{
  "spore": "profile",
  "id": "tinned-copper",
  "spore_version": "0.2",
  "family": "copper-alloys",
  "name": "Tinned copper",
  "abbreviation": "Sn/Cu",
  "role": "electrical conductor with a solderable tin coating",
  "category": "metals",
  "type": "copper-alloys",
  "summary": "Tinned copper is copper wire, braid strand or bar with a thin tin coating, used where a copper conductor must stay solderable and resist tarnish. ASTM B33 covers tin-coated soft or annealed copper wire for electrical purposes, and the federal commercial item description A-A-59569 builds EMI shielding braid from it. Pure tin melts at 231.9 °C, conducts heat at 66.6 W/(m·K) and has a resistivity of 11.5 µΩ·cm, while the copper core is rated 58 MS/m (100 %IACS). The weak points are cold and whiskers: below 13.2 °C white tin turns to brittle grey tin, and pure tin plate can grow whiskers that short out circuits, which NASA reports caused failures of on-orbit commercial satellites.\n",
  "best_for": "Solderable, heat-conducting current paths in shields and harnesses: a 58 MS/m copper core with a tin skin, and tin-plated braid rated -65 to +150 °C",
  "weakest_at": "Cold and whiskers: tin turns brittle below 13.2 °C, and pure tin plate can grow whiskers several millimetres long that bridge closely spaced circuits",
  "identity": {
    "formula": "Copper core (Cu) with a thin tin (Sn) coating on soft or annealed wire, braid strands or bar; silver-coated copper is a separate product covered by ASTM B298",
    "cas": "7440-50-8 (copper); 7440-31-5 (tin)",
    "designations": [
      {
        "system": "ASTM",
        "code": "B33",
        "note": "tin-coated soft or annealed copper wire for electrical purposes",
        "source": "astm-b33",
        "where": "Page title of the ASTM store entry"
      }
    ],
    "source": "astm-b33",
    "where": "Title of the ASTM B33 store page (Standard Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes). CAS 7440-31-5 from the PubChem tin record; 7440-50-8 from the PubChem copper record."
  },
  "tags": {
    "environments": [],
    "stresses": [
      "vacuum-and-outgassing",
      "extreme-cold"
    ],
    "applications": [
      "electronics-and-chips"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density of tin",
      "value": 7.28,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "element",
        "temperature": "not stated on the page (NIOSH 2024 entry)"
      },
      "method": "Value printed in the density section of the PubChem record",
      "status": "ground",
      "source": "pubchem-sn",
      "where": "Chemical and Physical Properties, Density, first entry (7.28, NIOSH 2024)",
      "source_detail": {
        "title": "PubChem compound record: Tin (CID 5352426), experimental properties, GHS classification and reactivity",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON",
        "year": 2026,
        "kind": "database",
        "license": "PubChem (NCBI), public domain; some sections attributed to ECHA, HSDB and NTP (cited, not reproduced)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density of silver",
      "value": 10.49,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "metal",
        "temperature": "15 °C"
      },
      "method": "Value printed in the density section of the PubChem record",
      "status": "ground",
      "source": "pubchem-ag",
      "where": "Chemical and Physical Properties, Density, entry 10.49 @ 15 °C",
      "source_detail": {
        "title": "PubChem compound record: Silver (CID 23954), experimental properties, GHS classification and hazards summary",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23954/JSON",
        "year": 2026,
        "kind": "database",
        "license": "PubChem (NCBI), public domain (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point of tin",
      "value": 231.9,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "element",
        "pressure": "not stated"
      },
      "method": "Value printed in the melting point section of the PubChem record",
      "status": "ground",
      "source": "pubchem-sn",
      "where": "Chemical and Physical Properties, Melting Point, entry 231.9 °C",
      "source_detail": {
        "title": "PubChem compound record: Tin (CID 5352426), experimental properties, GHS classification and reactivity",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON",
        "year": 2026,
        "kind": "database",
        "license": "PubChem (NCBI), public domain; some sections attributed to ECHA, HSDB and NTP (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point of silver",
      "value": 961.78,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "metal",
        "pressure": "not stated"
      },
      "method": "Value printed in the melting point section of the PubChem record",
      "status": "ground",
      "source": "pubchem-ag",
      "where": "Chemical and Physical Properties, Melting Point, entry 961.78 °C",
      "source_detail": {
        "title": "PubChem compound record: Silver (CID 23954), experimental properties, GHS classification and hazards summary",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23954/JSON",
        "year": 2026,
        "kind": "database",
        "license": "PubChem (NCBI), public domain (cited, not reproduced)"
      }
    },
    {
      "benchmark": "allotropic_transformation_temperature",
      "label": "White (beta) to grey (alpha) tin transformation temperature",
      "value": 13.2,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "basis": "beta tin in equilibrium with alpha tin"
      },
      "method": "Value printed in the melting point section of the PubChem record (non-canonical property name)",
      "status": "ground",
      "source": "pubchem-sn",
      "where": "Chemical and Physical Properties, Melting Point, entry 'Transformation temp (beta in equilibrium with alpha) 13.2 °C'",
      "source_detail": {
        "title": "PubChem compound record: Tin (CID 5352426), experimental properties, GHS classification and reactivity",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON",
        "year": 2026,
        "kind": "database",
        "license": "PubChem (NCBI), public domain; some sections attributed to ECHA, HSDB and NTP (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity of tin",
      "value": 66.6,
      "bound": "exact",
      "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",
      "source": "webelements-sn",
      "where": "Heat and conduction, Thermal conductivity, polycrystalline value",
      "source_detail": {
        "title": "WebElements: Tin, physics properties",
        "url": "https://www.webelements.com/tin/physics.html",
        "kind": "database",
        "license": "WebElements (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity of silver",
      "value": 430,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "form": "element",
        "temperature": "not stated on the page"
      },
      "method": "Value printed on a reference-database physical properties page",
      "status": "ground",
      "source": "webelements-ag",
      "where": "Heat and conduction, Thermal conductivity",
      "source_detail": {
        "title": "WebElements: Silver, physics properties",
        "url": "https://www.webelements.com/silver/physics.html",
        "kind": "database",
        "license": "WebElements (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity of tin",
      "value": 11.5,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "form": "element",
        "temperature": "not stated on the page",
        "unit_in_source": "11.5 × 10-8 Ω m"
      },
      "method": "Printed as 11.5 × 10-8 Ω m on the WebElements page (its label reads mΩ cm, which does not match the number). Converted here to µΩ·cm, since 1 Ω m is 100 Ω cm, so the value is unchanged in magnitude: 11.5 µΩ·cm.",
      "status": "ground",
      "source": "webelements-sn",
      "where": "Electrical properties, Electrical resistivity",
      "source_detail": {
        "title": "WebElements: Tin, physics properties",
        "url": "https://www.webelements.com/tin/physics.html",
        "kind": "database",
        "license": "WebElements (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity of silver",
      "value": 1.63,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "form": "element",
        "temperature": "not stated on the page",
        "unit_in_source": "1.63 × 10-8 Ω m"
      },
      "method": "Printed as 1.63 × 10-8 Ω m on the WebElements page. Converted to µΩ·cm the same way as the tin value (1 Ω m is 100 Ω cm).",
      "status": "ground",
      "source": "webelements-ag",
      "where": "Electrical properties, Electrical resistivity",
      "source_detail": {
        "title": "WebElements: Silver, physics properties",
        "url": "https://www.webelements.com/silver/physics.html",
        "kind": "database",
        "license": "WebElements (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Young's modulus of tin",
      "value": 50,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "solid element"
      },
      "method": "Value printed on a reference-database physical properties page",
      "status": "ground",
      "source": "webelements-sn",
      "where": "Elastic properties, Young's modulus",
      "source_detail": {
        "title": "WebElements: Tin, physics properties",
        "url": "https://www.webelements.com/tin/physics.html",
        "kind": "database",
        "license": "WebElements (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of linear thermal expansion of tin",
      "value": 22,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "temperature": "not stated on the page",
        "unit_in_source": "22 × 10-6 K-1"
      },
      "method": "Value printed on a reference-database physical properties page",
      "status": "ground",
      "source": "webelements-sn",
      "where": "Heat and conduction, Coefficient of linear thermal expansion",
      "source_detail": {
        "title": "WebElements: Tin, physics properties",
        "url": "https://www.webelements.com/tin/physics.html",
        "kind": "database",
        "license": "WebElements (cited, not reproduced)"
      }
    },
    {
      "benchmark": "whisker_length",
      "label": "Tin whisker length, observed in pure tin plate",
      "value": 10,
      "bound": "lower",
      "unit": "mm",
      "scope": "material",
      "conditions": {
        "basis": "whiskers grown from pure tin plate; several millimetres are common, lengths over 10 mm are rare"
      },
      "method": "Statement in a NASA Goddard background page: lengths of several millimetres, and in rare instances over 10 mm (non-canonical property name)",
      "status": "ground",
      "source": "nasa-whisker",
      "where": "Background page, Whisker Length paragraph",
      "source_detail": {
        "title": "NASA Goddard Space Flight Center, Tin Whisker (and Other Metal Whisker) Homepage: background",
        "url": "https://nepp.nasa.gov/whisker/background/index.htm",
        "kind": "report",
        "license": "NASA public web page"
      }
    },
    {
      "benchmark": "whisker_diameter",
      "label": "Tin whisker diameter, lower end of reported range",
      "value": 100,
      "bound": "lower",
      "unit": "nm",
      "scope": "material",
      "conditions": {
        "basis": "typical diameters are a few microns; rarely less than 100 nm"
      },
      "method": "Statement in a NASA Goddard background page (non-canonical property name)",
      "status": "ground",
      "source": "nasa-whisker",
      "where": "Background page, Whisker Diameter paragraph",
      "source_detail": {
        "title": "NASA Goddard Space Flight Center, Tin Whisker (and Other Metal Whisker) Homepage: background",
        "url": "https://nepp.nasa.gov/whisker/background/index.htm",
        "kind": "report",
        "license": "NASA public web page"
      }
    },
    {
      "benchmark": "coating_thickness",
      "label": "Minimum silver coating on silver-coated copper braid",
      "value": 40,
      "bound": "lower",
      "unit": "micro-inches",
      "scope": "material",
      "conditions": {
        "product": "silver-coated copper braid under A-A-59569",
        "applies_to": "silver coating only, not tin"
      },
      "method": "Minimum thickness printed in a federal commercial item description (non-canonical property name)",
      "status": "ground",
      "source": "cid-a-a-59569",
      "where": "Section 3.2 Materials",
      "source_detail": {
        "title": "Commercial item description A-A-59569C: Braid, wire (copper, tin-coated, silver-coated, or nickel coated, tubular or flat)",
        "id": "A-A-59569C, 22 January 2009",
        "url": "https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/7161/AA59569.pdf",
        "year": 2009,
        "kind": "standard",
        "license": "U.S. government commercial item description (cited, not reproduced)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Upper temperature, tin-plated copper screening braid",
      "value": 150,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "tin-plated copper screening braid",
        "note": "the same datasheet gives +260 °C for the nickel-plated version"
      },
      "method": "Value printed in the Features list of a supplier datasheet",
      "status": "ground",
      "source": "farnell-3812260",
      "where": "Features list, bullet 'Tin Plated'",
      "source_detail": {
        "title": "Copper Screening Braid, Tin or Nickel Plated (Farnell datasheet 3812260)",
        "url": "https://www.farnell.com/datasheets/3812260.pdf",
        "kind": "datasheet",
        "license": "Supplier datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "min_service_temp",
      "label": "Lower temperature, tin-plated copper screening braid",
      "value": -65,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "tin-plated copper screening braid"
      },
      "method": "Value printed in the Features list of a supplier datasheet",
      "status": "ground",
      "source": "farnell-3812260",
      "where": "Features list, bullet 'Tin Plated'",
      "source_detail": {
        "title": "Copper Screening Braid, Tin or Nickel Plated (Farnell datasheet 3812260)",
        "url": "https://www.farnell.com/datasheets/3812260.pdf",
        "kind": "datasheet",
        "license": "Supplier datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_conductivity",
      "label": "Electrical conductivity of the copper core, soft oxygen-free grade",
      "value": 58,
      "bound": "exact",
      "unit": "MS/m",
      "scope": "material",
      "conditions": {
        "grade": "C10200 (Cu-OF)",
        "temper": "soft",
        "equivalent_in_source": "100 %IACS"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "aurubis-c10200",
      "where": "Physical properties table, Electrical cond. [MS/m] column, soft row",
      "source_detail": {
        "title": "Technical Datasheet C10200 (Cu-OF), Aurubis, version 18 08 US",
        "id": "UNS C10200; ASTM B152",
        "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer leaflet, general information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density of the copper core, C10200",
      "value": 8.9,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "C10200 (Cu-OF)"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "aurubis-c10200",
      "where": "Physical properties table, Density [g/cm3] column",
      "source_detail": {
        "title": "Technical Datasheet C10200 (Cu-OF), Aurubis, version 18 08 US",
        "id": "UNS C10200; ASTM B152",
        "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer leaflet, general information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity of the copper core, C10200 at 20 °C",
      "value": 391,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "grade": "C10200 (Cu-OF)",
        "temperature": "20 °C"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "aurubis-c10200",
      "where": "Physical properties table, Thermal cond. [W/mK] column",
      "source_detail": {
        "title": "Technical Datasheet C10200 (Cu-OF), Aurubis, version 18 08 US",
        "id": "UNS C10200; ASTM B152",
        "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer leaflet, general information only (cited, not reproduced)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Humid air, bulk tin",
      "headline": "Bulk tin is stable in air, but powdered tin oxidizes, especially with moisture.",
      "effect": "PubChem's stability entry for tin says it is stable in air, but in powder form it oxidizes, especially in the presence of moisture. The sources read give no rate for a tin coating on copper.",
      "rating": "low",
      "conditions": {
        "form": "bulk metal in air; powder with moisture"
      },
      "source": "pubchem-sn",
      "where": "Chemical and Physical Properties, Stability/Shelf Life"
    },
    {
      "environment": "Cold, below 13.2 °C",
      "headline": "Below 13.2 °C, white tin changes to brittle grey tin, which crumbles.",
      "effect": "PubChem gives 13.2 °C as the transformation point. At -40 °C tin crumbles to a grey amorphous powder (grey tin), and it changes back to white tin slowly above 20 °C. The transformation rate is not given in the sources read.",
      "rating": "moderate",
      "conditions": {
        "basis": "allotrope change in cold storage; no transformation rate in the source"
      },
      "source": "pubchem-sn",
      "where": "Color/Form (crumbles at -40 °C); Melting Point (transformation 13.2 °C)"
    },
    {
      "environment": "Air containing sulfur compounds or ozone (silver coating)",
      "headline": "Silver tarnishes in air containing sulfur or ozone, forming a dark surface film.",
      "effect": "PubChem says silver is stable in air and water but tarnishes when exposed to ozone, hydrogen sulfide or air containing sulfur. Silver sulfide, a dark-grey to black film, is named in the hazards summary. No tarnish rate or contact-resistance change was found in the sources read.",
      "rating": "moderate",
      "conditions": {
        "basis": "qualitative statement; no exposure time or rate given"
      },
      "source": "pubchem-ag",
      "where": "Chemical and Physical Properties, Stability/Shelf Life; Safety and Hazards, Hazards Summary"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem's aggregated GHS section for tin: the substance does not meet GHS hazard criteria in 72.9% (695 of 953) of company reports. The codes given are H319 (causes serious eye irritation, 24.2%) and H335 (may cause respiratory irritation, 23.1%), signal word Warning.",
        "ghs": [
          "H319",
          "H335"
        ],
        "source": "pubchem-sn",
        "where": "Safety and Hazards, GHS Classification (aggregated reports)"
      },
      {
        "text": "PubChem's aggregated GHS section for silver lists H361f (suspected of damaging fertility), H373 (may cause damage to organs through prolonged or repeated exposure), H400 (very toxic to aquatic life) and H410 (very toxic to aquatic life with long lasting effects).",
        "ghs": [
          "H361f",
          "H373",
          "H400",
          "H410"
        ],
        "source": "pubchem-ag",
        "where": "Safety and Hazards, GHS Classification, signal word Warning"
      },
      {
        "text": "PubChem's copper record, from the ECHA C&L Inventory, lists H302, H400 and H410 among the codes given by notifiers for the copper core. The record notes that classification varies with impurities and form.",
        "ghs": [
          "H302",
          "H400",
          "H410"
        ],
        "source": "pubchem-cu",
        "where": "GHS Classification, ECHA C&L Inventory"
      }
    ],
    "failure_risks": [
      {
        "mode": "Tin whisker short circuit",
        "trigger": "Pure tin plate on copper or other substrates; growth varies with plating chemistry, thickness, substrate, grain structure and storage conditions",
        "consequence": "Whiskers bridge closely spaced circuit elements. NASA reports at least three tin whisker short circuits that caused complete failure of on-orbit commercial satellites, and whisker-induced failures in medical devices, weapon systems, power plants and consumer products.",
        "severity": "high",
        "source": "nasa-whisker",
        "where": "Background page, introduction and Whisker Growth Factors"
      },
      {
        "mode": "Metal vapour arc in vacuum after a whisker short",
        "trigger": "A whisker-initiated short in a vacuum environment, as in spacecraft electronics",
        "consequence": "NASA reports metal vapour arcs in vacuum on at least three commercial satellites, which blew fuses and left the spacecraft non-operational.",
        "severity": "high",
        "source": "nasa-whisker",
        "where": "Background page, section on vacuum arcing and cited Richardson and Lasley paper"
      },
      {
        "mode": "Tin pest in cold storage",
        "trigger": "Exposure below the 13.2 °C transformation point for a long time",
        "consequence": "The tin becomes brittle grey tin, which crumbles to powder at low temperature. The sources read give no time scale for this, so tin pest may matter only for long cold storage.",
        "severity": "moderate",
        "source": "pubchem-sn",
        "where": "Color/Form and Melting Point entries"
      },
      {
        "mode": "Silver coating tarnish",
        "trigger": "Sulfur compounds or ozone in the air, with silver-coated braid",
        "consequence": "A tarnish film forms on the silver. The sources read do not report an effect on contact resistance or shielding.",
        "severity": "low",
        "source": "pubchem-ag",
        "where": "Stability/Shelf Life; Hazards Summary"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "PubChem lists strong oxidizers, hydrogen peroxide and acids as incompatible with tin, and reports that tin is combustible in fire.",
        "source": "pubchem-sn",
        "where": "Safety and Hazards, Hazardous Reactivities and Incompatibilities; Fire Hazards"
      },
      {
        "text": "Specify the coating and the temper on the order. ASTM B33 and the federal item description both require tin or silver coatings to be solderable; the commercial description requires good solderability to MIL-STD-202 method 208.",
        "source": "cid-a-a-59569",
        "where": "Section 3.5 Solderability; Section 3.2 Materials"
      }
    ],
    "mitigations": [
      {
        "text": "NASA GSFC suggests stripping pure tin plate and re-plating with a tin-lead or nickel finish, and warns that a finish laid over an existing pure tin deposit has its own risks.",
        "source": "nasa-whisker",
        "where": "Background page, mitigation paragraph"
      },
      {
        "text": "NASA GSFC experiments showed that a conformal coating (Arathane 5750) applied uniformly to a nominal 2 to 3 mils thickness helps contain whisker growth outward through the coating.",
        "source": "nasa-whisker",
        "where": "Background page, mitigation paragraph"
      }
    ]
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "EMI and RF shielding braid for wire and cable harnesses",
      "example": "Farnell's copper screening braid is sold in tin-plated or nickel-plated form to protect harnesses from electromagnetic, electrostatic and radio frequency interference, with a -65 to +150 °C range for the tin-plated version.",
      "source": "farnell-3812260",
      "where": "Features list and part number table"
    },
    {
      "application": "electronics-and-chips",
      "device": "Tin-plated copper braid for military and industrial EMI/RFI shielding",
      "example": "Glenair describes its tin-plated copper braid, part 100-001, as industry-standard EMI/RFI shielding, drawn to A-A-59569 and built from wire to ASTM B33.",
      "source": "glenair-100-001",
      "where": "Page title, description and the note 'Copper/Tin Plate I.A.W ASTM B33'"
    },
    {
      "application": "electronics-and-chips",
      "device": "Harness shielding and grounding braid",
      "example": "MBN Flexo sells tinned copper braid for shielding on harnesses and cables and for grounding, with a wire thickness of 0.005 to 0.010 inch.",
      "source": "mbn-flexo",
      "where": "Product description and specification table"
    }
  ],
  "supply": [
    {
      "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
        },
        {
          "country": "Brazil",
          "share_percent": 9.7,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: about 17000 tons of tin from old and new scrap was recycled in 2025, which the USGS says is 22% of apparent consumption.",
      "substitutes": [
        "USGS: aluminum, glass, paper, plastic or tin-free steel substitute for tin in cans and containers, and epoxy resins can replace solder."
      ],
      "source": "usgs-mcs2026-tin",
      "where": "World Mine Production and Reserves table, 2025e (world total 290000 t, tin content; shares calculated by Space Mushroom from the country values 71000, 61000, 33000 and 28000 t); Recycling; Substitutes"
    },
    {
      "subject": "Silver",
      "producers": [
        {
          "country": "Mexico",
          "share_percent": 24.2,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 13.8,
          "year": 2025
        },
        {
          "country": "China",
          "share_percent": 13.1,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "U.S. Final 2025 List of Critical Minerals (silver added in 2025, per the USGS silver summary)",
          "listed": true
        }
      ],
      "recycling": "USGS: in 2025 about 1000 tons of silver was recovered from new and old scrap, about 11% of apparent consumption.",
      "substitutes": [
        "USGS: stainless steel, tantalum and titanium can replace silver in some surgical items, and aluminum and rhodium can replace it in mirrors."
      ],
      "source": "usgs-mcs2026-silver",
      "where": "World Mine Production and Reserves table, 2025e (world total 26000 t, silver content; shares calculated by Space Mushroom from the country values 6300, 3600 and 3400 t); Recycling; Substitutes; list changes in the summary"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "ASTM B33: Standard Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes (ASTM store page)",
      "type": "standard",
      "url": "https://store.astm.org/b0033-10r14.html"
    },
    {
      "title": "Commercial item description A-A-59569C: Braid, wire (copper, tin-coated, silver-coated, or nickel coated, tubular or flat), GSA and federal agencies (2009)",
      "type": "standard",
      "url": "https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/7161/AA59569.pdf",
      "year": 2009
    },
    {
      "title": "Glenair 100-001 industry-standard tin-plated copper braid EMI/RFI shielding datasheet",
      "type": "datasheet",
      "url": "https://www.glenair.com/braided-shielding-and-sleeving/emi-rfi-tubular-expandable-braided-shielding/pdf/100-001.pdf"
    },
    {
      "title": "Farnell copper screening braid, tin or nickel plated, datasheet 3812260",
      "type": "datasheet",
      "url": "https://www.farnell.com/datasheets/3812260.pdf"
    },
    {
      "title": "MBN Flexo tinned copper braid product sheet",
      "type": "datasheet",
      "url": "https://www.cableorganizer.com/cdn/shop/files/MBN-Flexo_Tinned_Copper.pdf"
    },
    {
      "title": "PubChem compound record: Tin (JSON view, GHS, density and melting point)",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON"
    },
    {
      "title": "PubChem compound record: Silver (JSON view, GHS, density and melting point)",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23954/JSON"
    },
    {
      "title": "PubChem compound record: Copper (JSON view, atomic weight and GHS)",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23978/JSON"
    },
    {
      "title": "WebElements: Tin, physics properties",
      "type": "database",
      "url": "https://www.webelements.com/tin/physics.html"
    },
    {
      "title": "WebElements: Silver, physics properties",
      "type": "database",
      "url": "https://www.webelements.com/silver/physics.html"
    },
    {
      "title": "NASA GSFC Tin Whisker background (NEPP)",
      "type": "report",
      "url": "https://nepp.nasa.gov/whisker/background/index.htm"
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Tin",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Silver",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silver.pdf",
      "year": 2026
    },
    {
      "title": "Aurubis technical datasheet C10200 (Cu-OF), 18 08 US",
      "type": "datasheet",
      "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf"
    }
  ],
  "gaps": [
    "ASTM B546 could not be identified. The search returned only ASTM B545 (electrodeposited coatings of tin) and the ASTM store pages were not readable, so no B546 title or value is used. Confirm the intended standard.",
    "ASTM B33 text was not readable from the ASTM store, so its resistivity limits, tin coating thickness and conductor sizes are not recorded. Vendor resistance-per-length figures found in search snippets were not fetched and are not used.",
    "Tin coating thickness on tinned copper wire, braid or busbar was not found in a source read in this run.",
    "Busbar: distributor listings for tin-plated copper busbar were found (Eaton, Siemens), but the RS Components page refused access, so no busbar value or source is recorded.",
    "Tin critical-mineral status: the USGS tin summary does not state it, and the USGS 2025 list page and the EU critical raw materials list were not read for tin, so critical_lists is empty.",
    "Tin electrical conductivity in percent IACS was not read; resistivity is recorded instead, in µΩ·cm converted from the printed Ω m value.",
    "Copper-tin intermetallic growth on wire: a repository record in search results was not opened, so no growth rate is recorded. The room-temperature growth statement is therefore absent.",
    "No NASA outgassing (total mass loss), atomic oxygen erosion or radiation result for tin, silver or tin-plated copper was found in a source read in this run.",
    "Non-canonical property names used: whisker_length, whisker_diameter, allotropic_transformation_temperature and coating_thickness. Each is defined in its own property entry.",
    "Silver tarnish has no rate or contact-resistance value in the sources read.",
    "The PubChem GHS percentages for silver are not recorded because the silver record gives its codes without shares."
  ],
  "story": {
    "why": "Tinned copper keeps the high conductivity of copper and adds a tin skin that is easy to solder and resists tarnish. The copper core is rated 58 MS/m (100 %IACS) in the soft oxygen-free grade, and its thermal conductivity is 391 W/(m·K) at 20 °C. Tin adds solderability and a melting point of 231.9 °C. Shield braid built from tin-plated copper is sold for EMI and RF protection of harnesses, with a tin-plated range of -65 to +150 °C. The cost of the tin skin is the whisker risk, and in cold storage the tin can turn brittle. Silver coating is an alternative where the coating must conduct better or resist more heat.",
    "uses": [
      {
        "where": "EMI shielding",
        "line": "Farnell sells copper screening braid in tin-plated or nickel-plated form to protect harnesses from electromagnetic, electrostatic and radio frequency interference. The tin-plated version is rated -65 to +150 °C."
      },
      {
        "where": "Military and industrial braid",
        "line": "Glenair's tin-plated copper braid, part 100-001, is built to ASTM B33 and drawn to A-A-59569. Glenair calls it the industry-standard metallic EMI/RFI shield."
      },
      {
        "where": "Harness shielding and grounding",
        "line": "MBN Flexo sells tinned copper braid for shielding on harnesses and cables and for grounding, in wire thicknesses of 0.005 to 0.010 inch."
      }
    ],
    "can_do": [
      {
        "label": "Carry current",
        "line": "The soft oxygen-free copper core conducts at 58 MS/m, the 100 %IACS reference. The datasheet says this applies to the soft condition only.",
        "scope": "material",
        "value": "58 MS/m (100 %IACS)"
      },
      {
        "label": "Carry heat",
        "line": "The copper core conducts heat at 391 W/(m·K) at 20 °C. Tin conducts at 66.6 W/(m·K), and silver at 430 W/(m·K).",
        "benchmark": "thermal_conductivity",
        "scope": "material",
        "value": "391 W/(m·K)"
      },
      {
        "label": "Solder",
        "line": "Tin melts at 231.9 °C, which is the temperature range used for common solder work. The federal item description requires good solderability for tinned braid.",
        "benchmark": "melting_point",
        "scope": "material",
        "value": "231.9 °C tin melting point"
      },
      {
        "label": "Shield temperature",
        "line": "The tin-plated copper screening braid is rated -65 to +150 °C in the Farnell datasheet, and the nickel-plated version to +260 °C.",
        "benchmark": "max_service_temp",
        "scope": "material",
        "value": "-65 to +150 °C"
      }
    ],
    "compare": "Among the three coating and core metals, copper conducts heat best at 391 W/(m·K), against 66.6 W/(m·K) for tin. Silver conducts at 430 W/(m·K) but costs more and tarnishes. Tin is the lightest coating at 7.28 g/cm3 against 10.49 g/cm3 for silver and 8.9 g/cm3 for the copper core.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Melting point",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Thermal conductivity",
        "benchmark": "thermal_conductivity",
        "scope": "material"
      }
    ],
    "handling": [
      "Specify the coating and temper: the conductivity figure applies to the soft copper core, and tin is what keeps the wire solderable.",
      "Keep tin-coated parts above 13.2 °C for long storage, to avoid tin pest.",
      "Protect the wire from strong oxidizers and acids, which PubChem lists as incompatible with tin.",
      "On a whisker-prone pure tin finish, consider a tin-lead or nickel underlayer or finish, and a conformal coating, as NASA suggests."
    ],
    "good_for": [
      "Solderable current paths: 58 MS/m copper core with a tin skin, and the federal item description requires good solderability for tinned braid.",
      "EMI shielding for harnesses, with tin-plated braid rated -65 to +150 °C.",
      "Heat conduction: 391 W/(m·K) in the copper core at 20 °C."
    ],
    "watch_out": [
      "Whiskers: pure tin plate can grow whiskers several millimetres long, and at least three commercial satellites failed from whisker shorts.",
      "Cold: white tin turns to brittle grey tin below 13.2 °C.",
      "Tarnish: the silver coating tarnishes in sulfur-bearing air or ozone.",
      "No tin coating thickness, busbar figure or NASA outgassing result was found for this profile."
    ],
    "verdict": "Tinned copper is the solderable, heat-conducting option for shields and harnesses. The copper core carries the current, and the tin skin keeps it solderable. Pure tin plate can grow whiskers and turns brittle below 13.2 °C, so it suits shields and harnesses better than long-term space hardware without a whisker mitigation.",
    "recipe": {
      "line": "Tinned copper is copper (Cu, face-centred cubic, a single element) with a thin layer of tin (Sn) on its surface. The tin is deposited on the finished wire, strand or bar, and ASTM B33 governs the wire and coating. The silver-coated variant is a separate product (ASTM B298).",
      "parts": [
        {
          "name": "Copper",
          "symbol": "Cu",
          "role": "Carries the current."
        },
        {
          "name": "Tin",
          "symbol": "Sn",
          "role": "Coats the copper to keep it solderable and resistant to tarnish."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The tin coating is not classified as hazardous in most reports, but the silver coating and the copper core are classified in PubChem.",
        "points": [
          {
            "label": "Tin",
            "line": "PubChem records that tin does not meet the GHS criteria in 72.9% of company reports. The codes given are H319 (serious eye irritation) and H335 (respiratory irritation), with signal word Warning."
          },
          {
            "label": "Silver",
            "line": "PubChem's aggregated silver record lists H361f, H373, H400 and H410, including fertility and aquatic hazards."
          },
          {
            "label": "Copper",
            "line": "The copper record lists H302, H400 and H410 among the codes given by notifiers."
          }
        ],
        "level": 1,
        "verdict": "Low for tin, classified for silver"
      },
      {
        "title": "If it fails",
        "lead": "These routes come from the sources read. Two are measured in space hardware; the cold route is a material property with no time scale given.",
        "points": [
          {
            "label": "Whisker shorts",
            "line": "Pure tin plate can grow whiskers that bridge circuit spacings. NASA reports at least three commercial satellites with complete failure from whisker short circuits."
          },
          {
            "label": "Vacuum arcs",
            "line": "In vacuum, a whisker short can cause a metal vapour arc. NASA reports at least three commercial satellites with blown fuses from such arcs."
          },
          {
            "label": "Cold",
            "line": "Below 13.2 °C, white tin turns to brittle grey tin, which crumbles at low temperature."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Incompatibilities",
            "line": "PubChem lists strong oxidizers, hydrogen peroxide and acids as incompatible with tin, and reports that tin is combustible in a fire."
          },
          {
            "label": "Solderability",
            "line": "The federal commercial item description requires good solderability for tin-coated braid, tested to MIL-STD-202 method 208."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 19,
    "unreachable": 3,
    "caveats": 4,
    "note": "Written by an AI assistant on 2026-10-26 from pages read in this run. Unreachable: ASTM B33 and B298 text (store pages blocked), the RS Components busbar listing, and ASTM B546 (not identified). Caveats: tin resistivity is converted from a printed Ω m value; the braid temperatures are product limits; the silver GHS codes are aggregated; no tin coating thickness was found."
  },
  "sources": {
    "pubchem-sn": {
      "title": "PubChem compound record: Tin (CID 5352426), experimental properties, GHS classification and reactivity",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON",
      "year": 2026,
      "kind": "database",
      "license": "PubChem (NCBI), public domain; some sections attributed to ECHA, HSDB and NTP (cited, not reproduced)"
    },
    "pubchem-ag": {
      "title": "PubChem compound record: Silver (CID 23954), experimental properties, GHS classification and hazards summary",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23954/JSON",
      "year": 2026,
      "kind": "database",
      "license": "PubChem (NCBI), public domain (cited, not reproduced)"
    },
    "pubchem-cu": {
      "title": "PubChem compound record: Copper (CID 23978), atomic weight and ECHA C&L Inventory classification",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23978/JSON",
      "year": 2026,
      "kind": "database",
      "license": "PubChem (NCBI), public domain (cited, not reproduced)"
    },
    "webelements-sn": {
      "title": "WebElements: Tin, physics properties",
      "url": "https://www.webelements.com/tin/physics.html",
      "kind": "database",
      "license": "WebElements (cited, not reproduced)"
    },
    "webelements-ag": {
      "title": "WebElements: Silver, physics properties",
      "url": "https://www.webelements.com/silver/physics.html",
      "kind": "database",
      "license": "WebElements (cited, not reproduced)"
    },
    "nasa-whisker": {
      "title": "NASA Goddard Space Flight Center, Tin Whisker (and Other Metal Whisker) Homepage: background",
      "url": "https://nepp.nasa.gov/whisker/background/index.htm",
      "kind": "report",
      "license": "NASA public web page"
    },
    "astm-b33": {
      "title": "ASTM B33: Standard Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes",
      "url": "https://store.astm.org/b0033-10r14.html",
      "kind": "standard",
      "license": "ASTM store page (title read, standard text not read)"
    },
    "cid-a-a-59569": {
      "title": "Commercial item description A-A-59569C: Braid, wire (copper, tin-coated, silver-coated, or nickel coated, tubular or flat)",
      "id": "A-A-59569C, 22 January 2009",
      "url": "https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/7161/AA59569.pdf",
      "year": 2009,
      "kind": "standard",
      "license": "U.S. government commercial item description (cited, not reproduced)"
    },
    "glenair-100-001": {
      "title": "Glenair 100-001 industry-standard metallic EMI/RFI braided shielding, tin-plated copper braid",
      "url": "https://www.glenair.com/braided-shielding-and-sleeving/emi-rfi-tubular-expandable-braided-shielding/pdf/100-001.pdf",
      "kind": "datasheet",
      "license": "Manufacturer datasheet (cited, not reproduced)"
    },
    "farnell-3812260": {
      "title": "Copper Screening Braid, Tin or Nickel Plated (Farnell datasheet 3812260)",
      "url": "https://www.farnell.com/datasheets/3812260.pdf",
      "kind": "datasheet",
      "license": "Supplier datasheet (cited, not reproduced)"
    },
    "mbn-flexo": {
      "title": "MBN Flexo Tinned Copper braid product sheet",
      "url": "https://www.cableorganizer.com/cdn/shop/files/MBN-Flexo_Tinned_Copper.pdf",
      "kind": "datasheet",
      "license": "Supplier datasheet (cited, not reproduced)"
    },
    "usgs-mcs2026-tin": {
      "title": "Mineral Commodity Summaries 2026, Tin",
      "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-silver": {
      "title": "Mineral Commodity Summaries 2026, Silver",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silver.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "aurubis-c10200": {
      "title": "Technical Datasheet C10200 (Cu-OF), Aurubis, version 18 08 US",
      "id": "UNS C10200; ASTM B152",
      "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf",
      "kind": "datasheet",
      "license": "Manufacturer leaflet, general information only (cited, not reproduced)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/tinned-copper/"
}