{
  "spore": "profile",
  "id": "cartridge-brass",
  "spore_version": "0.2",
  "family": "copper-alloys",
  "name": "Cartridge brass 70/30",
  "abbreviation": "C260",
  "role": "cold-working copper-zinc alloy",
  "category": "metals",
  "type": "copper-alloys",
  "summary": "Cartridge brass 70/30 (UNS C26000, CuZn30, EN CW505L) is a copper-zinc alloy with 70 % copper and 30 % zinc, with lead held to 0.07 % maximum. It is the classic cold-forming brass: Aviva rates its capacity for being cold worked as excellent, and season cracking, named after the brass cartridges in which it was first found in the 1920s, is its classic failure mode. Its density is 8.53 g/cm3, its thermal conductivity is 121.2 W/(m·K) at 20 °C and its electrical conductivity is 28 %IACS at 68 °F. Its strength depends on temper: Aviva's typical 1 in values run from 324 MPa tensile in annealed OS050 to 524 MPa in hard H04, and Fisk's minimum round wire values are 540 MPa for H02 and 700 MPa for H04. The alloy is at risk from ammonia under residual stress, and a stress-relief anneal is the usual cure.\n",
  "best_for": "Cold-formed and deep-drawn parts such as cartridge cases, fasteners, pins and radiator parts, where good cold working and a ductile temper matter most",
  "weakest_at": "Season cracking in ammonia or amine atmospheres when residual stress from cold forming is left in the part",
  "identity": {
    "formula": "CuZn30, UNS C26000: copper 68.5 to 71.5 wt%, lead 0.07 wt% maximum, iron 0.05 wt% maximum, zinc remainder",
    "designations": [
      {
        "system": "UNS",
        "code": "C26000",
        "source": "aviva-c26000",
        "where": "Page title: C26000 Cartridge Brass \"70/30\""
      },
      {
        "system": "CDA",
        "code": "C260",
        "source": "fisk-c26000",
        "where": "Page heading: C260 Cartridge Brass (CuZn30)"
      },
      {
        "system": "EN name",
        "code": "CuZn30",
        "source": "aviva-c26000",
        "where": "Line: EN equivalent for this alloy CuZn30"
      },
      {
        "system": "EN name",
        "code": "CW505L",
        "source": "wieland-brass-alloys",
        "where": "Brass alloys table, row M30 (M30/M34), EN No. column"
      },
      {
        "system": "JIS",
        "code": "C2600",
        "source": "wieland-brass-alloys",
        "where": "Brass alloys table, row M30 (M30/M34), JIS-No. column"
      },
      {
        "system": "ASTM",
        "code": "B36",
        "note": "bar, sheet and plate, as listed on the Aviva page",
        "source": "aviva-c26000",
        "where": "Specifications list, ASTM B36 for bar, sheet and plate"
      },
      {
        "system": "Trade name",
        "code": "Cartridge Brass",
        "source": "fisk-c26000",
        "where": "Page heading: C260 Cartridge Brass (CuZn30)"
      }
    ],
    "source": "aviva-c26000",
    "where": "Chemical Composition table on the Aviva product page (Cu 68.5-71.5, Pb 0.07 max, Fe 0.05 max, Zn rem, nominal Cu 70 and Zn 30); the copper, zinc and lead limits also appear on the Fisk C260 page, and the iron limit on the Concast C26000 page."
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "mechanisms",
      "electronics-and-chips",
      "thermal-control"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, C26000 (Aviva)",
      "value": 8.53,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temperature": "20 °C",
        "unit_in_source": "0.308 lb/in3 at 68 °F (US Customary column)"
      },
      "method": "Value printed in the metric column of a supplier's physical properties table; Concast prints the same 8.53 g/cm3",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Density row, metric column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Solidus, C26000 (Aviva)",
      "value": 916,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "unit_in_source": "1680 °F (US column)",
        "pressure": "not stated"
      },
      "method": "Value printed in the metric column of a supplier's physical properties table; Concast prints 916 °C",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Melting Point Solid row, metric column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Liquidus, C26000 (Aviva)",
      "value": 954,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "unit_in_source": "1750 °F (US column)",
        "pressure": "not stated"
      },
      "method": "Value printed in the metric column of a supplier's physical properties table; Concast prints 954 °C",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Melting Point Liquid row, metric column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity at 20 °C, C26000 (Aviva)",
      "value": 121.2,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temperature": "20 °C",
        "temper": "not stated; one value printed for the alloy",
        "unit_in_source": "70.0 Btu·ft/(hr·ft2·°F) at 68 °F (US column)"
      },
      "method": "Value printed in the metric column of a supplier's physical properties table; Concast prints 121.2 W/m K at 20 °C",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Thermal Conductivity row, metric column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, 20 to 300 °C (Aviva)",
      "value": 20,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temperature": "20 to 300 °C",
        "temper": "not stated",
        "unit_in_source": "20.0 per °C (20-300 °C)"
      },
      "method": "Printed as per °C; this is 10^-6 per kelvin, the same unit as ppm/K, so the number is copied without conversion",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Coefficient of Thermal Expansion row, metric column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_conductivity",
      "label": "Electrical conductivity, C26000 (Aviva)",
      "value": 28,
      "bound": "exact",
      "unit": "%IACS",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "not stated",
        "temperature": "68 °F (20 °C)",
        "unit_in_source": "28 %IACS at 68 °F (US column)"
      },
      "method": "Value printed in the US column of a supplier's physical properties table; the metric column for the same row (0.164 MegaSiemens/cm at 20 °C) is not converted here",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Electrical Conductivity row, US column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, annealed C26000 (Aviva)",
      "value": 6.15,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "not stated in the Aviva row",
        "temperature": "20 °C",
        "unit_in_source": "37.0 ohms·cmil/ft at 68 °F (US column)"
      },
      "method": "Value printed in the metric column of a supplier's physical properties table",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Electrical Resistivity row, metric column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity in tension, C26000 (Aviva)",
      "value": 110000,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "not stated",
        "unit_in_source": "16000 ksi (US column)"
      },
      "method": "Value printed in the metric column of a supplier's physical properties table; the Fisk page prints 110 MPa for the same row, which is a units error and is not used",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Modulus of Elasticity in Tension row, metric column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "shear_modulus",
      "label": "Modulus of rigidity, C26000 (Aviva)",
      "value": 41370,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "not stated",
        "unit_in_source": "6000 ksi (US column)"
      },
      "method": "Value printed in the metric column of a supplier's physical properties table",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Modulus of Rigidity row, metric column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat capacity, C26000 (Aviva)",
      "value": 377.1,
      "bound": "exact",
      "unit": "J/(kg·K)",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temperature": "293 K (20 °C)",
        "unit_in_source": "0.09 Btu/lb/°F at 68 °F (US column)"
      },
      "method": "Value printed in the metric column of a supplier's physical properties table",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Physical Properties table, Specific Heat Capacity row, metric column",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, annealed OS050 flat product, 1 in rows (typical)",
      "value": 324,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "OS050, annealed",
        "product_form": "flat product (sheet, strip and plate), 1 in rows",
        "basis": "typical value, 20 °C",
        "unit_in_source": "47 ksi at 0.04 in rows (US column)"
      },
      "method": "Typical value (TYP) printed in a supplier's mechanical properties table by temper, metric 1 in row; not a minimum",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Mechanical Properties by Temper table, flat products, row OS050, column Tensile 1 in (MPa)",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength 0.05 % under load, annealed OS050 flat product, 1 in rows (typical)",
      "value": 103,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "OS050, annealed",
        "product_form": "flat product (sheet, strip and plate), 1 in rows",
        "basis": "typical value, 20 °C",
        "measure": "0.05 % under load"
      },
      "method": "Typical value (TYP) printed in a supplier's mechanical properties table, metric 1 in row; the yield definition is 0.05 % under load, not 0.2 % offset",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Mechanical Properties by Temper table, flat products, row OS050, column YS 0.05% UL 1 in (MPa)",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, annealed OS050 flat product, 1 in rows (typical)",
      "value": 62,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "OS050, annealed",
        "product_form": "flat product (sheet, strip and plate), 1 in rows",
        "gauge_length": "1 in",
        "basis": "typical value, 20 °C"
      },
      "method": "Typical value (TYP) printed in a supplier's mechanical properties table, metric 1 in row",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Mechanical Properties by Temper table, flat products, row OS050, column Elong. 1 in (%)",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, half-hard H02 flat product, 1 in rows (typical)",
      "value": 427,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "H02, half hard",
        "product_form": "flat product (sheet, strip and plate), 1 in rows",
        "basis": "typical value, 20 °C",
        "unit_in_source": "62 ksi at 0.04 in rows (US column)"
      },
      "method": "Typical value (TYP) printed in a supplier's mechanical properties table, metric 1 in row; not a minimum",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Mechanical Properties by Temper table, flat products, row H02, column Tensile 1 in (MPa)",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength 0.05 % under load, half-hard H02 flat product, 1 in rows (typical)",
      "value": 359,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "H02, half hard",
        "product_form": "flat product (sheet, strip and plate), 1 in rows",
        "basis": "typical value, 20 °C",
        "measure": "0.05 % under load"
      },
      "method": "Typical value (TYP) printed in a supplier's mechanical properties table, metric 1 in row",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Mechanical Properties by Temper table, flat products, row H02, column YS 0.05% UL 1 in (MPa)",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, half-hard H02 flat product, 1 in rows (typical)",
      "value": 25,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Aviva)",
        "temper": "H02, half hard",
        "product_form": "flat product (sheet, strip and plate), 1 in rows",
        "gauge_length": "1 in",
        "basis": "typical value, 20 °C"
      },
      "method": "Typical value (TYP) printed in a supplier's mechanical properties table, metric 1 in row",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Mechanical Properties by Temper table, flat products, row H02, column Elong. 1 in (%)",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, half-hard H02 round wire (minimum)",
      "value": 540,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Fisk C260)",
        "temper": "H02, 1/2 hard",
        "product_form": "round wire, mill limits 0.0254 to 3.264 mm",
        "measure": "minimum",
        "unit_in_source": "79.0 ksi (English column)"
      },
      "method": "Minimum value printed in a supplier's round wire temper table, metric column; wire, not rod, so not comparable with the flat-product rows",
      "status": "ground",
      "source": "fisk-c26000",
      "where": "Round Wire table, metric block, row 1/2 Hard H02, column Tensile Strength Min (MPa)",
      "source_detail": {
        "title": "Fisk Alloy, C260 Cartridge Brass (CuZn30) product page: composition, physical properties, round wire temper table, alloy description",
        "url": "https://fiskalloy.com/product/c26000/",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, hard H04 round wire (minimum)",
      "value": 700,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "C26000 (Fisk C260)",
        "temper": "H04, hard",
        "product_form": "round wire, mill limits 0.0254 to 3.264 mm",
        "measure": "minimum",
        "unit_in_source": "102 ksi (English column)"
      },
      "method": "Minimum value printed in a supplier's round wire temper table, metric column; wire, not rod",
      "status": "ground",
      "source": "fisk-c26000",
      "where": "Round Wire table, metric block, row Hard H04, column Tensile Strength Min (MPa)",
      "source_detail": {
        "title": "Fisk Alloy, C260 Cartridge Brass (CuZn30) product page: composition, physical properties, round wire temper table, alloy description",
        "url": "https://fiskalloy.com/product/c26000/",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "machinability_rating",
      "label": "Machinability rating, C26000 bar (supplier index)",
      "value": 30,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "C26000",
        "temper": "not stated",
        "basis": "relative index; the base (100 = reference alloy) is not printed on this page"
      },
      "method": "Index printed in the Fabrication table of the supplier's page; a relative rating, not a measured property",
      "status": "ground",
      "source": "aviva-c26000",
      "where": "Fabrication table, Machinability rating row",
      "source_detail": {
        "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
        "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
        "kind": "datasheet",
        "license": "Supplier web page (cited, not reproduced)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Ammonia or amine atmospheres with tensile stress (season cracking)",
      "headline": "Season cracking was first found in brass cartridges in the 1920s, where cold-formed cases stored in ammonia-rich stables cracked.",
      "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 cold working such as pressing, spinning, drawing and bending leaves internal stresses that can cause cracking unless they are removed by stress relief. Wikipedia says the problem was resolved by annealing the cases and storing the cartridges elsewhere.",
      "rating": "moderate",
      "conditions": {
        "basis": "qualitative description for brasses in general; no threshold stress or time to crack for C26000 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 stress relief; Wikipedia Brass article, season cracking section"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Lead: C26000 contains 0.07 wt% lead at most (Aviva and Fisk limits). The ATSDR ToxFAQ says lead can affect almost every organ and system, and that the U.S. Department of Health and Human Services has determined that lead and lead compounds are 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 (pressing, spinning, drawing, bending) together with an ammonia or amine atmosphere",
        "consequence": "Cracking, which the Hendrix Group says is liable to occur longitudinally in drawn tube that has not been stress-relieved",
        "severity": "moderate",
        "source": "hgh-scc",
        "where": "Cold working and stress relief sections"
      },
      {
        "mode": "Poor stress relaxation in spring service",
        "trigger": "Use as a spring",
        "consequence": "Fisk says the alloy has poor stress relaxation characteristics and does not make a particularly good spring material",
        "severity": "low",
        "source": "fisk-c26000",
        "where": "Alloy description paragraph on the Fisk C260 page"
      }
    ],
    "side_effects": [
      {
        "text": "Concast lists C26000 under its lead-free products, while the same alloy carries up to 0.07 % lead",
        "affects": "Potable-water plumbing (Concast lists plumbing among the uses of C26000)",
        "source": "concast-c26000",
        "where": "Lead-free products list and Plumbing row of the Concast C26000 page"
      }
    ],
    "handling": [
      {
        "text": "Specify the temper: Aviva's typical 1 in flat values run from 324 MPa tensile in annealed OS050 to 524 MPa in hard H04, and Fisk's round wire minimum runs from 540 MPa (H02) to 700 MPa (H04).",
        "source": "aviva-c26000",
        "where": "Mechanical Properties by Temper table; Fisk Round Wire table"
      },
      {
        "text": "Stress-relieve parts after cold forming. The Hendrix Group says the optimum stress relief depends on the alloy and lies within one half to one hour at 250 to 300 °C for brasses.",
        "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": "Avoid exposure to sources of lead. The ATSDR advice applies to machining chips and dust from the alloy, which contain lead (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; C26000 is a 70 % copper alloy.",
        "source": "hgh-scc",
        "where": "Effect of composition section"
      },
      {
        "text": "Anneal the cases to remove the residual stress from cold forming and store the cartridges elsewhere, as was done after the 1920s British Indian Army failures (Wikipedia).",
        "source": "wiki-brass",
        "where": "Season cracking section"
      }
    ]
  },
  "uses": [
    {
      "application": "mechanisms",
      "device": "Fasteners, pins, rivets and eyelets",
      "example": "Concast lists eyelets, fasteners, grommets, pins, rivets and screws among the applications of C26000. Aviva lists springs, chain and bead chain as typical uses.",
      "source": "concast-c26000",
      "where": "Fasteners row of the Concast C26000 page; Typical Uses list on the Aviva page"
    },
    {
      "application": "electronics-and-chips",
      "device": "Electrical terminals, lamp fixtures and flashlight shells",
      "example": "Concast lists flashlight shells, lamp fixtures, reflectors, screw shells and terminal connectors under electrical uses. These are terrestrial uses; no source names a space system.",
      "source": "concast-c26000",
      "where": "Electrical row of the Concast C26000 page"
    },
    {
      "application": "thermal-control",
      "device": "Radiator cores, radiator tanks and heat exchangers",
      "example": "Concast lists radiator cores, radiator tanks and heater cores under automotive uses. Aviva lists heat exchangers among its typical uses. These are terrestrial uses; no source names a space system.",
      "source": "concast-c26000",
      "where": "Automotive row of the Concast C26000 page; Industrial row"
    }
  ],
  "supply": [
    {
      "subject": "Copper (mine production, copper content, 2025e), about 70 % of the alloy",
      "producers": [
        {
          "country": "Chile",
          "share_percent": 23,
          "year": 2025
        },
        {
          "country": "Congo (Kinshasa)",
          "share_percent": 13.9,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 11.7,
          "year": 2025
        },
        {
          "country": "China",
          "share_percent": 7.8,
          "year": 2025
        },
        {
          "country": "Russia",
          "share_percent": 5.7,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "U.S. Final 2025 List of Critical Minerals (copper added, per the USGS copper summary)",
          "listed": true
        }
      ],
      "recycling": "USGS: brass and wire-rod mills accounted for approximately 80 % of the total copper recovered from scrap. Copper recovered from scrap contributed about 30 % of the U.S. copper supply.",
      "substitutes": [],
      "source": "usgs-mcs2026-copper",
      "where": "World Mine and Refinery Production and Reserves table, mine production 2025e (world total 23,000 thousand t; shares calculated by Space Mushroom from the printed values 5,300, 3,200, 2,700, 1,800 and 1,300 thousand t); Critical minerals paragraph; Recycling paragraph"
    },
    {
      "subject": "Zinc (mine production, zinc content, 2025e), about 30 % of the alloy",
      "producers": [
        {
          "country": "China",
          "share_percent": 31.5,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 11.5,
          "year": 2025
        },
        {
          "country": "Australia",
          "share_percent": 8.5,
          "year": 2025
        },
        {
          "country": "India",
          "share_percent": 6.7,
          "year": 2025
        },
        {
          "country": "Mexico",
          "share_percent": 6,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: refined zinc produced in the United States was recovered from secondary materials at both primary and secondary smelters, including galvanizing residues and crude zinc oxide from electric arc furnace dust.",
      "substitutes": [
        "USGS: aluminum and plastics substitute for galvanized sheet in automobiles; many elements are substitutes for zinc in chemical, electronic and pigment uses. The summary names no substitute for zinc in brass."
      ],
      "source": "usgs-mcs2026-zinc",
      "where": "World Mine Production and Reserves table, 2025e (world total 13,000 thousand t; shares calculated by Space Mushroom from the printed values 4,100, 1,500, 1,100, 870 and 780 thousand t); Recycling; Substitutes"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Aviva Metals: C26000 Cartridge Brass \"70/30\" product page, chemical composition, physical properties, mechanical properties by temper, machinability",
      "type": "datasheet",
      "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30"
    },
    {
      "title": "Fisk Alloy: C260 Cartridge Brass (CuZn30) product page, physical properties, round wire temper table, alloy description",
      "type": "datasheet",
      "url": "https://fiskalloy.com/product/c26000/"
    },
    {
      "title": "Concast (Wieland): C26000 spec sheet, applications, composition, physical and mechanical properties",
      "type": "datasheet",
      "url": "https://www.concast.com/c26000.php"
    },
    {
      "title": "Wieland: brass alloys table, row M30 (CuZn30, CW505L, C26000, C2600)",
      "type": "datasheet",
      "url": "https://www.wieland.com/products/brass-alloys"
    },
    {
      "title": "Wikipedia: Brass (cartridge brass C260 row, season cracking, lead content)",
      "type": "database",
      "url": "https://en.wikipedia.org/wiki/Brass",
      "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": [
    "No dezincification statement or depth data for C26000 was read. The Aviva C26000 page has no dezincification note, and the Wikipedia passages read cover dezincification-resistant alloys, not this one.",
    "The Hendrix test (10 % ammonia, 3.7 % water vapour, 35 °C) is an accelerated indicative test, not a service limit. No time to crack or threshold stress for C26000 was printed in the sources.",
    "The Fisk C260 page prints a metric density of 8.94 g/cm3, which conflicts with its own 0.308 lb/in3 (8.53 g/cm3) and with Aviva and Concast. It also prints a melting range of 954 to 1,049 °C, which conflicts with Aviva and Concast (916 to 954 °C). Neither Fisk value is used.",
    "The Fisk page prints an elastic modulus of 110 MPa, a units error. Aviva prints 110000 MPa, which is used.",
    "Strength values are typical values from Aviva's flat-product and 1 in rod rows, and minimum values from Fisk's round wire table. No minimum for strip, sheet or rod against the ASTM B36 text was read, and the ASTM B36 text itself was not opened.",
    "The hardness values on the Aviva table (Rockwell B 70 for H02, B 82 for H04) are not recorded; the hardness names are not in the property canon.",
    "The machinability index of 30 is a supplier's relative rating. The base of the scale is not printed on the Aviva page.",
    "Conflict on springs: Aviva lists springs among typical uses, while Fisk says the alloy does not make a particularly good spring material. Both are recorded in the file.",
    "Conflict on soldering: the Fisk and Aviva fabrication tables rate soldering as excellent. A Fisk sentence says the solderability is severely impaired by the high zinc content. The fabrication rating is not used and the sentence is not used.",
    "Lead is held to 0.07 % at most. No lead supply profile was written because lead is a trace element here, and the USGS lead summary was not used for this alloy.",
    "Refined zinc net import reliance was not used because the column headers of the USGS table were not read.",
    "No GHS classification or exposure limit for lead was read. The ATSDR ToxFAQ gives the health effects only.",
    "No CAS number was read; the alloy is identified by its UNS number.",
    "No space-environment data for C26000 were read: no outgassing, atomic-oxygen, cold-welding or radiation result. The tags.environments list is empty for this reason, and the applications listed are terrestrial uses.",
    "The National Bronze C26000 pages returned 404 and the PDF was not readable, so no National Bronze value is used.",
    "Designations: BS, DIN and AFNOR codes were not read. The JIS code C2600 is from the Wieland table, which is a cross-reference table, not a JIS standard text.",
    "Media: no image was fetched or checked for this profile."
  ],
  "story": {
    "why": "Cartridge brass is chosen for cold working. Aviva rates its capacity for being cold worked as excellent, and Fisk rates cold working as excellent too. It conducts heat at 121.2 W/(m·K) at 20 °C (Aviva) and electricity at 28 %IACS. Its density is 8.53 g/cm3. The lead content is at most 0.07 %, and the alloy's main weakness is season cracking in ammonia.",
    "uses": [
      {
        "where": "Fasteners, pins and rivets",
        "line": "Concast lists eyelets, fasteners, grommets, pins, rivets and screws among the applications of C26000. Aviva lists springs, chain and bead chain as typical uses."
      },
      {
        "where": "Electrical parts and lamp fixtures",
        "line": "Concast lists flashlight shells, lamp fixtures, reflectors, screw shells and terminal connectors. These are terrestrial uses; no source names a space system."
      },
      {
        "where": "Radiator and heat-exchanger parts",
        "line": "Concast lists radiator cores, radiator tanks and heater cores. Aviva lists heat exchangers among its typical uses."
      }
    ],
    "can_do": [
      {
        "label": "Form cold",
        "line": "Aviva and Fisk both rate the capacity for being cold worked as excellent, and Aviva's flat product reaches 62 % elongation in the annealed OS050 temper.",
        "scope": "material",
        "value": "Excellent cold-working rating"
      },
      {
        "label": "Carry heat",
        "line": "Thermal conductivity is 121.2 W/(m·K) at 20 °C (Aviva, metric column).",
        "benchmark": "thermal_conductivity",
        "scope": "material",
        "value": "121.2 W/(m·K)"
      },
      {
        "label": "Carry current",
        "line": "Electrical conductivity is 28 %IACS at 68 °F (Aviva, US column).",
        "scope": "material",
        "value": "28 %IACS"
      },
      {
        "label": "Strength by temper",
        "line": "Aviva's typical tensile strength for flat product runs from 324 MPa annealed (OS050) to 524 MPa in H04. Fisk's minimum round wire values are 540 MPa for H02 and 700 MPa for H04.",
        "scope": "material",
        "value": "324 to 524 MPa typical"
      },
      {
        "label": "Weight",
        "line": "Density is 8.53 g/cm3 at 20 °C (Aviva, metric column).",
        "benchmark": "density",
        "scope": "material",
        "value": "8.53 g/cm3"
      },
      {
        "label": "Melting",
        "line": "The solidus is 916 °C and the liquidus is 954 °C (Aviva, metric column).",
        "scope": "material",
        "value": "916 to 954 °C"
      },
      {
        "label": "Expansion",
        "line": "The coefficient of thermal expansion is 20.0 ppm/K over 20 to 300 °C (Aviva, printed as per °C).",
        "benchmark": "cte",
        "scope": "material",
        "value": "20.0 ppm/K"
      }
    ],
    "compare": "The [copper profile](/profiles/copper/) covers the pure metal. The free-cutting brass profile in this set is the machinability reference among the brasses; C26000 has a supplier machinability rating of 30, and it is the better choice where cold forming matters more than machining.",
    "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: strength runs from 324 MPa typical in annealed OS050 flat product to 524 MPa in hard H04 flat product.",
      "Stress-relieve after cold forming (pressing, spinning, drawing, bending), and keep parts out of ammonia and amine atmospheres.",
      "The alloy contains lead at 0.07 % at most, so machining chips and dust are a lead source; the ATSDR advice to avoid lead exposure applies to them (this is our inference from the advice, not a statement in the source)."
    ],
    "good_for": [
      "Cold-formed and deep-drawn parts, where excellent cold working and a ductile temper are the main selection criteria.",
      "Fasteners, pins and rivets that need a tensile strength between about 324 MPa (annealed) and 524 MPa (H04), chosen by temper.",
      "Radiator and heat-exchanger parts that need good thermal conductivity, at 121.2 W/(m·K)."
    ],
    "watch_out": [
      "Season cracking in ammonia or amine atmospheres when cold-forming stress is left in the part.",
      "Aviva lists springs among its uses, but Fisk says the alloy does not make a good spring material because of its poor stress relaxation.",
      "Lead at 0.07 % at most is still a health hazard in the sources.",
      "The machinability rating of 30 is a supplier's relative index, and it is a poor choice where machinability is the main criterion."
    ],
    "verdict": "Cartridge brass 70/30 is the classic cold-forming brass. It gives 121.2 W/(m·K) thermal conductivity and 28 %IACS conductivity, with typical tensile strength from 324 to 524 MPa across the temper range, and it is rated excellent for cold working. Its main weakness is season cracking in ammonia when residual stress from forming is left in the part, and the fix is a stress-relief anneal. No dezincification data, no corrosion rate and no space-environment result were found in the pages read.",
    "recipe": {
      "line": "Cartridge brass is a copper-zinc alloy with 68.5 to 71.5 % copper, zinc as the remainder (nominal 30 %), and at most 0.07 % lead. Aviva and Concast also print the 0.05 % iron limit.",
      "parts": [
        {
          "name": "Copper",
          "symbol": "Cu",
          "role": "Main metal and matrix of the alloy (limits from Aviva, Fisk and Concast)."
        },
        {
          "name": "Zinc",
          "symbol": "Zn",
          "role": "The alloying element that makes the brass. Wikipedia's alloy table notes good cold working properties for C260 and says it is used for ammunition cases, plumbing and hardware."
        },
        {
          "name": "Lead",
          "symbol": "Pb",
          "role": "Impurity limit printed on the Aviva, Fisk and Concast pages."
        },
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "Impurity limit printed on the Aviva and Concast pages."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The lead in C26000 is the main health concern in these sources. They give the health effects of lead but no exposure limit for brass dust.",
        "points": [
          {
            "label": "Lead in the alloy",
            "line": "C26000 has 0.07 % lead at most (Aviva and Fisk). The ATSDR says lead can affect almost every organ and system, and the U.S. Department of Health and Human Services considers lead and lead compounds reasonably anticipated to be human carcinogens."
          },
          {
            "label": "Lead-free listing",
            "line": "Concast lists C26000 under its lead-free products. The source does not give the lead-free limit it uses."
          }
        ],
        "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 Wikipedia records the 1920s cartridge failures."
          },
          {
            "label": "Stiff springs",
            "line": "Fisk says the alloy has poor stress relaxation and does not make a particularly good spring material, although Aviva lists springs among its uses."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Pick the temper",
            "line": "Annealed OS050 flat product has 324 MPa typical tensile strength and 62 % elongation. Half-hard H02 has 427 MPa and 25 %. Hard H04 has 524 MPa and 8 %."
          },
          {
            "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": 19,
    "unreachable": 2,
    "caveats": 4,
    "note": "Values were read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry. Unreachable or unusable: National Bronze C26000 page (HTTP 404) and its PDF (not readable as text). Caveats: strength values are typical values from one supplier's flat-product table and minimum values from one supplier's round wire table, not from the ASTM B36 text; the Fisk metric density and melting range conflict with Aviva and Concast and were not used; the Fisk elastic modulus has a units error and was not used; the season-cracking test is accelerated and qualitative."
  },
  "sources": {
    "aviva-c26000": {
      "title": "Aviva Metals, C26000 Cartridge Brass \"70/30\" product page: chemical composition, physical properties, mechanical properties by temper, fabrication ratings, typical uses",
      "url": "https://www.avivametals.com/collections/brass-alloys/yellow-brass/c26000-cartridge-brass-70-30",
      "kind": "datasheet",
      "license": "Supplier web page (cited, not reproduced)"
    },
    "fisk-c26000": {
      "title": "Fisk Alloy, C260 Cartridge Brass (CuZn30) product page: composition, physical properties, round wire temper table, alloy description",
      "url": "https://fiskalloy.com/product/c26000/",
      "kind": "datasheet",
      "license": "Supplier web page (cited, not reproduced)"
    },
    "concast-c26000": {
      "title": "Concast (Wieland), C26000 spec sheet: composition, physical and mechanical properties, applications, lead-free products list",
      "url": "https://www.concast.com/c26000.php",
      "kind": "datasheet",
      "license": "Manufacturer web page (cited, not reproduced)"
    },
    "wieland-brass-alloys": {
      "title": "Wieland: brass alloys table, row M30 (EN designation CuZn30, EN No. CW505L, ASTM UNS-No. C26000, JIS-No. C2600)",
      "url": "https://www.wieland.com/products/brass-alloys",
      "kind": "datasheet",
      "license": "Manufacturer web page (cited, not reproduced)"
    },
    "wiki-brass": {
      "title": "Brass (Wikipedia): cartridge brass C260 row, season cracking history, lead content",
      "url": "https://en.wikipedia.org/wiki/Brass",
      "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/cartridge-brass/"
}