{
  "spore": "profile",
  "id": "gilding-metal",
  "spore_version": "0.2",
  "family": "copper-alloys",
  "name": "Gilding metal 95/5",
  "abbreviation": "C21000",
  "role": "cold-working copper-zinc alloy, high copper",
  "category": "metals",
  "type": "copper-alloys",
  "summary": "Gilding metal 95/5 (UNS C21000, CuZn5, EN CW500L) is a copper-zinc alloy with 95 % copper and 5 % zinc. Wieland calls it the historic penny alloy and says it is the usual choice for deep-drawn bullet jackets and coined products. Its density is 8.86 g/cm3, its thermal conductivity is 234 W/(m·K) at room temperature and its conductivity is 56 %IACS. Annealed tensile strength runs from 235 to 275 MPa (Wieland) and the spring temper H08 from 415 to 470 MPa (Wieland). The CuZn10 grade (C22000, commercial bronze, the tombac range) is covered as a second grade in this file: Aurubis gives 248 to 290 MPa annealed and 476 to 531 MPa in H08. CuZn15 (C23000) is named in the Wieland table, but no property of it was read.\n",
  "best_for": "Deep-drawn and coined parts such as bullet jackets, coins, connectors and fasteners, where copper is too soft or too costly and moderate conductivity with extra strength is enough (Wieland)",
  "weakest_at": "Season cracking in ammonia or amine atmospheres when cold-forming stress is left in the part, and poor machinability (Fisk index 1, poor)",
  "identity": {
    "formula": "CuZn5, UNS C21000: copper 94.0 to 96.0 wt%, lead 0.05 wt% maximum, iron 0.05 wt% maximum, zinc remainder",
    "designations": [
      {
        "system": "UNS",
        "code": "C21000",
        "source": "wieland-m05",
        "where": "Datasheet heading: CuZn5 | C21000 | CW500L"
      },
      {
        "system": "EN name",
        "code": "CW500L",
        "source": "wieland-m05",
        "where": "Datasheet heading: CuZn5 | C21000 | CW500L"
      },
      {
        "system": "EN name",
        "code": "CuZn5",
        "source": "wieland-m05",
        "where": "Datasheet heading: CuZn5 | C21000 | CW500L"
      },
      {
        "system": "JIS",
        "code": "C2100",
        "source": "wieland-brass-table",
        "where": "Brass alloys table, row M05, JIS-No. column"
      },
      {
        "system": "ASTM",
        "code": "B36",
        "note": "plate, sheet, strip and rolled bar",
        "source": "fisk-c21000-pdf",
        "where": "Specifications box: ASTM B36"
      },
      {
        "system": "ASTM",
        "code": "B134",
        "note": "wire",
        "source": "fisk-c21000-pdf",
        "where": "Specifications box: ASTM B134"
      },
      {
        "system": "Trade name",
        "code": "Gilding Metal",
        "source": "wieland-m05",
        "where": "Opening paragraph: Known as Gilding Metal, C21000"
      }
    ],
    "source": "aviva-c21000",
    "where": "Chemical Composition table on the Aviva C21000 page (Cu 94.0 to 96.0, Pb 0.05 max, Fe 0.05 max, Zn rem); the same limits appear on the Fisk C21000 PDF, and the nominal Cu 95 and Zn 5 appear on the Wieland M05 datasheet."
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "electronics-and-chips",
      "mechanisms"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, C21000 (Wieland)",
      "value": 8.86,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temperature": "room temperature (reference value)",
        "unit_in_source": "0.320 lb/in3 (Wieland US column)"
      },
      "method": "Value printed in the metric column of a manufacturer's reference table; the Aviva page prints specific gravity 8.86 for the same alloy",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Physical properties table, Density row, metric column",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, C21000 (Wieland)",
      "value": 234,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temperature": "room temperature (reference value)",
        "unit_in_source": "135 Btu.ft/(ft2.h.°F) (Wieland US column)"
      },
      "method": "Value printed in the metric column of the Wieland physical properties table; Fisk prints the same 234 W/m K at 20 °C on its product page",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Physical properties table, Thermal conductivity row, metric column",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_conductivity",
      "label": "Electrical conductivity, annealed C21000 (Wieland)",
      "value": 56,
      "bound": "exact",
      "unit": "%IACS",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temperature": "room temperature (reference value)",
        "unit_in_source": "33 MS/m (Wieland metric column)"
      },
      "method": "Value printed in the %IACS column of the Wieland table; Fisk prints the same 56 % IACS at 68 °F",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Physical properties table, Electrical conductivity row, %IACS column",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, annealed C21000 (Fisk)",
      "value": 3.08,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Fisk Gilding 95 %)",
        "temper": "annealed",
        "temperature": "20 °C",
        "unit_in_source": "18.5 Ω·cir-mil/ft at 68 °F (Fisk English column)"
      },
      "method": "Value printed in the metric column of the Fisk physical properties table on the product page",
      "status": "ground",
      "source": "fisk-c21000",
      "where": "Physical Properties table, Electrical Resistivity (Annealed) row, metric column",
      "source_detail": {
        "title": "Fisk Alloy, C21000 Gilding, 95% product page: composition limits, physical properties (metric and US), round wire temper table, alloy description and listed uses",
        "url": "https://fiskalloy.com/product/c21000/",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Solidus, C21000 (Fisk)",
      "value": 954,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Fisk Gilding 95 %)",
        "unit_in_source": "1,750 °F (English column)",
        "pressure": "not stated"
      },
      "method": "Value printed in the metric column of the Fisk physical properties table; the Aviva page prints a solidus of 1920 °F, which conflicts and is not used (see gaps)",
      "status": "ground",
      "source": "fisk-c21000",
      "where": "Physical Properties table, Melting Point (Solidus) row, metric column",
      "source_detail": {
        "title": "Fisk Alloy, C21000 Gilding, 95% product page: composition limits, physical properties (metric and US), round wire temper table, alloy description and listed uses",
        "url": "https://fiskalloy.com/product/c21000/",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Liquidus, C21000 (Fisk)",
      "value": 1049,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Fisk Gilding 95 %)",
        "unit_in_source": "1,920 °F (English column)",
        "pressure": "not stated"
      },
      "method": "Value printed in the metric column of the Fisk physical properties table on the product page",
      "status": "ground",
      "source": "fisk-c21000",
      "where": "Physical Properties table, Melting Point (Liquidus) row, metric column",
      "source_detail": {
        "title": "Fisk Alloy, C21000 Gilding, 95% product page: composition limits, physical properties (metric and US), round wire temper table, alloy description and listed uses",
        "url": "https://fiskalloy.com/product/c21000/",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, C21000 (Wieland)",
      "value": 18,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temperature": "0 to 300 °C",
        "unit_in_source": "10.0 10-6/°F (Wieland US column)"
      },
      "method": "Printed as 18.0 10-6/K in the Wieland reference table, between 0 and 300 °C; the number is copied without conversion because 10-6/K equals ppm/K",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Physical properties table, Coefficient of thermal expansion row, metric column, footnote for 0 to 300 °C",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, C21000 (Wieland)",
      "value": 117,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temperature": "room temperature (reference value)",
        "unit_in_source": "17,000 ksi (Wieland US column)"
      },
      "method": "Value printed in the metric column of the Wieland reference table",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Physical properties table, Modulus of elasticity row, metric column",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat, C21000 (Wieland)",
      "value": 0.38,
      "bound": "exact",
      "unit": "J/(g·K)",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temperature": "room temperature (reference value)",
        "unit_in_source": "0.091 Btu/(lb.°F) (Wieland US column)"
      },
      "method": "Value printed in the metric column of the Wieland reference table, in J/(g.K); not converted",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Physical properties table, Specific heat row, metric column",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "poissons_ratio",
      "label": "Poisson's ratio, C21000 (Wieland)",
      "value": 0.34,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temperature": "room temperature (reference value)"
      },
      "method": "Printed without a unit in the Wieland reference table",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Physical properties table, Poisson's ratio row",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, annealed C21000, sheet and strip (Wieland)",
      "value": 235,
      "value_high": 275,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temper": "annealed (Wieland), ASTM B36 temper",
        "product_form": "sheet, strip and rolled bar",
        "unit_in_source": "34-40 ksi (Wieland US column)"
      },
      "method": "Range printed in the mechanical properties table by temper, metric column; the table note says the values are to ASTM B36, and the bracketed yield and elongation figures are for information only and are not used",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Mechanical properties table, Annealed row, Tensile strength Rm column (MPa)",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, half-hard H02, sheet and strip (Wieland)",
      "value": 290,
      "value_high": 360,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temper": "H02, half hard",
        "product_form": "sheet, strip and rolled bar",
        "unit_in_source": "42-52 ksi (Wieland US column)"
      },
      "method": "Range printed in the mechanical properties table by temper, metric column, marked as to ASTM B36",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Mechanical properties table, H02 row, Tensile strength Rm column (MPa)",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, hard H04, sheet and strip (Wieland)",
      "value": 345,
      "value_high": 405,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temper": "H04, hard",
        "product_form": "sheet, strip and rolled bar",
        "unit_in_source": "50-59 ksi (Wieland US column)"
      },
      "method": "Range printed in the mechanical properties table by temper, metric column, marked as to ASTM B36",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Mechanical properties table, H04 row, Tensile strength Rm column (MPa)",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, spring H08, sheet and strip (Wieland)",
      "value": 415,
      "value_high": 470,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (CuZn5)",
        "temper": "H08, spring",
        "product_form": "sheet, strip and rolled bar",
        "unit_in_source": "60-68 ksi (Wieland US column)"
      },
      "method": "Range printed in the mechanical properties table by temper, metric column, marked as to ASTM B36",
      "status": "ground",
      "source": "wieland-m05",
      "where": "Mechanical properties table, H08 row, Tensile strength Rm column (MPa)",
      "source_detail": {
        "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
        "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, half-hard H02 round wire (minimum)",
      "value": 330,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Fisk Gilding 95 %)",
        "temper": "H02, 1/2 hard",
        "product_form": "round wire, mill limits 0.0254 to 3.264 mm",
        "measure": "minimum",
        "unit_in_source": "49.0 ksi (English column)"
      },
      "method": "Minimum value printed in the Fisk round wire temper table, metric column; wire, so not comparable with the flat-product rows",
      "status": "ground",
      "source": "fisk-c21000",
      "where": "Round Wire temper table, metric block, H02 row, Tensile Strength Min (MPa)",
      "source_detail": {
        "title": "Fisk Alloy, C21000 Gilding, 95% product page: composition limits, physical properties (metric and US), round wire temper table, alloy description and listed uses",
        "url": "https://fiskalloy.com/product/c21000/",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, hard H04 round wire (minimum)",
      "value": 420,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Fisk Gilding 95 %)",
        "temper": "H04, hard",
        "product_form": "round wire, mill limits 0.0254 to 3.264 mm",
        "measure": "minimum",
        "unit_in_source": "61.0 ksi (English column)"
      },
      "method": "Minimum value printed in the Fisk round wire temper table, metric column; wire, not sheet",
      "status": "ground",
      "source": "fisk-c21000",
      "where": "Round Wire temper table, metric block, H04 row, Tensile Strength Min (MPa)",
      "source_detail": {
        "title": "Fisk Alloy, C21000 Gilding, 95% product page: composition limits, physical properties (metric and US), round wire temper table, alloy description and listed uses",
        "url": "https://fiskalloy.com/product/c21000/",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, spring H08 round wire (minimum)",
      "value": 490,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Fisk Gilding 95 %)",
        "temper": "H08, spring",
        "product_form": "round wire, mill limits 0.0254 to 3.264 mm",
        "measure": "minimum",
        "unit_in_source": "72.0 ksi (English column)"
      },
      "method": "Minimum value printed in the Fisk round wire temper table, metric column; the table gives no maximum for this temper",
      "status": "ground",
      "source": "fisk-c21000",
      "where": "Round Wire temper table, metric block, H08 row, Tensile Strength Min (MPa)",
      "source_detail": {
        "title": "Fisk Alloy, C21000 Gilding, 95% product page: composition limits, physical properties (metric and US), round wire temper table, alloy description and listed uses",
        "url": "https://fiskalloy.com/product/c21000/",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, annealed OS050 (Aviva)",
      "value": 45,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Aviva)",
        "temper": "OS050, nominal grain size 0.050 mm, annealed",
        "gauge_length": "0.04 in section",
        "basis": "typical value, 68 °F"
      },
      "method": "Typical value (Typ) printed in the Aviva mechanical properties by temper table; the page is US units only and no metric column exists",
      "status": "ground",
      "source": "aviva-c21000",
      "where": "Mechanical Properties by Temper table, OS050 row, Elong. (%) column",
      "source_detail": {
        "title": "Aviva Metals, C21000 Gilding Brass page: chemical composition, physical properties (US units), mechanical properties by temper (typical), fabrication ratings, typical uses, specifications",
        "url": "https://www.avivametals.com/collections/copper-alloys/beryllium-copper/c21000-gilding-brass-1",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, half-hard H02 (Aviva)",
      "value": 12,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Aviva)",
        "temper": "H02, half hard",
        "gauge_length": "0.04 in section",
        "basis": "typical value, 68 °F"
      },
      "method": "Typical value (Typ) printed in the Aviva mechanical properties by temper table",
      "status": "ground",
      "source": "aviva-c21000",
      "where": "Mechanical Properties by Temper table, 1/2 Hard (H02) row, Elong. (%) column",
      "source_detail": {
        "title": "Aviva Metals, C21000 Gilding Brass page: chemical composition, physical properties (US units), mechanical properties by temper (typical), fabrication ratings, typical uses, specifications",
        "url": "https://www.avivametals.com/collections/copper-alloys/beryllium-copper/c21000-gilding-brass-1",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, hard H04 (Aviva)",
      "value": 5,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Aviva)",
        "temper": "H04, hard",
        "gauge_length": "0.04 in section",
        "basis": "typical value, 68 °F"
      },
      "method": "Typical value (Typ) printed in the Aviva mechanical properties by temper table",
      "status": "ground",
      "source": "aviva-c21000",
      "where": "Mechanical Properties by Temper table, Hard (H04) row, Elong. (%) column",
      "source_detail": {
        "title": "Aviva Metals, C21000 Gilding Brass page: chemical composition, physical properties (US units), mechanical properties by temper (typical), fabrication ratings, typical uses, specifications",
        "url": "https://www.avivametals.com/collections/copper-alloys/beryllium-copper/c21000-gilding-brass-1",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, spring H08 (Aviva)",
      "value": 4,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "C21000 (Aviva)",
        "temper": "H08, spring",
        "gauge_length": "0.04 in section",
        "basis": "typical value, 68 °F"
      },
      "method": "Typical value (Typ) printed in the Aviva mechanical properties by temper table",
      "status": "ground",
      "source": "aviva-c21000",
      "where": "Mechanical Properties by Temper table, Spring (H08) row, Elong. (%) column",
      "source_detail": {
        "title": "Aviva Metals, C21000 Gilding Brass page: chemical composition, physical properties (US units), mechanical properties by temper (typical), fabrication ratings, typical uses, specifications",
        "url": "https://www.avivametals.com/collections/copper-alloys/beryllium-copper/c21000-gilding-brass-1",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "machinability_rating",
      "label": "Machinability rating, C21000 (Aviva)",
      "value": 20,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "C21000",
        "temper": "not stated",
        "basis": "relative index; the base (100 = reference alloy) is not printed on this page"
      },
      "method": "Index printed in the Aviva fabrication table; a relative rating, not a measured property. Fisk rates the same alloy 1 (poor) on its own scale, and the two scales are not compared",
      "status": "ground",
      "source": "aviva-c21000",
      "where": "Fabrication properties, Machinability Rating row",
      "source_detail": {
        "title": "Aviva Metals, C21000 Gilding Brass page: chemical composition, physical properties (US units), mechanical properties by temper (typical), fabrication ratings, typical uses, specifications",
        "url": "https://www.avivametals.com/collections/copper-alloys/beryllium-copper/c21000-gilding-brass-1",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, C22000 CuZn10 (Aurubis)",
      "value": 8.8,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "temperature": "20 °C",
        "unit_in_source": "0.318 lb/in3 (Aurubis US column)"
      },
      "method": "Value printed in the metric column of the Aurubis technical datasheet; Wieland's M10 datasheet prints 8.80 g/cm3, which is consistent",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Physical properties table, Density row, metric column",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, C22000 CuZn10 (Aurubis)",
      "value": 1043,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "unit_in_source": "1910 °F (Aurubis US column)",
        "pressure": "not stated"
      },
      "method": "Single melting point value printed in the Aurubis physical properties table; no solidus and liquidus pair is printed",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Physical properties table, Melting point row, metric column",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity at 20 °C, C22000 CuZn10 (Aurubis)",
      "value": 189,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "temperature": "20 °C",
        "unit_in_source": "109 Btu/(ft h °F) (Aurubis US column)"
      },
      "method": "Value printed in the metric column of the Aurubis physical properties table; Wieland M10 prints 189 W/(m.K) for the same grade",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Physical properties table, Thermal conductivity at 20 °C row, metric column",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_conductivity",
      "label": "Electrical conductivity, soft C22000 CuZn10 (Aurubis)",
      "value": 44,
      "bound": "exact",
      "unit": "%IACS",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "temper": "soft (the conductivity applies to the soft condition only)",
        "temperature": "20 °C"
      },
      "method": "Value printed in the %IACS column of the Aurubis physical properties table; the same row gives 26 MS/m, which Wieland prints as 25 MS/m, so the %IACS value is used",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Physical properties table, Electrical conductivity row, %IACS column",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, C22000 CuZn10 (Aurubis)",
      "value": 18.4,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "temperature": "20 °C",
        "unit_in_source": "10.2 10-6/°F (Aurubis US column)"
      },
      "method": "Printed as 18.4 10-6/K in the metric column of the Aurubis table; the same column header also gives the 20 °C condition",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Physical properties table, Coef. of therm exp. row, metric column",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, C22000 CuZn10 (Aurubis)",
      "value": 117,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "temperature": "20 °C",
        "unit_in_source": "17 x 1000 ksi (Aurubis US column)"
      },
      "method": "Value printed in the GPa column of the Aurubis physical properties table",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Physical properties table, Mod. of elasticity row, GPa column",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, soft C22000 CuZn10 sheet (Aurubis)",
      "value": 248,
      "value_high": 290,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "temper": "soft",
        "product_form": "sheet and strip (Aurubis leaflet, no form stated for the row)",
        "unit_in_source": "36-42 ksi (Aurubis US column)"
      },
      "method": "Range printed in the Aurubis mechanical properties table, metric column; the table note says other tempers are available on request, and no minimum is printed",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Mechanical properties table, Soft row, Tensile strength Rm column (MPa)",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, H04 C22000 CuZn10 sheet (Aurubis)",
      "value": 393,
      "value_high": 455,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "temper": "H04",
        "product_form": "sheet and strip (Aurubis leaflet, no form stated for the row)",
        "unit_in_source": "57-66 ksi (Aurubis US column)"
      },
      "method": "Range printed in the Aurubis mechanical properties table, metric column",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Mechanical properties table, H04 row, Tensile strength Rm column (MPa)",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, H08 C22000 CuZn10 sheet (Aurubis)",
      "value": 476,
      "value_high": 531,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "temper": "H08",
        "product_form": "sheet and strip (Aurubis leaflet, no form stated for the row)",
        "unit_in_source": "69-77 ksi (Aurubis US column)"
      },
      "method": "Range printed in the Aurubis mechanical properties table, metric column",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Mechanical properties table, H08 row, Tensile strength Rm column (MPa)",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, soft C22000 CuZn10 (Aurubis)",
      "value": 47,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "C22000 (CuZn10, tombac range)",
        "temper": "soft",
        "gauge_length": "2 in"
      },
      "method": "Value printed in the nominal elongation column of the Aurubis mechanical properties table (2 in gauge)",
      "status": "ground",
      "source": "aurubis-c22000",
      "where": "Mechanical properties table, Soft row, Elongation 2 in column",
      "source_detail": {
        "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
        "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Ammonia or amine atmospheres with tensile stress (season cracking)",
      "headline": "Brass season cracking is the classic failure of cold-formed copper-zinc alloys in ammonia. No rating for gilding metal was printed in the sources read.",
      "effect": "The Hendrix Group says stress corrosion cracking needs both a high tensile stress and a specific corrosive environment, which for brasses is usually ammonia or amines, and that drawing and bending leave internal stresses that cause cracking unless they are removed by stress relief. The same article recommends low-zinc alloys over high-zinc alloys where service allows, and says the higher the copper content, the better the resistance. C21000 has 5 % zinc, so it sits at the low-zinc, high-copper end. No threshold stress or time to crack for C21000 is printed in the sources.",
      "rating": "unknown",
      "conditions": {
        "basis": "qualitative description for brasses in general; no rating or threshold for C21000 is printed in the sources",
        "test_example": "Accelerated test cited by the Hendrix Group: air containing 10 % ammonia and 3.7 % water vapour at 35 °C (a test condition, not a service limit)"
      },
      "source": "hgh-scc",
      "where": "Sections on the environment, cold working and copper content; the Hendrix test paragraph"
    },
    {
      "environment": "Outdoor exposure and dezincification (CuZn10, tombac range)",
      "headline": "Aurubis says the 90/10 alloy has excellent resistance to stress-corrosion cracking and to dezincification.",
      "effect": "The Aurubis datasheet for C22000 says its excellent resistance to stress-corrosion cracking and dezincification makes it suitable as an engineering alloy, widely used for ammunition components and for applications requiring outdoor exposure. No dezincification depth or test result is printed, and the claim is a supplier statement, not a measured rate.",
      "rating": "low",
      "conditions": {
        "basis": "supplier statement for C22000, not measured data; no dezincification test condition is printed"
      },
      "source": "aurubis-c22000",
      "where": "Description paragraph, first sentences"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Lead: C21000 contains 0.05 wt% lead at most (Aviva and Fisk limits). The ATSDR ToxFAQ says lead can affect almost every organ and system in the body and that HHS considers lead and lead compounds reasonably anticipated to be human carcinogens. No GHS code for the alloy was read.",
        "ghs": [],
        "source": "atsdr-lead",
        "where": "ToxFAQs sections on health effects and cancer"
      }
    ],
    "failure_risks": [
      {
        "mode": "Season cracking in ammonia",
        "trigger": "Tensile stress from cold forming (drawing, pressing, spinning, bending) together with an ammonia or amine atmosphere",
        "consequence": "Cracking, which the Hendrix Group says is liable to occur in drawn tube that has not been stress-relieved",
        "severity": "moderate",
        "source": "hgh-scc",
        "where": "Cold working and stress relief sections"
      },
      {
        "mode": "Poor machinability",
        "trigger": "Machining or tool cutting of the alloy in a fabrication process",
        "consequence": "Fisk rates machinability 1 (poor) on its fabrication index, and Aviva gives a machinability rating of 20 on its relative scale, so the alloy is a poor choice where machining is the main process",
        "severity": "low",
        "source": "fisk-c21000",
        "where": "Fabrication Index table, Machinability row"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Specify the temper: Wieland gives annealed sheet 235 to 275 MPa tensile, H02 290 to 360 MPa, H04 345 to 405 MPa and H08 415 to 470 MPa.",
        "source": "wieland-m05",
        "where": "Mechanical properties table"
      },
      {
        "text": "Anneal between 427 and 788 °C to soften the alloy; Fisk gives the annealing range as 800 to 1450 °F, which is 427 to 788 °C in the metric column.",
        "source": "fisk-c21000",
        "where": "Physical Properties table, Annealing Range rows"
      },
      {
        "text": "Stress-relieve after cold forming. The Hendrix Group gives a general range of one half to one hour at 250 to 300 °C for brasses, and says the optimum depends on the alloy.",
        "source": "hgh-scc",
        "where": "Stress relief paragraph"
      },
      {
        "text": "Keep parts out of ammonia and amine atmospheres in service.",
        "source": "hgh-scc",
        "where": "Environment section"
      },
      {
        "text": "Machining chips and dust from the alloy contain lead at up to 0.05 %; the ATSDR advice to avoid lead exposure applies (this is our inference from the advice, not a statement in the source).",
        "source": "atsdr-lead",
        "where": "How can I protect my family from lead exposure"
      }
    ],
    "mitigations": [
      {
        "text": "The Hendrix Group says the higher the copper content, the better the resistance to stress corrosion cracking, and recommends low-zinc alloys over high-zinc alloys where service and manufacture allow. C21000 is 95 % copper.",
        "source": "hgh-scc",
        "where": "Effect of composition section"
      },
      {
        "text": "Choose a stress-relieved or annealed temper for parts that are formed and then exposed to ammonia or amines.",
        "source": "hgh-scc",
        "where": "Cold working and stress relief sections (this is our summary of the advice, not a quote)"
      }
    ]
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Electrical connectors and AC motor rotor bars",
      "example": "Aviva lists connectors under electrical uses, citing electrical and thermal conductivity, corrosion resistance and formability, and lists rotor bars for AC motors citing brazability and electrical resistivity. Wieland says the alloy is a valuable option for electrical applications where performance requirements preclude standard copper. These are terrestrial uses; no source names a space system.",
      "source": "aviva-c21000",
      "where": "Typical Uses list, Electrical row (Connectors and Rotor Bars, AC Motors); Wieland M05 opening paragraph"
    },
    {
      "application": "mechanisms",
      "device": "Fasteners and connector components",
      "example": "Fisk lists connector components and fasteners as the uses of C21000, and Aviva lists fasteners, citing appearance, corrosion resistance and formability. These are terrestrial uses; no source names a space system.",
      "source": "fisk-c21000",
      "where": "Alloy description paragraph (Listed uses); Aviva Typical Uses list, Fasteners row"
    }
  ],
  "supply": [],
  "media": [],
  "documents": [
    {
      "title": "Wieland: M05 CuZn5 | C21000 | CW500L rolled products datasheet (composition, physical and mechanical properties by temper)",
      "type": "datasheet",
      "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf"
    },
    {
      "title": "Wieland: brass alloys table, row M05 (CuZn5, CW500L, C21000, C2100) and row M10 (CuZn10, CW501L, C22000, C2200)",
      "type": "datasheet",
      "url": "https://www.wieland.com/products/brass-alloys"
    },
    {
      "title": "Fisk Alloy: C21000 Gilding, 95% product page (physical properties, round wire temper table, alloy description)",
      "type": "datasheet",
      "url": "https://fiskalloy.com/product/c21000/"
    },
    {
      "title": "Fisk Alloy: C21000 Gilding, 95% PDF (composition, specifications, fabrication index, round, square and rolled flat temper tables)",
      "type": "datasheet",
      "url": "https://fiskalloy.com/pdf/c21000"
    },
    {
      "title": "Aviva Metals: C21000 Gilding Brass page (composition, physical properties, mechanical properties by temper, fabrication, typical uses)",
      "type": "datasheet",
      "url": "https://www.avivametals.com/collections/copper-alloys/beryllium-copper/c21000-gilding-brass-1"
    },
    {
      "title": "Aurubis: Technical Datasheet C22000 (CuZn10), 18 08 US",
      "type": "datasheet",
      "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf"
    },
    {
      "title": "Wikipedia: Gilding metal (history, uses, composition)",
      "type": "database",
      "url": "https://en.wikipedia.org/wiki/Gilding_metal",
      "year": 2026
    },
    {
      "title": "Wikipedia: Tombac (name and history of high-copper brass; zinc range not used)",
      "type": "database",
      "url": "https://en.wikipedia.org/wiki/Tombac",
      "year": 2026
    },
    {
      "title": "The Hendrix Group archive: stress corrosion cracking (season cracking) of brasses",
      "type": "report",
      "url": "https://hghouston.com/archive/material-property-data/copper-and-copper-alloys/brasses/sc-cracking"
    },
    {
      "title": "ATSDR ToxFAQs: Lead",
      "type": "report",
      "url": "https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=93&toxid=22"
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Copper",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Zinc",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf",
      "year": 2026
    }
  ],
  "gaps": [
    "Copper and zinc GHS classification not read: PubChem was blocked by a browser check, and a copper granular SDS link returned a web page rather than a PDF. No GHS code is entered for the metal; the health entry relies on lead only.",
    "Fisk product page prints a metric density of 8.94 g/cm3 for C21000, which conflicts with Wieland (8.86 g/cm3) and Aviva (specific gravity 8.86). The Fisk value is not used.",
    "Aviva prints a solidus of 1920 °F and a liquidus of 1950 °F, which conflicts with Fisk (solidus 1,750 °F or 954 °C, liquidus 1,920 °F or 1049 °C). The Fisk pair is used. Aviva prints the physical properties in US units only, so no Aviva metric value is used.",
    "Fisk prints a modulus of rigidity and electrical conductivity in a unit that does not parse (0.33 MS·cm). Neither value is used. The Wieland value of 33 MS/m matches 56 %IACS.",
    "Wieland prints yield strength and elongation for annealed and half-hard tempers only in brackets, marked for information only. Those figures are not recorded. Aviva gives yield in ksi (H02 40 ksi, H04 50 ksi) on a US-only page, and it is not recorded to keep one unit system per row.",
    "Wieland prints hardness only in brackets (HV 45 to 75 for R230 and so on), so no hardness value is recorded.",
    "Strength values for sheet and strip come from Wieland and Aviva; Fisk minimum values are for round wire and are not comparable with the flat-product rows. No ASTM B36 text was opened, so no specification minimum is recorded for C21000 sheet.",
    "No dezincification statement or test for C21000 was read. The dezincification claim in the corrosion block is for the CuZn10 grade (C22000) only.",
    "No threshold stress, time to crack or service rating for season cracking of C21000 was printed in the sources read.",
    "Tombac: the name is not printed on the Wieland or Aurubis pages. Wikipedia gives a zinc range of 5 to 20 % for tombac, but that page carries maintenance tags, so the range is not used. The file covers CuZn10 (C22000) as the tombac-range grade.",
    "CuZn15 (C23000) is named in the Wieland brass alloys table (EN CW502L, JIS C2300), but no physical or mechanical property for it was read, so the file has no CuZn15 values.",
    "Wieland prints CuZn10 CW501L; the CuZn5 CW500L code is confirmed by the Wieland M05 datasheet heading and the table row M05. The EN designation for CuZn5 is therefore CW500L, not CW501L.",
    "Concast and the Aviva C21000 page with a metric column were not reachable (HTTP 404 on the URLs tried), so no Concast value is used.",
    "No space-environment data (outgassing, atomic oxygen, cold welding, radiation) were read for C21000 or C22000. tags.environments is empty for this reason, and the applications listed are terrestrial uses.",
    "No CAS number was read; the alloy is identified by its UNS number.",
    "Media: no image was fetched or checked for this profile."
  ],
  "story": {
    "why": "Gilding metal is chosen for deep drawing and coining. Wieland calls it the historic penny alloy and says it is the usual choice for deep-drawn bullet jackets and coined products. It has 95 % copper, a density of 8.86 g/cm3, a thermal conductivity of 234 W/(m·K) at room temperature and a conductivity of 56 %IACS. Its main weakness is season cracking in ammonia when cold-forming stress is left in the part.",
    "uses": [
      {
        "where": "Electrical connectors and rotor bars",
        "line": "Aviva lists connectors and rotor bars for AC motors as typical uses. Wieland names electrical applications where performance requirements preclude standard copper."
      },
      {
        "where": "Fasteners and connector components",
        "line": "Fisk lists connector components and fasteners. Aviva lists fasteners among its typical uses."
      },
      {
        "where": "Bullet jackets, primers, coins and medals",
        "line": "Aviva lists bullet jackets, primers, fuse caps and small arm ammunition, and coins, medals and tokens among its typical uses. Wikipedia says gilding metal was used for bullet jackets and for shell casings melted into US pennies. These are not space applications, and none of them fits the space application list, so they are not in the uses block."
      }
    ],
    "can_do": [
      {
        "label": "Form cold",
        "line": "Aviva and Fisk both rate the capacity for cold working as excellent, and Aviva gives 12 % elongation in half-hard H02 and 45 % in annealed OS050.",
        "scope": "material",
        "value": "Excellent cold-working rating"
      },
      {
        "label": "Carry heat",
        "line": "Thermal conductivity is 234 W/(m·K) at room temperature (Wieland, metric column).",
        "benchmark": "thermal_conductivity",
        "scope": "material",
        "value": "234 W/(m·K)"
      },
      {
        "label": "Carry current",
        "line": "Electrical conductivity is 56 %IACS (Wieland and Aviva).",
        "scope": "material",
        "value": "56 %IACS"
      },
      {
        "label": "Strength by temper",
        "line": "Wieland gives annealed sheet 235 to 275 MPa, half-hard H02 290 to 360 MPa, hard H04 345 to 405 MPa and spring H08 415 to 470 MPa.",
        "scope": "material",
        "value": "235 to 470 MPa"
      },
      {
        "label": "Weight",
        "line": "Density is 8.86 g/cm3 (Wieland, metric column).",
        "benchmark": "density",
        "scope": "material",
        "value": "8.86 g/cm3"
      },
      {
        "label": "Melting",
        "line": "The solidus is 954 °C and the liquidus is 1049 °C (Fisk, metric column).",
        "scope": "material",
        "value": "954 to 1049 °C"
      },
      {
        "label": "Expansion",
        "line": "The coefficient of thermal expansion is 18.0 ppm/K from 0 to 300 °C (Wieland).",
        "benchmark": "cte",
        "scope": "material",
        "value": "18.0 ppm/K"
      }
    ],
    "compare": "The [copper profile](/profiles/copper/) covers the pure metal. The [cartridge brass profile](/profiles/cartridge-brass/) covers the 70/30 brass, which is stronger and has a higher zinc content, and it has the same season-cracking weakness. C21000 is the copper-rich end of the same family; the 90/10 CuZn10 grade (C22000) sits between the two.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Thermal conductivity",
        "benchmark": "thermal_conductivity",
        "scope": "material"
      },
      {
        "label": "Thermal expansion",
        "benchmark": "cte",
        "scope": "material"
      }
    ],
    "handling": [
      "Specify the temper: annealed sheet is 235 to 275 MPa tensile and spring H08 is 415 to 470 MPa (Wieland).",
      "Stress-relieve after cold forming (drawing, pressing, spinning, bending), and keep parts out of ammonia and amine atmospheres.",
      "The alloy contains lead at 0.05 % at most, so machining chips and dust are a lead source; the ATSDR advice applies (this is our inference from the advice, not a statement in the source)."
    ],
    "good_for": [
      "Deep-drawn and coined parts, where good cold working and a ductile temper are the main criteria.",
      "Electrical connectors and fasteners that need more strength than copper with moderate conductivity (56 %IACS).",
      "Parts where a bronze colour and a copper-rich alloy are needed, as with the CuZn10 grade."
    ],
    "watch_out": [
      "Season cracking in ammonia or amine atmospheres when cold-forming stress is left in the part.",
      "Machinability is poor (Fisk index 1), so do not choose this alloy for machined parts without a trial.",
      "Lead at 0.05 % at most is still a health hazard in the sources.",
      "No dezincification or space-environment data were read for C21000; the dezincification claim is for the 90/10 CuZn10 grade only."
    ],
    "verdict": "Gilding metal 95/5 is the copper-rich brass for deep drawing and coining. It conducts heat at 234 W/(m·K) and electricity at 56 %IACS, with annealed tensile strength of 235 to 275 MPa (Wieland) and spring temper up to 470 MPa. Its main weakness is season cracking in ammonia under residual stress, and the fix is a stress-relief anneal. The CuZn10 grade (C22000, the tombac range) is in the file as a second grade. No space-environment result, no C21000 corrosion rating and no copper GHS classification were found in the pages read.",
    "recipe": {
      "line": "Gilding metal is a copper-zinc alloy with 94.0 to 96.0 wt% copper, zinc as the remainder (nominal 5 wt%), and at most 0.05 wt% lead and 0.05 wt% iron (Aviva and Fisk). Wieland prints the reference composition as Cu 95 % and Zn remainder. It is supplied as wrought strip, sheet, wire and rod (ASTM B36 and B134) and is made soft by annealing between 427 and 788 °C (Fisk).",
      "parts": [
        {
          "name": "Copper",
          "symbol": "Cu",
          "role": "Main metal and matrix of the alloy (limits from Aviva and Fisk; nominal from Wieland)."
        },
        {
          "name": "Zinc",
          "symbol": "Zn",
          "role": "The alloying element that makes the brass and raises strength above pure copper, with moderate conductivity still kept (Wieland)."
        },
        {
          "name": "Lead",
          "symbol": "Pb",
          "role": "Impurity limit printed on the Aviva and Fisk pages."
        },
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "Impurity limit printed on the Aviva and Fisk pages."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The lead in C21000 is the main health concern in these sources. The sources give the health effects of lead but no exposure limit for brass dust.",
        "points": [
          {
            "label": "Lead in the alloy",
            "line": "C21000 has 0.05 % lead at most (Aviva and Fisk). The ATSDR says lead can affect almost every organ and system, and HHS considers lead and lead compounds reasonably anticipated to be human carcinogens."
          }
        ],
        "level": 2,
        "verdict": "Low-lead alloy"
      },
      {
        "title": "If it fails",
        "lead": "The failure route in these sources is chemical (ammonia) and it is driven by residual stress from cold forming.",
        "points": [
          {
            "label": "Season cracking",
            "line": "Cold forming leaves stress, and in an ammonia or amine atmosphere the alloy can crack. The Hendrix Group describes the cracking, and recommends stress relief and low zinc."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Pick the temper",
            "line": "Annealed sheet is 235 to 275 MPa tensile (Wieland) and the spring temper H08 is 415 to 470 MPa. Elongation falls from 45 % in annealed OS050 (Aviva) to 4 % in H08."
          },
          {
            "label": "Stress relief",
            "line": "Stress-relieve parts after cold forming, as the Hendrix Group advises, and keep them out of ammonia and amine atmospheres."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 33,
    "unreachable": 3,
    "caveats": 5,
    "note": "Values were read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry. Unreachable or unusable: Aviva and Concast C21000 URLs tried first (HTTP 404), PubChem copper page (browser check), and a copper SDS link (returned HTML). Caveats: strength values for sheet are typical or range values from manufacturer tables, and the Fisk values are minimum values for round wire, not comparable with flat product; the Fisk metric density and melting point conflict with Wieland and Aviva and the Fisk melting pair is used; the Aurubis CuZn10 properties are for the soft condition and the H tempers, with form not stated per row; the season-cracking rating for C21000 is unknown in the sources."
  },
  "sources": {
    "wieland-m05": {
      "title": "Wieland, M05 CuZn5 | C21000 | CW500L rolled products datasheet: chemical composition, physical properties, mechanical properties by temper (ASTM B36), bendability, thermal stress relaxation",
      "url": "https://www.wieland.com/hu/content/download/12535/file/M05_RP_EN.pdf",
      "kind": "datasheet",
      "license": "Manufacturer datasheet (cited, not reproduced)"
    },
    "wieland-brass-table": {
      "title": "Wieland, brass alloys table: rows M05 (CuZn5, CW500L, C21000, C2100) and M10 (CuZn10, CW501L, C22000, C2200)",
      "url": "https://www.wieland.com/products/brass-alloys",
      "kind": "datasheet",
      "license": "Manufacturer web page (cited, not reproduced)"
    },
    "aviva-c21000": {
      "title": "Aviva Metals, C21000 Gilding Brass page: chemical composition, physical properties (US units), mechanical properties by temper (typical), fabrication ratings, typical uses, specifications",
      "url": "https://www.avivametals.com/collections/copper-alloys/beryllium-copper/c21000-gilding-brass-1",
      "kind": "datasheet",
      "license": "Supplier web page (cited, not reproduced)"
    },
    "fisk-c21000": {
      "title": "Fisk Alloy, C21000 Gilding, 95% product page: composition limits, physical properties (metric and US), round wire temper table, alloy description and listed uses",
      "url": "https://fiskalloy.com/product/c21000/",
      "kind": "datasheet",
      "license": "Supplier web page (cited, not reproduced)"
    },
    "fisk-c21000-pdf": {
      "title": "Fisk Alloy, C21000 Gilding, 95% PDF: composition, specifications (ASTM B36, ASTM B134), fabrication index, round, square and rolled flat temper tables",
      "url": "https://fiskalloy.com/pdf/c21000",
      "kind": "datasheet",
      "license": "Supplier document (cited, not reproduced)"
    },
    "aurubis-c22000": {
      "title": "Aurubis, Technical Datasheet C22000 (CuZn10), 18 08 US: composition, physical properties, mechanical properties by temper, fabrication, typical uses, specifications",
      "url": "https://www.aurubis.be/en/dam/jcr:50283e48-c222-4671-bde3-5bd1bd437df3/c22000-cuzn10-us.pdf",
      "kind": "datasheet",
      "license": "Manufacturer datasheet (cited, not reproduced)"
    },
    "wiki-gilding-metal": {
      "title": "Gilding metal (Wikipedia): composition, history, bullet jackets and US penny use",
      "url": "https://en.wikipedia.org/wiki/Gilding_metal",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0 (cited, not reproduced)"
    },
    "wiki-tombac": {
      "title": "Tombac (Wikipedia): name, history and use of high-copper brass; page carries maintenance tags",
      "url": "https://en.wikipedia.org/wiki/Tombac",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0 (cited, not reproduced)"
    },
    "hgh-scc": {
      "title": "The Hendrix Group, Material Property Data: copper and copper alloys, brasses, stress corrosion cracking",
      "url": "https://hghouston.com/archive/material-property-data/copper-and-copper-alloys/brasses/sc-cracking",
      "kind": "web",
      "license": "Technical archive page (cited, not reproduced)"
    },
    "atsdr-lead": {
      "title": "ATSDR ToxFAQs: Lead (Agency for Toxic Substances and Disease Registry, U.S. CDC)",
      "url": "https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=93&toxid=22",
      "kind": "report",
      "license": "U.S. government public domain (cited, not reproduced)"
    },
    "usgs-mcs2026-copper": {
      "title": "Mineral Commodity Summaries 2026: Copper",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-mcs2026-zinc": {
      "title": "Mineral Commodity Summaries 2026: Zinc",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/gilding-metal/"
}