degF (241-354 degC))",
      "source_detail": {
        "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
        "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
        "kind": "datasheet",
        "license": "vendor product page, cited not reproduced"
      }
    },
    {
      "benchmark": "brinell_hardness",
      "label": "Brinell hardness, tin-base babbitt",
      "value": 24.5,
      "bound": "exact",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "ball": "10 mm",
        "load": "500 kg",
        "time": "30 s",
        "composition": "ASTM B23 Grade 2"
      },
      "method": "Value printed on the Kapp Alloy product page with its test conditions",
      "status": "ground",
      "note": "The name brinell_hardness is not in spores/property-canon.yaml and is used as it is.",
      "source": "kapp-grade2",
      "where": "Hardness row (24.5, 10 mm ball / 500 kg load - 30 sec)",
      "source_detail": {
        "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
        "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
        "kind": "datasheet",
        "license": "vendor product page, cited not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Ultimate tensile strength, chill cast at 20 degC",
      "value": 77,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "casting": "chill cast",
        "temperature": "20 degC (68 degF)",
        "composition": "ASTM B23 Grade 2"
      },
      "method": "Value in the chill-cast table of the Kapp Alloy product page",
      "status": "ground",
      "source": "kapp-grade2",
      "where": "Tensile table, chill cast row at 20 degC (77.0 MPa, 11,200 psi)",
      "source_detail": {
        "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
        "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
        "kind": "datasheet",
        "license": "vendor product page, cited not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Ultimate tensile strength, die cast",
      "value": 87,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "casting": "die cast, poured at 600 degF (315 degC) into a 302 degF (150 degC) mold",
        "composition": "ASTM B23 Grade 2"
      },
      "method": "Value printed on the Kapp Alloy product page, footnote and die-cast entry",
      "status": "ground",
      "source": "kapp-grade2",
      "where": "Tensile entry labelled Diecast (87.0 MPa, 12,600 psi)",
      "source_detail": {
        "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
        "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
        "kind": "datasheet",
        "license": "vendor product page, cited not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation at break, chill cast (Kapp)",
      "value": 18,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "casting": "chill cast",
        "temperature": "20 degC",
        "gage": "4 x (area)^1/2 gage length"
      },
      "method": "Value printed on the Kapp Alloy product page, chill-cast entry",
      "status": "ground",
      "source": "kapp-grade2",
      "where": "Elongation entry, chill cast (18% at break)",
      "source_detail": {
        "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
        "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
        "kind": "datasheet",
        "license": "vendor product page, cited not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, ASTM B23 Grade 2 datasheet (Trotter)",
      "value": 8,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "basis": "product data sheet, no test condition printed",
        "composition": "ASTM B23 Grade 2"
      },
      "method": "Value printed on the Nathan Trotter Grade 2 datasheet. It is lower than the chill-cast figure from Kapp, and the two sheets do not give matching test conditions.",
      "status": "ground",
      "source": "trotter-grade2",
      "where": "Physical properties, Elongation % row (8.0)",
      "source_detail": {
        "title": "Nathan Trotter & Co. product data sheet, ASTM Grade 2 Babbitt Metal (SPEC NO NT Grade 2 Babbitt, Rev. 3, 2015)",
        "id": "ASTM B23-00 Alloy 2 on the sheet",
        "url": "https://nathantrotter.com/wp-content/uploads/2020/09/Grade-2-Babbitt-Data.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Tensile elastic modulus, cast tin-base babbitt",
      "value": 52,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "test": "tension",
        "casting": "cast at 400 degC into a 100 degC mold"
      },
      "method": "Value in the mechanical properties table of the Kapp Alloy product page",
      "status": "ground",
      "source": "kapp-grade2",
      "where": "Elastic modulus row (52 GPa)",
      "source_detail": {
        "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
        "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
        "kind": "datasheet",
        "license": "vendor product page, cited not reproduced"
      }
    },
    {
      "benchmark": "fatigue_strength",
      "label": "Fatigue strength, chill cast tin-base babbitt",
      "value": 33,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "test": "R.R. Moore",
        "cycles": "2 x 10^7 (printed as 2 x 107)",
        "casting": "chill cast"
      },
      "method": "Value printed on the Kapp Alloy product page, fatigue entry",
      "status": "ground",
      "source": "kapp-grade2",
      "where": "Fatigue entry, R.R. Moore test (33.0 MPa, 4790 psi)",
      "source_detail": {
        "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
        "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
        "kind": "datasheet",
        "license": "vendor product page, cited not reproduced"
      }
    },
    {
      "benchmark": "compressive_yield_strength",
      "label": "Compressive yield strength, tin-base babbitt",
      "value": 42.1,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "set": "0.125% set",
        "composition": "ASTM B23 Grade 2"
      },
      "method": "Value printed on the Kapp Alloy product page, compressive entry",
      "status": "ground",
      "note": "The name compressive_yield_strength is not in spores/property-canon.yaml and is used as it is.",
      "source": "kapp-grade2",
      "where": "Compressive entry (42.1 MPa at 0.125% set)",
      "source_detail": {
        "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
        "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
        "kind": "datasheet",
        "license": "vendor product page, cited not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point of pure tin, for comparison with the babbitt",
      "value": 231.9,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "form": "pure tin",
        "pressure": "not stated"
      },
      "method": "Value listed in the melting point section of the PubChem record for tin",
      "status": "ground",
      "source": "pubchem-tin",
      "where": "Experimental Properties, melting point entries (231.9 degC)",
      "source_detail": {
        "title": "PubChem compound record: Tin (CID 5352426), experimental properties and GHS classification",
        "id": "CID 5352426",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON",
        "year": 2026,
        "kind": "database",
        "license": "PubChem (NCBI), public domain; sections attributed to ECHA, NITE-CMC and other databases"
      }
    },
    {
      "benchmark": "allotropic_transformation_temperature",
      "label": "Tin pest transition, white tin to grey tin",
      "value": 13.2,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "transformation": "white (beta) tin to grey (alpha) tin, at and below the temperature",
        "basis": "pure tin; the babbitt alloy is not tested"
      },
      "method": "Value printed in the allotropic transformation section of Wikipedia Tin pest",
      "status": "ground",
      "note": "The name allotropic_transformation_temperature is not in spores/property-canon.yaml and is used as it is.",
      "source": "wiki-tin-pest",
      "where": "Allotropic transformation section, At 13.2 degC (55.8 degF) and below",
      "source_detail": {
        "title": "Tin pest, Wikipedia (allotropic transformation at 13.2 degC, volume increase)",
        "url": "https://en.wikipedia.org/wiki/Tin_pest",
        "kind": "web",
        "license": "CC BY-SA 4.0, linked not reproduced"
      }
    },
    {
      "benchmark": "volume_change",
      "label": "Volume increase, white tin to grey tin",
      "value": 27,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "basis": "change from white (beta) to grey (alpha) tin",
        "composition": "pure tin"
      },
      "method": "Value printed in the allotropic transformation section of Wikipedia Tin pest",
      "status": "ground",
      "source": "wiki-tin-pest",
      "where": "Allotropic transformation section, a large volume increase of about 27%",
      "source_detail": {
        "title": "Tin pest, Wikipedia (allotropic transformation at 13.2 degC, volume increase)",
        "url": "https://en.wikipedia.org/wiki/Tin_pest",
        "kind": "web",
        "license": "CC BY-SA 4.0, linked not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point of antimony metal, the alloying element",
      "value": 630,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "form": "antimony metal",
        "pressure": "not stated"
      },
      "method": "Value listed in the melting point section of the PubChem record for antimony",
      "status": "ground",
      "source": "pubchem-antimony",
      "where": "Experimental Properties, melting point entries (630 degC)",
      "source_detail": {
        "title": "PubChem compound record: Antimony (CID 5354495), experimental properties and GHS classification",
        "id": "CID 5354495",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5354495/JSON",
        "year": 2026,
        "kind": "database",
        "license": "PubChem (NCBI), public domain; sections attributed to ECHA and other databases"
      }
    },
    {
      "benchmark": "density",
      "label": "Density of antimony metal, the alloying element",
      "value": 6.68,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "temperature": "20 degC",
        "form": "antimony metal"
      },
      "method": "Value printed in the density section of the PubChem record for antimony",
      "status": "ground",
      "source": "pubchem-antimony",
      "where": "Experimental Properties, density entries (6.68 g/cu cm at 20 degC)",
      "source_detail": {
        "title": "PubChem compound record: Antimony (CID 5354495), experimental properties and GHS classification",
        "id": "CID 5354495",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5354495/JSON",
        "year": 2026,
        "kind": "database",
        "license": "PubChem (NCBI), public domain; sections attributed to ECHA and other databases"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Below 13.2 degC, pure tin",
      "headline": "At and below 13.2 degC, white tin can change to grey tin with a volume increase of about 27%.",
      "effect": "Wikipedia gives 13.2 degC as the temperature at and below which the change happens. It says the change is slow to start because of a high activation energy and then speeds up, and it gives a volume increase of about 27%. No rate test on the babbitt alloy was found.",
      "rating": "moderate",
      "conditions": {
        "basis": "pure tin; alloy behaviour not stated in the source",
        "condition": "temperature at or below 13.2 degC"
      },
      "source": "wiki-tin-pest",
      "where": "Allotropic transformation section"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem notifications for antimony metal (CID 5354495): H301 (18.2%) toxic if swallowed, H302 (23.4%) harmful if swallowed, H332 (26.9%) harmful if inhaled, H351 (31.8%) suspected of causing cancer. Signal word Danger. 18.7% (140 of 748) of company reports say antimony does not meet GHS criteria.",
        "ghs": [
          "H301",
          "H302",
          "H332",
          "H351"
        ],
        "source": "pubchem-antimony",
        "where": "GHS Classification section, aggregated ECHA notifications (CID 5354495)"
      },
      {
        "text": "PubChem notifications for lead (CID 5352425): H360 (84.4%) may damage fertility or the unborn child, H372 (50.5%) causes damage to organs through prolonged or repeated exposure. Signal word Danger.",
        "ghs": [
          "H360",
          "H372"
        ],
        "source": "pubchem-lead",
        "where": "GHS Classification section, aggregated ECHA notifications (CID 5352425)"
      },
      {
        "text": "PubChem notifications for tin (CID 5352426): 72.9% (695 of 953) of company reports say tin does not meet GHS criteria. Where codes were given, H319 (24.2%) causes serious eye irritation and H335 (23.1%) may cause respiratory irritation. Signal word Warning. One further notification gives H372, damage to organs through prolonged or repeated exposure.",
        "ghs": [
          "H319",
          "H335",
          "H372"
        ],
        "source": "pubchem-tin",
        "where": "GHS Classification section, ECHA and NITE-CMC notifications (CID 5352426)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Overheating of the bearing lining",
        "trigger": "Operating temperature rises to the solidus of 241 degC",
        "consequence": "The Kapp datasheet gives a solidus of 241 degC and a liquidus of 354 degC. Above the solidus the alloy starts to melt, so the lining loses its strength before it reaches the liquidus. No failure test was read for this grade.",
        "severity": "high",
        "source": "kapp-grade2",
        "where": "Physical properties, melting range line"
      },
      {
        "mode": "Tin pest, transformation to grey tin",
        "trigger": "Exposure to temperatures at or below 13.2 degC",
        "consequence": "Wikipedia gives a volume increase of about 27% for the change to grey tin. The source gives no rate for the babbitt alloy, and the alloy is not tested for this change.",
        "severity": "moderate",
        "source": "wiki-tin-pest",
        "where": "Allotropic transformation section"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "The PubChem hazard codes above (H319, H335 and H372 for tin; H301, H302, H332 and H351 for antimony; H360 and H372 for lead) are for the elements, not for a babbitt grade. The sources read give no handling advice for the alloy; check the supplier's safety data sheet for the grade you buy.",
        "source": "pubchem-antimony",
        "where": "GHS Classification sections, CID 5354495, 5352425 and 5352426"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "mechanisms",
      "device": "Engine plain bearings (tin-based babbitt)",
      "example": "Wikipedia: internal combustion engines use Babbitt metal which is primarily tin-based because it can withstand cyclic loading. Poured Babbitt bearings were common in automotive applications until the mid-1950s.",
      "source": "wiki-babbitt",
      "where": "Lead introduction and Design, Modern section"
    },
    {
      "application": "mechanisms",
      "device": "Bearing metals, bronze and brass (babbitt, tinning)",
      "example": "USGS: babbitt, brass and bronze, and tinning together took 7% of tin use in the United States in 2025.",
      "source": "usgs-mcs2026-tin",
      "where": "Domestic Production and Use paragraph (uses percentages)"
    },
    {
      "application": "electronics-and-chips",
      "device": "Solder",
      "example": "USGS: solder took 11% of tin use in the United States in 2025.",
      "source": "usgs-mcs2026-tin",
      "where": "Domestic Production and Use paragraph (uses percentages)"
    },
    {
      "application": "batteries",
      "device": "Antimonial lead for lead-acid battery plates (antimony context)",
      "example": "USGS: secondary antimony was intended for the lead-acid battery industry, and antimonial lead and ammunition took 40% of antimony use in the United States in 2025.",
      "source": "usgs-mcs2026-antimony",
      "where": "Domestic Production and Use paragraph"
    }
  ],
  "supply": [
    {
      "subject": "Tin (mine production)",
      "producers": [
        {
          "country": "China",
          "share_percent": 24.5,
          "year": 2025
        },
        {
          "country": "Indonesia",
          "share_percent": 21,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 11.4,
          "year": 2025
        },
        {
          "country": "Brazil",
          "share_percent": 9.7,
          "year": 2025
        },
        {
          "country": "Congo (Kinshasa)",
          "share_percent": 9.3,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: about 17,000 tons of tin from old and new scrap was recycled in 2025, accounting for 22% of apparent consumption.",
      "substitutes": [
        "USGS: plastics for bearing metals that contain tin; epoxy resins for solder; alternative copper-base alloys for bronze."
      ],
      "source": "usgs-mcs2026-tin",
      "where": "World Mine Production and Reserves table, 2025e column (world total 290,000 t; shares calculated by Space Mushroom from China 71,000, Indonesia 61,000, Peru 33,000, Brazil 28,000 and Congo (Kinshasa) 27,000 over the world total); Recycling; Substitutes"
    },
    {
      "subject": "Antimony (mine production)",
      "producers": [
        {
          "country": "China",
          "share_percent": 36.4,
          "year": 2025
        },
        {
          "country": "Russia",
          "share_percent": 29.1,
          "year": 2025
        },
        {
          "country": "Tajikistan",
          "share_percent": 20,
          "year": 2025
        },
        {
          "country": "Bolivia",
          "share_percent": 4.5,
          "year": 2025
        },
        {
          "country": "Australia",
          "share_percent": 1.2,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: recycling supplied 12% of estimated domestic apparent consumption in 2025.",
      "substitutes": [
        "USGS: combinations of calcium, copper, selenium, sulfur, and tin are substitutes for alloys in lead-acid batteries."
      ],
      "source": "usgs-mcs2026-antimony",
      "where": "World Mine Production and Reserves table, 2025e column (world total 110,000 t; shares calculated by Space Mushroom from China 40,000, Russia 32,000, Tajikistan 22,000, Bolivia 5,000 and Australia 1,300 over the world total); Recycling; Substitutes"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Nathan Trotter & Co. product data sheet: ASTM Grade 2 Babbitt Metal (Rev. 3, 2015)",
      "type": "datasheet",
      "url": "https://nathantrotter.com/wp-content/uploads/2020/09/Grade-2-Babbitt-Data.pdf",
      "year": 2015
    },
    {
      "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt",
      "type": "datasheet",
      "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/"
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Antimony",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-antimony.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Tin",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf",
      "year": 2026
    },
    {
      "title": "PubChem compound record: Antimony (CID 5354495), GHS classification and experimental properties",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5354495/JSON",
      "year": 2026
    },
    {
      "title": "PubChem compound record: Lead (CID 5352425), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352425/JSON",
      "year": 2026
    },
    {
      "title": "PubChem compound record: Tin (CID 5352426), experimental properties and GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON",
      "year": 2026
    }
  ],
  "gaps": [
    "No standard text (ASTM B23 or BS 3332) was opened; the composition and property values come from vendor and distributor datasheets, not from the standards themselves.",
    "Elongation disagrees between the two datasheets (18% chill cast on Kapp, 8.0% on Trotter) and neither gives a full test set; both are recorded.",
    "The Kapp page prints the lead limit as 0.1000% in one list and 0.35% in the component table; the Trotter sheet prints below 0.35%. Only the 0.35% limit is used.",
    "Lead-based babbitt (BS 3332 Alloy G) is recorded for composition only. No property, corrosion or hazard value for a Sn-Pb-Sb babbitt was read in this run.",
    "Bismuth-tin alloys were not covered: no source for them was read in this run, so no value is given.",
    "Pewter composition is recorded from Wikipedia (general ranges). The Britannia metal composition was not printed on the page read, and no pewter property value was read.",
    "No corrosion test, ageing data or service-environment result was found for tin-antimony babbitt (oil, humidity, fuel or seawater).",
    "Tin whisker growth on tin-rich alloys was not read in this run (see the tin profile for the NASA source).",
    "No space-environment data (outgassing, vacuum, radiation, atomic oxygen, thermal cycling) was found for any tin-antimony alloy. No flight use of babbitt was found.",
    "Antimony critical-mineral status is not stated in the USGS MCS 2026 antimony text read here, and the USGS 2025 critical list was not opened, so critical_lists is left out.",
    "Brinell hardness on the Trotter sheet is printed as 24.5/12 with no test conditions, so only the Kapp row (10 mm ball, 500 kg, 30 s) is used.",
    "The Sn-Sb binary phase diagram and a thermal conductivity value for the babbitt grade were not found in a fetched source.",
    "UNS, EN and JIS designations for tin-base babbitt were not printed on any fetched page, so only the ASTM B23 Grade 2 designation is listed."
  ],
  "story": {
    "why": "Tin-base babbitt is a soft tin alloy with about 7.5% antimony and 3.5% copper. It is used as a thin running surface in plain bearings. The ASTM B23 Grade 2 grade has a density of 7.39 g/cm3, a solidus of 241 degC and a liquidus of 354 degC, and a Brinell hardness of 24.5 with a 10 mm ball and a 500 kg load. Its tensile strength is 77 MPa when chill cast. Wikipedia describes babbitt as a thin surface layer in a multi-metal bearing and says combustion engines use tin-based babbitt because it tolerates cyclic loading. Pure tin melts at 231.9 degC, so the babbitt starts to melt at a higher temperature than the pure metal.",
    "uses": [
      {
        "where": "Engine bearings",
        "line": "Internal combustion engines use babbitt that is primarily tin-based because it can withstand cyclic loading (Wikipedia). Poured babbitt bearings were common in cars until the mid-1950s."
      },
      {
        "where": "Bearing metals, solder and tinning",
        "line": "Babbitt, brass and bronze, and tinning together took 7% of U.S. tin use in 2025, and solder took 11% (USGS)."
      },
      {
        "where": "Lead-acid batteries (antimony)",
        "line": "Antimonial lead and ammunition took 40% of U.S. antimony use in 2025, and secondary antimony was intended for the lead-acid battery industry (USGS)."
      }
    ],
    "can_do": [
      {
        "label": "Melt range",
        "line": "The tin-base babbitt starts to melt at 241 degC and is fully liquid at 354 degC (Kapp). Pure tin melts at 231.9 degC.",
        "benchmark": "melting_point",
        "scope": "material",
        "value": "241 to 354 degC"
      },
      {
        "label": "Hardness",
        "line": "Brinell hardness is 24.5 at a 500 kg load with a 10 mm ball (Kapp). Chill cast, the tensile strength is 77 MPa.",
        "benchmark": "brinell_hardness",
        "scope": "material",
        "value": "24.5 HB"
      },
      {
        "label": "Stiffness",
        "line": "The tensile elastic modulus is 52 GPa for the alloy cast at 400 degC into a 100 degC mold (Kapp).",
        "benchmark": "elastic_modulus",
        "scope": "material",
        "value": "52 GPa"
      },
      {
        "label": "Fatigue",
        "line": "Kapp gives a fatigue strength of 33 MPa at 2 x 10^7 cycles in an R.R. Moore test.",
        "benchmark": "fatigue_strength",
        "scope": "material",
        "value": "33 MPa"
      }
    ],
    "compare": "The babbitt starts to melt at 241 degC, above pure tin at 231.9 degC, and well below antimony metal at 630 degC. It is denser than antimony (7.39 against 6.68 g/cm3). The rows below compare the babbitt with those reference values.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Melting point",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Hardness",
        "benchmark": "brinell_hardness",
        "scope": "material"
      }
    ],
    "handling": [
      "Check the supplier's safety data sheet for the babbitt grade you buy; the sources read give no handling advice for the alloy.",
      "Treat dust and fume from melting or machining as the PubChem codes show for tin, antimony and lead.",
      "Keep the lining below its 241 degC solidus in service, and keep tin-rich parts above 13.2 degC if the change to grey tin matters."
    ],
    "good_for": [
      "Thin plain-bearing linings: the Kapp datasheet gives a Brinell hardness of 24.5 and a tensile strength of 77 MPa when chill cast.",
      "Engine bearings: Wikipedia says tin-based babbitt is used in combustion engines because it withstands cyclic loading."
    ],
    "watch_out": [
      "Melting range: the babbitt begins to melt at 241 degC, well below the 630 degC melting point of antimony metal.",
      "Elongation differs by source (18% on Kapp, 8.0% on Trotter) and the Trotter figure has no test conditions.",
      "Tin pest: below 13.2 degC, white tin can change to grey tin with a volume increase of about 27%; no test on the alloy was found.",
      "Antimony and lead carry serious PubChem hazard codes; the babbitt itself has no hazard data in the sources read."
    ],
    "verdict": "Tin-base babbitt is a soft, low-melting bearing alloy with a solidus of 241 degC, a Brinell hardness of 24.5 and a 77 MPa chill-cast tensile strength. Its uses are in engine bearings and as a bearing metal. Its weak points are the low melting range, the cold change of tin, and the absence of test data on corrosion, ageing and space environments. Elongation values disagree between datasheets.",
    "recipe": {
      "line": "Tin-base babbitt (ASTM B23 Grade 2) is a tin alloy with about 7.5% antimony and 3.5% copper. The nominal composition is 89% tin, 7.5% antimony and 3.5% copper, within limits of 88 to 90% tin, 7 to 8% antimony and 3 to 4% copper, with lead at or below 0.35%.",
      "parts": [
        {
          "name": "Tin",
          "symbol": "Sn",
          "role": "The base metal, 88 to 90% of the alloy by the datasheet limits.",
          "share_percent": 89
        },
        {
          "name": "Antimony",
          "symbol": "Sb",
          "role": "The main alloying addition, limit 7 to 8%.",
          "share_percent": 7.5
        },
        {
          "name": "Copper",
          "symbol": "Cu",
          "role": "A second alloying addition, limit 3 to 4%.",
          "share_percent": 3.5
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The babbitt is mostly tin, but the PubChem notifications for antimony and lead carry serious hazard codes.",
        "points": [
          {
            "label": "Antimony",
            "line": "PubChem notifications for antimony metal give H301 at 18.2%, H332 at 26.9% and H351 (suspected of causing cancer) at 31.8%, with signal word Danger."
          },
          {
            "label": "Lead",
            "line": "PubChem notifications for lead give H360 at 84.4%, which covers harm to fertility or the unborn child, and H372 at 50.5%."
          },
          {
            "label": "Tin",
            "line": "PubChem notifications for tin give H319 at 24.2% and H335 at 23.1%. A further notification gives H372."
          }
        ],
        "level": 0,
        "verdict": "Hazard codes apply to the elements"
      },
      {
        "title": "If the lining overheats",
        "lead": "The melting range of the babbitt and the cold change of tin are the two temperature limits the sources give.",
        "points": [
          {
            "label": "Melting range",
            "line": "The Kapp datasheet gives a solidus of 241 degC and a liquidus of 354 degC. The alloy starts to melt at the solidus, so its strength falls before the liquidus."
          },
          {
            "label": "Tin pest",
            "line": "Wikipedia gives 13.2 degC as the temperature at and below which white tin changes to grey tin, with a volume increase of about 27%."
          }
        ],
        "level": 1,
        "verdict": "Melts from 241 to 354 degC"
      },
      {
        "title": "Handling and storage",
        "lead": "The sources read give no handling advice for the babbitt grade itself.",
        "points": [
          {
            "label": "Safety data",
            "line": "Check the supplier's safety data sheet for the grade you buy. The PubChem codes above belong to the elements."
          }
        ],
        "level": 2,
        "verdict": "No handling advice for the alloy"
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 15,
    "unreachable": 0,
    "caveats": 5,
    "note": "Values were read by an AI assistant on 2026-10-26 from the datasheets, USGS PDFs, PubChem JSON records and Wikipedia pages named in each entry. Caveats: the babbitt values come from vendor datasheets, not the ASTM standard; the two elongation figures disagree; the PubChem antimony GHS notifications do not give test conditions; the USGS antimony shares are calculated; pewter and Sn-Pb-Sb values are composition only."
  },
  "sources": {
    "kapp-grade2": {
      "title": "Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)",
      "url": "https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/",
      "kind": "datasheet",
      "license": "vendor product page, cited not reproduced"
    },
    "trotter-grade2": {
      "title": "Nathan Trotter & Co. product data sheet, ASTM Grade 2 Babbitt Metal (SPEC NO NT Grade 2 Babbitt, Rev. 3, 2015)",
      "id": "ASTM B23-00 Alloy 2 on the sheet",
      "url": "https://nathantrotter.com/wp-content/uploads/2020/09/Grade-2-Babbitt-Data.pdf",
      "year": 2015,
      "kind": "datasheet",
      "license": "supplier document, cited not reproduced"
    },
    "wiki-babbitt": {
      "title": "Babbitt metal, Wikipedia (history, BS 3332 alloy compositions, bearing uses)",
      "url": "https://en.wikipedia.org/wiki/Babbitt_metal",
      "kind": "web",
      "license": "CC BY-SA 4.0, linked not reproduced"
    },
    "wiki-pewter": {
      "title": "Pewter, Wikipedia (composition ranges and types)",
      "url": "https://en.wikipedia.org/wiki/Pewter",
      "kind": "web",
      "license": "CC BY-SA 4.0, linked not reproduced"
    },
    "wiki-tin-pest": {
      "title": "Tin pest, Wikipedia (allotropic transformation at 13.2 degC, volume increase)",
      "url": "https://en.wikipedia.org/wiki/Tin_pest",
      "kind": "web",
      "license": "CC BY-SA 4.0, linked not reproduced"
    },
    "usgs-mcs2026-tin": {
      "title": "Mineral Commodity Summaries 2026: Tin (U.S. Geological Survey)",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-mcs2026-antimony": {
      "title": "Mineral Commodity Summaries 2026: Antimony (U.S. Geological Survey)",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-antimony.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "pubchem-antimony": {
      "title": "PubChem compound record: Antimony (CID 5354495), experimental properties and GHS classification",
      "id": "CID 5354495",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5354495/JSON",
      "year": 2026,
      "kind": "database",
      "license": "PubChem (NCBI), public domain; sections attributed to ECHA and other databases"
    },
    "pubchem-lead": {
      "title": "PubChem compound record: Lead (CID 5352425), GHS classification",
      "id": "CID 5352425",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352425/JSON",
      "year": 2026,
      "kind": "database",
      "license": "PubChem (NCBI), public domain; sections attributed to ECHA and other databases"
    },
    "pubchem-tin": {
      "title": "PubChem compound record: Tin (CID 5352426), experimental properties and GHS classification",
      "id": "CID 5352426",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON",
      "year": 2026,
      "kind": "database",
      "license": "PubChem (NCBI), public domain; sections attributed to ECHA, NITE-CMC and other databases"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/tin-antimony-babbitt/"
}