Tin Sn

spore: profile
id: tin
spore_version: 0.2
family: low-melting-metals-and-solders
name: Tin
abbreviation: Sn
role: low-melting solder and coating metal
category: metals
type: heavy-metals
summary: |
  Tin is the element Sn (atomic number 50), a soft, low-melting metal used mainly in solder, tinplate, alloys and bearing metals. High-purity tin pellets (Sn 99.995 %) have a density of 7.28 g/cm3 at 20 °C, a melting point of 231.9 °C and a thermal conductivity of 66.8 W/(m·K) at 0 to 100 °C, according to a supplier page. Its specific heat is 213 J/(kg·K) at 25 °C. Its weak points are its softness (Mohs hardness 1.5 to 1.8) and the transformation of white (beta) tin to grey (alpha) tin below 13.2 °C, which the PubChem record gives as the transition point.
best_for: 'Low-melting solder and coatings: melting point 231.9 °C and 66.8 W/(m·K) thermal conductivity in high-purity pellets'
weakest_at: 'Hardness and cold stability: Mohs hardness 1.5 to 1.8, and a transformation to grey tin at 13.2 °C that the sources read give no rate for'
identity:
  formula: Sn (element, atomic number 50); high-purity pellet grade Sn 99.995 % (4N5)
  cas: 7440-31-5
  source: goodfellow-sn
  where: Properties table of the Goodfellow tin pellets page, CAS Number and Purity lines (Sn, 99.995 % 4N5)
  designations:
    - system: BS
      code: EN 610:1996
      note: ingot tin, grade designation 99.85
      source: lme-tin-composition
      where: Title block, BS EN 610:1996 (Grade Designation 99.85)
tags:
  applications:
    - electronics-and-chips
    - mechanisms
properties:
  - benchmark: density
    label: Density of solid tin (WebElements)
    value: 7310
    unit: kg/m3
    scope: material
    conditions:
      form: solid, polycrystalline
      temperature: not stated on the page
    method: Value printed on a reference-database physical properties page
    status: ground
    source: webelements-sn
    where: Physical properties, Density properties, Density of solid row (printed as 7310 kg m-3)
  - benchmark: density
    label: Density, white (beta) tin (PubChem)
    value: 7.265
    unit: g/cm3
    scope: material
    conditions:
      allotrope: white (beta)
      temperature: not stated in the record
    method: Value listed in the density section of the PubChem record, attributed to HSDB (reference 28)
    status: ground
    source: pubchem-sn
    where: Density section, entry 7.265 (white); 5.769 (gray)
  - benchmark: density
    label: Density, grey (alpha) tin (PubChem)
    value: 5.769
    unit: g/cm3
    scope: material
    conditions:
      allotrope: grey (alpha)
      temperature: 25 °C
    method: Value listed in the density section of the PubChem record, attributed to the PAC Chemical Database, U.S. DOE (reference 39)
    status: ground
    source: pubchem-sn
    where: Density section, entry 5.769 @25 °C
  - benchmark: density
    label: Density, high-purity tin pellets (Goodfellow)
    value: 7.28
    unit: g/cm3
    scope: material
    conditions:
      temperature: 20 °C
      form: pellets, Sn 99.995 %
    method: Value printed on the supplier product page
    status: ground
    source: goodfellow-sn
    where: Physical Properties table, Density row (7.28 at 20 °C)
  - benchmark: melting_point
    label: Melting point of tin
    value: 231.9
    unit: °C
    scope: material
    conditions:
      form: pure tin
      pressure: not stated
    method: Value listed in the melting point section of the PubChem record (HSDB and PAC entries) and printed in the Goodfellow supplier table
    status: ground
    source: pubchem-sn
    where: Melting Point section, entries 231.9 °C (HSDB, ICSC, PAC)
  - benchmark: boiling_point
    label: Boiling point of tin
    value: 2602
    unit: °C
    scope: material
    conditions:
      pressure: 760 mmHg
    method: Value listed in the boiling point section of the PubChem record, attributed to the PAC Chemical Database, U.S. DOE (reference 39)
    status: ground
    note: Other entries in the same record read 2507 °C (HSDB) and 2260 °C (ICSC); the supplier table prints 2270 °C.
    source: pubchem-sn
    where: Boiling Point section, entry 2602 °C @760 [mm Hg]
  - benchmark: allotropic_transformation_temperature
    label: Transformation temperature, beta tin in equilibrium with alpha tin
    value: 13.2
    unit: °C
    scope: material
    conditions:
      transformation: beta (white) in equilibrium with alpha (grey)
      pressure: not stated
    method: Value printed in the melting point section of the PubChem record (HSDB, reference 28)
    status: ground
    source: pubchem-sn
    where: 'Melting Point section, entry Transformation temp: (beta in equilibrium with alpha) 13.2 °C'
  - benchmark: electrical_resistivity
    label: Electrical resistivity of high-purity tin
    value: 12.6
    unit: µΩ·cm
    scope: material
    conditions:
      temperature: 20 °C
      form: pellets, Sn 99.995 %
    method: Value printed on the supplier product page
    status: ground
    source: goodfellow-sn
    where: Electrical Properties table, Electrical resistivity row (12.6 at 20 °C)
  - benchmark: thermal_conductivity
    label: Thermal conductivity of high-purity tin
    value: 66.8
    unit: W/(m·K)
    scope: material
    conditions:
      temperature: 0 to 100 °C
      form: pellets, Sn 99.995 %
    method: Value printed on the supplier product page
    status: ground
    source: goodfellow-sn
    where: Thermal Properties table, Thermal conductivity row (66.8 @0-100 °C)
  - benchmark: thermal_conductivity
    label: Thermal conductivity, polycrystalline tin (WebElements)
    value: 66.6
    unit: W/(m·K)
    scope: material
    conditions:
      form: polycrystalline
      temperature: not stated on the page
    method: Value printed on a reference-database physical properties page
    status: ground
    note: The page also prints 515 W/(m·K) parallel to the c axis and 745 W/(m·K) perpendicular to it, for single crystals.
    source: webelements-sn
    where: Heat and conduction, Thermal conductivity row (66.6 polycrystalline)
  - benchmark: specific_heat
    label: Specific heat capacity of high-purity tin
    value: 213
    unit: J/(kg·K)
    scope: material
    conditions:
      temperature: 25 °C
      form: pellets, Sn 99.995 %
    method: Value printed on the supplier product page
    status: ground
    source: goodfellow-sn
    where: Thermal Properties table, Specific heat row (213 @25 °C)
  - benchmark: cte
    label: Coefficient of thermal expansion of high-purity tin
    value: 23.5
    unit: ppm/K
    scope: material
    conditions:
      temperature: 0 to 100 °C
      unit_in_source: x10-6 K-1
      form: pellets, Sn 99.995 %
    method: Value printed on the supplier product page
    status: ground
    source: goodfellow-sn
    where: Thermal Properties table, Coefficient of thermal expansion row (23.5 @0-100 °C)
  - benchmark: cte
    label: Coefficient of linear thermal expansion (WebElements)
    value: 22
    unit: ppm/K
    scope: material
    conditions:
      unit_in_source: 10-6 K-1
      temperature: not stated on the page
    method: Value printed on a reference-database physical properties page
    status: ground
    source: webelements-sn
    where: Heat and conduction, Coefficient of linear thermal expansion row (22 × 10-6 K-1)
  - benchmark: elastic_modulus
    label: Young's modulus of tin (WebElements)
    value: 50
    unit: GPa
    scope: material
    conditions:
      form: polycrystalline
      temperature: not stated on the page
    method: Value printed on a reference-database physical properties page
    status: ground
    source: webelements-sn
    where: Elastic properties, Young's modulus row (50 GPa)
  - benchmark: elastic_modulus
    label: Tensile modulus of tin (Goodfellow)
    value: 49.9
    unit: GPa
    scope: material
    conditions:
      form: polycrystalline
      material_condition: Polycrystalline
    method: Value printed on the supplier product page
    status: ground
    source: goodfellow-sn
    where: Mechanical Properties table, Tensile modulus row (49.9 GPa)
  - benchmark: shear_modulus
    label: Shear (rigidity) modulus of tin (WebElements)
    value: 18
    unit: GPa
    scope: material
    conditions:
      form: polycrystalline
      temperature: not stated on the page
    method: Value printed on a reference-database physical properties page
    status: ground
    source: webelements-sn
    where: Elastic properties, Rigidity modulus row (18 GPa)
  - benchmark: bulk_modulus
    label: Bulk modulus of tin (Goodfellow)
    value: 58.2
    unit: GPa
    scope: material
    conditions:
      material_condition: Polycrystalline
    method: Value printed on the supplier product page
    status: ground
    source: goodfellow-sn
    where: Mechanical Properties table, Bulk modulus row (58.2 GPa)
  - benchmark: poissons_ratio
    label: Poisson's ratio of tin (Goodfellow)
    value: 0.357
    unit: '-'
    scope: material
    conditions:
      material_condition: Polycrystalline
    method: Value printed on the supplier product page
    status: ground
    source: goodfellow-sn
    where: Mechanical Properties table, Poisson's ratio row (0.357)
  - benchmark: mohs_hardness
    label: Hardness, Mohs scale
    value: 1.5
    value_high: 1.8
    bound: range
    unit: '-'
    scope: material
    conditions:
      material_condition: Polycrystalline
    method: Range printed on the supplier product page
    status: ground
    source: goodfellow-sn
    where: Mechanical Properties table, Hardness - Mohs row (1.5-1.8)
corrosion:
  - environment: Below 13.2 °C
    headline: Below 13.2 °C, white (beta) tin can change to grey (alpha) tin, the form known as tin pest.
    effect: PubChem gives 13.2 °C as the temperature at which beta tin is in equilibrium with alpha tin. The record gives no transformation rate, no volume change and no condition for the change. The Wikipedia article describes the change as spontaneous in cold conditions, but that page is not used for values here.
    rating: moderate
    conditions:
      basis: equilibrium temperature in the record, not a rate test
    source: pubchem-sn
    where: Melting Point section, transformation temperature entry
  - environment: Pure tin plating on electronic terminals
    headline: Pure tin plating can grow tin whiskers that cause electrical failures.
    effect: NASA Goddard's tin whisker pages show whiskers growing from a pure tin plated relay terminal. The page lists a 2011 symposium paper on electrical failure of an accelerator pedal position sensor caused by a tin whisker. The page gives no whisker length or growth rate.
    rating: moderate
    conditions:
      basis: NASA Goddard observations and conference papers; no rate given on the page
    source: nasa-whisker
    where: Hot Topics list and publications list on the tin whisker homepage
risks:
  hazards:
    - text: 'PubChem ECHA C&L aggregated notifications for the tin record: 72.9 % (695 of 953) of company reports say the substance 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. The record does not say which tin substance the notifications cover.'
      ghs:
        - H319
        - H335
      source: pubchem-sn
      where: GHS Classification section, European Chemicals Agency (ECHA) entries (reference 23)
    - text: 'PubChem NITE-CMC notifications for the same record: H372 causes damage to organs through prolonged or repeated exposure (specific target organ toxicity, repeated exposure, category 1, lung). Signal word Danger. Reported in two notifications, without a stated substance form.'
      ghs:
        - H372
      source: pubchem-sn
      where: GHS Classification section, NITE-CMC entries (references 35 and 36)
  failure_risks:
    - mode: Tin whisker growth on pure tin plating
      trigger: Pure tin electroplate on electronic terminals and contacts
      consequence: NASA Goddard cites an electrical failure of an accelerator pedal position sensor caused by a tin whisker. The page gives no whisker length or rate.
      severity: moderate
      source: nasa-whisker
      where: Publications list, September 2011 paper title
    - mode: Tin pest, transformation to grey tin
      trigger: Exposure to temperatures below 13.2 °C
      consequence: The PubChem record gives the transition temperature of 13.2 °C, but no rate, volume change or time to failure.
      severity: moderate
      source: pubchem-sn
      where: Melting Point section, transformation temperature entry
  side_effects: []
  handling:
    - text: PubChem records eye and respiratory irritation codes (H319, H335) and an organ-damage code for repeated exposure (H372). The sources read give no handling advice beyond these codes.
      source: pubchem-sn
      where: GHS Classification section, ECHA and NITE-CMC entries
  mitigations: []
uses:
  - application: electronics-and-chips
    device: Solder
    example: 'USGS: solder took 11 % of tin use in the United States in 2025. The USGS lists epoxy resins as a substitute for tin in solder.'
    source: usgs-mcs2026-tin
    where: Domestic Production and Use paragraph (uses percentages); Substitutes paragraph
  - application: mechanisms
    device: Bearing metals and bronze and brass alloys
    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)
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, of which about 10,000 tons came from old scrap at 1 detinning plant and 31 secondary plants. That is 22 % of apparent consumption.'
    substitutes:
      - 'USGS: aluminum, glass, paper, plastic or tin-free steel substitute for tin in cans and containers; epoxy resins for solder; aluminum alloys, alternative copper-base alloys and plastics for bronze; plastics for bearing metals.'
    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
    abundance: 'USGS 2025e reserves: Indonesia 1,400,000 t, China 1,200,000 t, Brazil 700,000 t, Australia 570,000 t, Russia 460,000 t (tin content, as printed).'
  - subject: Refined tin imports to the United States
    producers:
      - country: Peru
        share_percent: 31
        year: 2024
      - country: Bolivia
        share_percent: 27
        year: 2024
      - country: Indonesia
        share_percent: 15
        year: 2024
      - country: Brazil
        share_percent: 10
        year: 2024
    critical_lists: []
    source: usgs-mcs2026-tin
    where: 'Import Sources (2021–24) paragraph: refined tin shares; the year is the end of the 2021 to 2024 period as printed'
  - subject: Tin production in the United States
    demand: Tin has not been mined or smelted in the United States since 1993 or 1989 respectively (USGS). In 2025 a company planned a tin metal facility in Martinsville, VA, expected to be operational by late 2026 (USGS).
    critical_lists: []
    source: usgs-mcs2026-tin
    where: Domestic Production and Use paragraph; Events, Trends, and Issues paragraph
documents:
  - 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 for tin (CID 5352426): density, melting point, boiling point, GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Tin
  - title: 'WebElements: tin physical properties'
    type: database
    url: https://www.webelements.com/tin/physics.html
  - title: Goodfellow tin pellets, 99.995 % Sn, properties table
    type: datasheet
    url: https://www.goodfellow.com/eu/tin-pellets-group
  - title: NIST Atomic Weights and Isotopic Compositions for All Elements, tin
    type: database
    url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=Sn&all=all&ascii=html
  - title: 'London Metal Exchange, Special Contract Rules for Tin: BS EN 610:1996 grade 99.85'
    type: datasheet
    url: https://www.lme.com/-/media/Files/Physical-services/Brands/Chemical-composition/Chemical-composition-Tin.pdf
  - title: NASA Goddard tin whisker homepage
    type: report
    url: https://nepp.nasa.gov/whisker/
  - title: 'Wikipedia: Tin (composition, group and ore)'
    type: database
    url: https://en.wikipedia.org/wiki/Tin
gaps:
  - Tensile strength, yield strength and elongation of pure tin were not found in any fetched source, so no strength values are recorded.
  - Specific heat, thermal conductivity and CTE rest on one supplier page (Goodfellow) for the 99.995 % pellet grade, with WebElements and PubChem as second sources only where listed.
  - Electrical conductivity in %IACS was not printed on any fetched page; only resistivity is recorded.
  - 'Brinell and Vickers hardness: WebElements prints Brinell 51 MN m-2 and no Vickers value, but the Brinell row was not entered because its test conditions are not stated on the page.'
  - 'Two property names are not in spores/property-canon.yaml and are used as they are: mohs_hardness and allotropic_transformation_temperature.'
  - UNS, ASTM B339 and JIS tin designations were searched but not found in any fetched source. Only the BS EN 610:1996 grade 99.85 designation (LME sheet) is listed.
  - Critical-mineral status of tin was not found in the MCS 2026 text, and the U.S. Final 2025 critical minerals list was not opened, so the critical_lists field is empty.
  - Tin pest rate and volume change were not found in a fetched primary source; the PubChem record gives only the 13.2 °C transition temperature.
  - Atmospheric and seawater corrosion rates of tin were not found in a fetched source.
  - ECHA and NITE hazard codes come from PubChem aggregated notifications. The record does not say which tin substance each notification covers, so they are recorded as reported, not as classification of the metal.
  - Chinese, Indonesian and other mine shares are calculated from USGS 2025e values and are not printed by USGS as percentages.
  - No outgassing, atomic oxygen, radiation or UV data for tin in space were searched in this run.
  - ITRI (International Tin Research Institute) was not reached. Matmatch and Applus pages were not used as sources.
sources:
  usgs-mcs2026-tin:
    title: 'Mineral Commodity Summaries 2026: Tin (U.S. Geological Survey)'
    id: USGS MCS 2026, prepared by Chad A. Friedline
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  pubchem-sn:
    title: 'PubChem compound record: Tin (CID 5352426), including HSDB, ICSC, PAC Chemical Database and ECHA/NITE-CMC GHS entries'
    id: CID 5352426; PubChem REST pug_view JSON
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON
    kind: database
    license: PubChem (NCBI), public domain; sections attributed to HSDB, ICSC, PAC and ECHA
  webelements-sn:
    title: 'WebElements: Tin - 50 Sn, physical properties (Mark Winter, University of Sheffield)'
    url: https://www.webelements.com/tin/physics.html
    kind: database
    license: WebElements, cited not reproduced
  goodfellow-sn:
    title: Goodfellow tin pellets, 99.995 % (4N5), Sn, product properties
    id: CAS 7440-31-5; Goodfellow product page, Properties table
    url: https://www.goodfellow.com/eu/tin-pellets-group
    kind: datasheet
    license: supplier product page, cited not reproduced
  nist-sn-weights:
    title: NIST Atomic Weights and Isotopic Compositions for All Elements, tin (Sn)
    id: standard atomic weight 118.710(7)
    url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=Sn&all=all&ascii=html
    kind: database
    license: US government data
  lme-tin-composition:
    title: London Metal Exchange, Special Contract Rules for Tin, quality ingot tin, BS EN 610:1996 grade 99.85
    id: BS EN 610:1996 (Grade Designation 99.85)
    url: https://www.lme.com/-/media/Files/Physical-services/Brands/Chemical-composition/Chemical-composition-Tin.pdf
    kind: datasheet
    license: LME published contract rules, cited not reproduced
  nasa-whisker:
    title: 'NASA Goddard Space Flight Center: Tin Whisker (and Other Metal Whisker) Homepage'
    url: https://nepp.nasa.gov/whisker/
    kind: report
    license: NASA public web page
  wikipedia-tin:
    title: Tin, Wikipedia (composition, group 14 and cassiterite ore)
    url: https://en.wikipedia.org/wiki/Tin
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
license: CC-BY-4.0
updated: '2026-10-25'
review:
  status: draft
  method: assistant
  checked_values: 19
  unreachable: 2
  caveats: 6
  note: 'Values were read by an AI assistant on 2026-10-25 from the pages and PDF named in each entry (USGS text extracted from the PDF; PubChem values from its JSON record). Unreachable: NIOSH pocket guide (access denied), Matmatch EN 610 grade page (download failed). Caveats: PubChem density and melting values carry no test conditions; the GHS notifications do not say which tin substance they cover; the Goodfellow pellet values are for 99.995 % Sn; the USGS mine shares are calculated; no UNS code was found.'
story:
  risk_groups:
    - title: For people
      lead: The GHS codes in PubChem come from company notifications, and the record does not say which tin substance they cover.
      level: 1
      verdict: Mixed notifications
      points:
        - label: Tin as recorded in PubChem
          line: Of 953 company reports to the European chemicals agency, 695 say tin does not meet GHS criteria. Where codes were given, H319 (eye irritation) and H335 (respiratory irritation) appear, with signal word Warning. A Japanese NITE notification gives H372 (organ damage from repeated exposure) with signal word Danger.
    - title: If it fails
      lead: The failure routes in these sources are whiskers grown from pure tin plating and the cold transformation of white tin.
      points:
        - label: Tin whiskers
          line: NASA Goddard shows whiskers growing from pure tin plating and cites an electrical failure of a sensor caused by a whisker. The page gives no growth rate.
        - label: Tin pest
          line: PubChem gives 13.2 °C as the temperature at which white tin and grey tin are in equilibrium. No rate or volume change is given in the record.
    - title: Handling and storage
      points:
        - label: Cold storage
          line: Keep tin above 13.2 °C if the transformation to grey tin matters for the part. The record gives the temperature, not a rate.
        - label: Hazard codes
          line: PubChem lists eye and respiratory irritation codes. The sources read give no further handling advice.
  why: Tin is a soft, low-melting metal. High-purity tin pellets melt at 231.9 °C, have a density of 7.28 g/cm3 at 20 °C, and conduct heat at 66.8 W/(m·K) at 0 to 100 °C. It is used in solder and tinplate, and in bearing metals with bronze and brass. The USGS puts solder at 11 % and babbitt, brass, bronze and tinning together at 7 % of U.S. tin use in 2025. Its weak points are its softness, with a Mohs hardness of 1.5 to 1.8, and the change to grey tin at 13.2 °C.
  uses:
    - where: Solder
      line: Solder took 11 % of U.S. tin use in 2025 (USGS).
    - where: Bearing metals and bronze
      line: Babbitt, brass and bronze, and tinning together took 7 % of U.S. tin use in 2025 (USGS).
  can_do:
    - label: Melt low
      value: 231.9 °C melting point
      benchmark: melting_point
      line: Tin melts at 231.9 °C, printed in the PubChem record and in the Goodfellow table.
    - label: Carry heat
      value: 66.8 W/(m·K)
      benchmark: thermal_conductivity
      line: High-purity tin has a thermal conductivity of 66.8 W/(m·K) at 0 to 100 °C (Goodfellow). WebElements gives 66.6 W/(m·K) for polycrystalline tin.
    - label: Weight
      value: 7.28 g/cm3
      benchmark: density
      line: Density is 7.28 g/cm3 at 20 °C (Goodfellow). The PubChem record gives 7.265 g/cm3 for white tin and 5.769 g/cm3 for grey tin at 25 °C.
    - label: Stiffness
      value: 49.9 GPa tensile modulus
      benchmark: elastic_modulus
      line: Polycrystalline tin has a tensile modulus of 49.9 GPa (Goodfellow) and a Young's modulus of 50 GPa (WebElements).
  compare: The sources read for tin are for different grades and conditions, and the other profiles of this site use different grades, so read the table rows as examples, not a ranking.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Thermal conductivity
      benchmark: thermal_conductivity
    - label: Thermal expansion
      benchmark: cte
  handling:
    - Specify the grade, because the pellet values (Sn 99.995 %) and the mixed-grade values differ.
    - Keep the part above 13.2 °C if the transformation to grey tin matters.
    - Follow the PubChem hazard codes (H319, H335, H372) when handling dust or fume.
  good_for:
    - 'Solder and coatings: low melting point (231.9 °C) and good heat conduction (66.8 W/(m·K)).'
    - 'Recyclability: about 22 % of U.S. apparent tin consumption came from recycled scrap in 2025 (USGS).'
  watch_out:
    - 'Softness: Mohs hardness 1.5 to 1.8.'
    - 'Cold change: white tin changes to grey tin at 13.2 °C (PubChem).'
    - 'Whiskers: pure tin plating can grow tin whiskers that cause electrical failures (NASA).'
    - 'Supply: China, Indonesia and Peru are the largest mine producers of tin in 2025e (USGS), see the supply section for the calculated shares.'
    - No tensile strength, outgassing or atomic oxygen data were found for tin in this run.
  verdict: Tin is a soft, low-melting metal, with a melting point of 231.9 °C and thermal conductivity of 66.8 W/(m·K) in high-purity pellets. It is used in solder, tinplate and bearing metals. Its weak points are its softness, its change to grey tin below 13.2 °C, and whisker growth from pure plating. The profile lacks tensile, outgassing and space-exposure data.
  recipe:
    line: Tin is a single element (Sn, atomic number 50, group 14). Wikipedia says it is obtained chiefly from the mineral cassiterite, which contains stannic oxide SnO2. The USGS summary gives the production statistics but not the smelting route, so the process is stated only at this level.
    parts:
      - name: Tin
        symbol: Sn
        atoms: 1
        atomic_weight: 118.71
        role: The whole material. NIST gives the standard atomic weight as 118.710(7).