{
  "spore": "profile",
  "id": "alnico",
  "spore_version": "0.2",
  "family": "magnet-and-superconducting-alloys",
  "name": "Alnico permanent-magnet alloy",
  "abbreviation": "Alnico",
  "role": "permanent magnet",
  "category": "metals",
  "type": "magnet-alloys",
  "summary": "Alnico is an iron alloy of aluminium, nickel and cobalt, cast or sintered into permanent magnets. Its magnetic output barely changes with temperature: Eclipse says Alnico has the best temperature coefficients of any magnet type, and Arnold quotes a reversible change of 0.02% per degree centigrade. Electron Energy's typical Alnico 5 remanence is 1.28 T, with a Curie temperature of 860 degC and a rated maximum of 525 degC. Its weakness is low coercivity: the typical intrinsic coercivity of cast Alnico 5 is 50.9 kA/m, so it can be demagnetised by its own circuit or by a neighbouring magnet, and it needs a long length-to-diameter ratio. Above about 538 degC the loss of strength is not recovered by remagnetization.\n",
  "best_for": "Magnetic output that stays steady across a wide temperature range, up to 525 to 550 degC (Eclipse and Electron Energy rated maximums)",
  "weakest_at": "Low coercivity (Alnico 5 about 50.9 kA/m, Electron Energy typical) so it demagnetises easily, and irreversible loss above about 538 degC",
  "identity": {
    "formula": "Iron-aluminium-nickel-cobalt alloy (Fe, Al, Ni, Co), with copper and titanium in some grades",
    "designations": [],
    "source": "wikipedia-alnico",
    "where": "Lead section, composition sentence: 8-12% Al, 15-26% Ni, 5-24% Co, up to 6% Cu, up to 1% Ti, rest Fe"
  },
  "tags": {
    "environments": [],
    "stresses": [
      "extreme-heat"
    ],
    "applications": [
      "electronics-and-chips",
      "mechanisms"
    ]
  },
  "properties": [
    {
      "benchmark": "remanence_br",
      "label": "Remanence Br, Alnico 5 (cast)",
      "value": 1.28,
      "bound": "exact",
      "unit": "T",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 5, cast",
        "value_type": "typical, for reference only (not a specification)"
      },
      "method": "Typical value in the Electron Energy Corporation Alnico sell sheet",
      "status": "ground",
      "source": "eec-alnico-sheet",
      "where": "Magnetic Properties of Alnico Magnets, Cast Alnico Magnets, row Alnico 5, column Residual Induction Br (T)",
      "source_detail": {
        "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
        "id": "EECFY21",
        "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "manufacturer sell sheet"
      }
    },
    {
      "benchmark": "remanence_br",
      "label": "Remanence Br, Alnico 8 (cast)",
      "value": 0.82,
      "bound": "exact",
      "unit": "T",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 8, cast",
        "value_type": "typical, for reference only (not a specification)"
      },
      "method": "Typical value in the Electron Energy Corporation Alnico sell sheet",
      "status": "ground",
      "source": "eec-alnico-sheet",
      "where": "Magnetic Properties of Alnico Magnets, Cast Alnico Magnets, row Alnico 8, column Residual Induction Br (T)",
      "source_detail": {
        "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
        "id": "EECFY21",
        "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "manufacturer sell sheet"
      }
    },
    {
      "benchmark": "remanence_br",
      "label": "Remanence Br, Alnico 9 (cast)",
      "value": 1.06,
      "bound": "exact",
      "unit": "T",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 9, cast",
        "value_type": "typical, for reference only (not a specification)"
      },
      "method": "Typical value in the Electron Energy Corporation Alnico sell sheet",
      "status": "ground",
      "source": "eec-alnico-sheet",
      "where": "Magnetic Properties of Alnico Magnets, Cast Alnico Magnets, row Alnico 9, column Residual Induction Br (T)",
      "source_detail": {
        "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
        "id": "EECFY21",
        "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "manufacturer sell sheet"
      }
    },
    {
      "benchmark": "max_energy_product",
      "label": "Maximum energy product (BH)max, Alnico 5 (cast)",
      "value": 43.8,
      "bound": "exact",
      "unit": "kJ/m3",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 5, cast",
        "value_type": "typical, for reference only"
      },
      "method": "Typical value in the Electron Energy Corporation Alnico sell sheet (printed as 5.5 MGOe)",
      "status": "ground",
      "source": "eec-alnico-sheet",
      "where": "Magnetic Properties of Alnico Magnets, Cast Alnico Magnets, row Alnico 5, column (BH)max kJ/m3",
      "source_detail": {
        "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
        "id": "EECFY21",
        "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "manufacturer sell sheet"
      }
    },
    {
      "benchmark": "max_energy_product",
      "label": "Maximum energy product (BH)max, Alnico 9 (cast)",
      "value": 71.6,
      "bound": "exact",
      "unit": "kJ/m3",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 9, cast",
        "value_type": "typical, for reference only"
      },
      "method": "Typical value in the Electron Energy Corporation Alnico sell sheet (printed as 9.0 MGOe)",
      "status": "ground",
      "note": "The Dexter AC900 table prints 10 MGOe for a cast grade of the same name. The two sources differ, so this row uses the Electron Energy figure.",
      "source": "eec-alnico-sheet",
      "where": "Magnetic Properties of Alnico Magnets, Cast Alnico Magnets, row Alnico 9, column (BH)max kJ/m3",
      "source_detail": {
        "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
        "id": "EECFY21",
        "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "manufacturer sell sheet"
      }
    },
    {
      "benchmark": "coercivity_hcj",
      "label": "Intrinsic coercivity Hci, Alnico 5 (cast)",
      "value": 50.9,
      "bound": "exact",
      "unit": "kA/m",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 5, cast",
        "value_type": "typical, for reference only"
      },
      "method": "Typical value in the Electron Energy Corporation Alnico sell sheet (printed as 0.64 kOe)",
      "status": "ground",
      "source": "eec-alnico-sheet",
      "where": "Magnetic Properties of Alnico Magnets, Cast Alnico Magnets, row Alnico 5, column Intrinsic Coercivity iHC (kA/m)",
      "source_detail": {
        "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
        "id": "EECFY21",
        "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "manufacturer sell sheet"
      }
    },
    {
      "benchmark": "coercivity_hcj",
      "label": "Intrinsic coercivity Hci, Alnico 8 (cast)",
      "value": 148.1,
      "bound": "exact",
      "unit": "kA/m",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 8, cast",
        "value_type": "typical, for reference only"
      },
      "method": "Typical value in the Electron Energy Corporation Alnico sell sheet (printed as 1.86 kOe)",
      "status": "ground",
      "source": "eec-alnico-sheet",
      "where": "Magnetic Properties of Alnico Magnets, Cast Alnico Magnets, row Alnico 8, column Intrinsic Coercivity iHC (kA/m)",
      "source_detail": {
        "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
        "id": "EECFY21",
        "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "manufacturer sell sheet"
      }
    },
    {
      "benchmark": "coercivity_hcj",
      "label": "Intrinsic coercivity Hci, Alnico 9 (cast)",
      "value": 119.4,
      "bound": "exact",
      "unit": "kA/m",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 9, cast",
        "value_type": "typical, for reference only"
      },
      "method": "Typical value in the Electron Energy Corporation Alnico sell sheet (printed as 1.50 kOe)",
      "status": "ground",
      "source": "eec-alnico-sheet",
      "where": "Magnetic Properties of Alnico Magnets, Cast Alnico Magnets, row Alnico 9, column Intrinsic Coercivity iHC (kA/m)",
      "source_detail": {
        "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
        "id": "EECFY21",
        "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "manufacturer sell sheet"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature, Alnico 5 (cast)",
      "value": 860,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 5, cast"
      },
      "method": "Value in the Electron Energy Corporation Alnico sell sheet (printed as 1580 degF)",
      "status": "ground",
      "source": "eec-alnico-sheet",
      "where": "Mechanical Properties of Alnico Magnets, Cast Alnico Magnets, row Alnico 5, column Curie Temperature (degC)",
      "source_detail": {
        "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
        "id": "EECFY21",
        "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "manufacturer sell sheet"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature, cast Alnico (Dexter range)",
      "value": 760,
      "value_high": 860,
      "bound": "range",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "material": "cast Alnico, typical range across the Dexter cast grades"
      },
      "method": "Range printed in the Dexter typical physical properties table for cast Alnico",
      "status": "ground",
      "source": "dexter-alnico",
      "where": "Typical Physical Properties, Cast, row Curie Temperature",
      "source_detail": {
        "title": "Alnico Curves and Properties Table (Dexter Magnetic Technologies, V101)",
        "id": "Dexter_Alnico_Curves__Properties_Table.pdf",
        "url": "https://www.dextermag.com/wp-content/uploads/2016/10/Dexter_Alnico_Curves__Properties_Table.pdf",
        "year": 2010,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Maximum working temperature, Alnico 5",
      "value": 525,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 5",
        "note": "maximum recommended temperature; the supplier says the application affects the performance available"
      },
      "method": "Value in the Eclipse Magnetics maximum working temperature table",
      "status": "ground",
      "note": "Electron Energy prints 525 degC for Alnico 5 and 540 degC for Alnico 8 and 9. Eclipse prints 550 degC for Alnico 8 and 9 and is used here.",
      "source": "eclipse-alnico",
      "where": "Max Working Temperature table, row Alnico 5",
      "source_detail": {
        "title": "Technical Data Sheet, Alnico Magnets (Eclipse Magnetics)",
        "id": "eclipsemagnetics_alnico_data_sheet.pdf",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Maximum working temperature, Alnico 8",
      "value": 550,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 8",
        "note": "maximum recommended temperature; the supplier says the application affects the performance available"
      },
      "method": "Value in the Eclipse Magnetics maximum working temperature table",
      "status": "ground",
      "source": "eclipse-alnico",
      "where": "Max Working Temperature table, row Alnico 8",
      "source_detail": {
        "title": "Technical Data Sheet, Alnico Magnets (Eclipse Magnetics)",
        "id": "eclipsemagnetics_alnico_data_sheet.pdf",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Maximum working temperature, Alnico 9",
      "value": 550,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 9",
        "note": "maximum recommended temperature; the supplier says the application affects the performance available"
      },
      "method": "Value in the Eclipse Magnetics maximum working temperature table",
      "status": "ground",
      "source": "eclipse-alnico",
      "where": "Max Working Temperature table, row Alnico 9",
      "source_detail": {
        "title": "Technical Data Sheet, Alnico Magnets (Eclipse Magnetics)",
        "id": "eclipsemagnetics_alnico_data_sheet.pdf",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "temp_coeff_br",
      "label": "Reversible temperature coefficient of Br, Alnico 5 (alpha)",
      "value": -0.02,
      "bound": "exact",
      "unit": "%/degC",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 5, cast and sintered",
        "range": "not printed in the table"
      },
      "method": "Value in the Eclipse Magnetics temperature-coefficient table (alpha, induction)",
      "status": "ground",
      "source": "eclipse-alnico",
      "where": "Temperature coefficients table, Rev. Temp. Coef. of Induction (Br) alpha, entry Alnico 5",
      "source_detail": {
        "title": "Technical Data Sheet, Alnico Magnets (Eclipse Magnetics)",
        "id": "eclipsemagnetics_alnico_data_sheet.pdf",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "temp_coeff_br",
      "label": "Reversible temperature coefficient of Br, Alnico 8 (alpha)",
      "value": -0.025,
      "bound": "exact",
      "unit": "%/degC",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 8, cast and sintered",
        "range": "not printed in the table"
      },
      "method": "Value in the Eclipse Magnetics temperature-coefficient table (alpha, induction)",
      "status": "ground",
      "source": "eclipse-alnico",
      "where": "Temperature coefficients table, Rev. Temp. Coef. of Induction (Br) alpha, entry Alnico 8",
      "source_detail": {
        "title": "Technical Data Sheet, Alnico Magnets (Eclipse Magnetics)",
        "id": "eclipsemagnetics_alnico_data_sheet.pdf",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "temp_coeff_br",
      "label": "Reversible temperature coefficient of Br, Alnico 9 (alpha)",
      "value": -0.025,
      "bound": "exact",
      "unit": "%/degC",
      "scope": "material",
      "conditions": {
        "grade": "Alnico 9, cast and sintered",
        "range": "not printed in the table"
      },
      "method": "Value in the Eclipse Magnetics temperature-coefficient table (alpha, induction)",
      "status": "ground",
      "source": "eclipse-alnico",
      "where": "Temperature coefficients table, Rev. Temp. Coef. of Induction (Br) alpha, entry Alnico 9",
      "source_detail": {
        "title": "Technical Data Sheet, Alnico Magnets (Eclipse Magnetics)",
        "id": "eclipsemagnetics_alnico_data_sheet.pdf",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, cast Alnico (Dexter range)",
      "value": 6.9,
      "value_high": 7.3,
      "bound": "range",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "material": "cast Alnico, typical range"
      },
      "method": "Range printed in the Dexter typical physical properties table for cast Alnico",
      "status": "ground",
      "source": "dexter-alnico",
      "where": "Typical Physical Properties, Cast, row Density (g cm-3)",
      "source_detail": {
        "title": "Alnico Curves and Properties Table (Dexter Magnetic Technologies, V101)",
        "id": "Dexter_Alnico_Curves__Properties_Table.pdf",
        "url": "https://www.dextermag.com/wp-content/uploads/2016/10/Dexter_Alnico_Curves__Properties_Table.pdf",
        "year": 2010,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, Alnico (SDS range)",
      "value": 6.8,
      "value_high": 7.4,
      "bound": "range",
      "unit": "g/cc",
      "scope": "material",
      "conditions": {
        "material": "Alnico 2 to 9 and sub-grades, as stated in the supplier SDS"
      },
      "method": "Range printed in the supplier safety data sheet, physical properties section",
      "status": "ground",
      "source": "allstar-alnico-sds",
      "where": "Section 9.1 Basic Physical and Chemical Properties, row Density",
      "source_detail": {
        "title": "Allstar Magnetics Safety Data Sheet, Alnico 2 to 9 and all sub-grades (Rev 1.0, 08Feb2024)",
        "id": "SDS Alnico, Rev 1.0, 08Feb2024",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/10/Alnico-SDS.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, Alnico (SDS range)",
      "value": 1200,
      "value_high": 1450,
      "bound": "range",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "material": "Alnico family, as stated in the supplier SDS"
      },
      "method": "Range printed in the supplier safety data sheet, physical properties section",
      "status": "ground",
      "source": "allstar-alnico-sds",
      "where": "Section 9.1 Basic Physical and Chemical Properties, row Melting Point",
      "source_detail": {
        "title": "Allstar Magnetics Safety Data Sheet, Alnico 2 to 9 and all sub-grades (Rev 1.0, 08Feb2024)",
        "id": "SDS Alnico, Rev 1.0, 08Feb2024",
        "url": "https://allstarmagnetics.com/wp-content/uploads/2024/10/Alnico-SDS.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "supplier document, linked not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, cast Alnico (Dexter range)",
      "value": 11,
      "value_high": 13,
      "bound": "range",
      "unit": "1e-6 per degC",
      "scope": "material",
      "conditions": {
        "material": "cast Alnico, typical range"
      },
      "method": "Range printed in the Dexter typical physical properties table for cast Alnico",
      "status": "ground",
      "source": "dexter-alnico",
      "where": "Typical Physical Properties, Cast, row Coefficient of Thermal Expansion (x 10-6 degC-1)",
      "source_detail": {
        "title": "Alnico Curves and Properties Table (Dexter Magnetic Technologies, V101)",
        "id": "Dexter_Alnico_Curves__Properties_Table.pdf",
        "url": "https://www.dextermag.com/wp-content/uploads/2016/10/Dexter_Alnico_Curves__Properties_Table.pdf",
        "year": 2010,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, cast Alnico (Dexter range)",
      "value": 45,
      "value_high": 75,
      "bound": "range",
      "unit": "uohm cm",
      "scope": "material",
      "conditions": {
        "material": "cast Alnico, typical range"
      },
      "method": "Range printed in the Dexter typical physical properties table for cast Alnico (printed as uOhm.cm)",
      "status": "ground",
      "source": "dexter-alnico",
      "where": "Typical Physical Properties, Cast, row Electrical Resistivity",
      "source_detail": {
        "title": "Alnico Curves and Properties Table (Dexter Magnetic Technologies, V101)",
        "id": "Dexter_Alnico_Curves__Properties_Table.pdf",
        "url": "https://www.dextermag.com/wp-content/uploads/2016/10/Dexter_Alnico_Curves__Properties_Table.pdf",
        "year": 2010,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "vickers_hardness",
      "label": "Vickers hardness, anisotropic cast Alnico",
      "value": 520,
      "value_high": 700,
      "bound": "range",
      "unit": "Hv",
      "scope": "material",
      "conditions": {
        "material": "anisotropic cast Alnico, typical range"
      },
      "method": "Range printed in the Eclipse Magnetics typical physical characteristics table",
      "status": "ground",
      "source": "eclipse-alnico",
      "where": "Physical Characteristics (Typical), Anisotropic Cast Alnico, row Vickers Hardness",
      "source_detail": {
        "title": "Technical Data Sheet, Alnico Magnets (Eclipse Magnetics)",
        "id": "eclipsemagnetics_alnico_data_sheet.pdf",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "rockwell_c_hardness",
      "label": "Rockwell C hardness, cast Alnico (Dexter range)",
      "value": 45,
      "value_high": 55,
      "bound": "range",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "material": "cast Alnico, typical range"
      },
      "method": "Range printed in the Dexter typical physical properties table for cast Alnico",
      "status": "ground",
      "source": "dexter-alnico",
      "where": "Typical Physical Properties, Cast, row Rockwell C Hardness",
      "source_detail": {
        "title": "Alnico Curves and Properties Table (Dexter Magnetic Technologies, V101)",
        "id": "Dexter_Alnico_Curves__Properties_Table.pdf",
        "url": "https://www.dextermag.com/wp-content/uploads/2016/10/Dexter_Alnico_Curves__Properties_Table.pdf",
        "year": 2010,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "compressive_strength",
      "label": "Compression strength, anisotropic cast Alnico",
      "value": 300,
      "value_high": 400,
      "bound": "range",
      "unit": "N/mm2",
      "scope": "material",
      "conditions": {
        "material": "anisotropic cast Alnico, typical range"
      },
      "method": "Range printed in the Eclipse Magnetics typical physical characteristics table",
      "status": "ground",
      "source": "eclipse-alnico",
      "where": "Physical Characteristics (Typical), Anisotropic Cast Alnico, row Compression Strength",
      "source_detail": {
        "title": "Technical Data Sheet, Alnico Magnets (Eclipse Magnetics)",
        "id": "eclipsemagnetics_alnico_data_sheet.pdf",
        "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf",
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    },
    {
      "benchmark": "flexural_strength",
      "label": "Transverse modulus of rupture, cast Alnico (Dexter range)",
      "value": 0.05,
      "value_high": 0.3,
      "bound": "range",
      "unit": "kN/mm2",
      "scope": "material",
      "conditions": {
        "material": "cast Alnico, typical range",
        "test": "transverse modulus of rupture as printed"
      },
      "method": "Range printed in the Dexter typical physical properties table for cast Alnico",
      "status": "ground",
      "source": "dexter-alnico",
      "where": "Typical Physical Properties, Cast, row Transverse Modulus of Rupture",
      "source_detail": {
        "title": "Alnico Curves and Properties Table (Dexter Magnetic Technologies, V101)",
        "id": "Dexter_Alnico_Curves__Properties_Table.pdf",
        "url": "https://www.dextermag.com/wp-content/uploads/2016/10/Dexter_Alnico_Curves__Properties_Table.pdf",
        "year": 2010,
        "kind": "datasheet",
        "license": "manufacturer datasheet"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Ordinary dry indoor air, as cast or machined",
      "headline": "Alnico has very good to excellent corrosion resistance for most applications.",
      "effect": "Eclipse says Alnico is regarded as having very good to excellent corrosion resistance for most applications. Arnold says Alnico magnets are inherently corrosion resistant.",
      "rating": "low",
      "conditions": {
        "basis": "general statement from two suppliers; no corrosion rate given"
      },
      "source": "eclipse-alnico",
      "where": "Corrosion Resistance box"
    },
    {
      "environment": "Prolonged exposure to water, uncoated",
      "headline": "Iron in the alloy can rust in prolonged water exposure.",
      "effect": "Eclipse says that because iron exists within the Alnico alloy, corrosion may be seen during prolonged exposure to water. Alnico can be coated or painted, but Eclipse notes that this is often only for appearance.",
      "rating": "moderate",
      "conditions": {
        "exposure": "prolonged water exposure, uncoated",
        "duration": "not stated"
      },
      "source": "eclipse-alnico",
      "where": "Corrosion Resistance box"
    },
    {
      "environment": "Strong acids and mineral acids, or corrosive metals in contact with the magnet",
      "headline": "The SDS lists strong and mineral acids as incompatible, and they can make hydrogen.",
      "effect": "The supplier SDS says corrosive substances in contact with metals may produce flammable hydrogen gas. No corrosion rate is given.",
      "rating": "unknown",
      "conditions": {
        "basis": "incompatibility statement, no test"
      },
      "source": "allstar-alnico-sds",
      "where": "Section 10.5 Incompatible Materials and Section 7.2"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Solid Alnico magnet (Allstar SDS, Rev 1.0, 2024): not classified under GHS-US and no label elements apply. The SDS says the solid is not considered flammable, and that the hazards arise in processing: powders, flakes, welding and molten metal.",
        "ghs": [],
        "source": "allstar-alnico-sds",
        "where": "Sections 2.1, 2.2 and 2.3"
      },
      {
        "text": "Dust, chips and ribbons (Allstar SDS): these can be ignited more easily by an ignition source or by improper machining, and finely divided damp dust can ignite spontaneously. Dust clouds suspended in air can be explosive.",
        "ghs": [],
        "source": "allstar-alnico-sds",
        "where": "Sections 5.2 and 7.1"
      },
      {
        "text": "Fumes during processing (Allstar SDS): inhaling fumes may cause lung inflammation, and molten material may release toxic and irritating fumes. Flakes or powder irritate the respiratory tract, eyes and skin.",
        "ghs": [],
        "source": "allstar-alnico-sds",
        "where": "Section 4.2"
      },
      {
        "text": "Cobalt metal (PubChem CID 104730), aggregated notifications from 2768 company reports: signal word Danger. Notified hazards include H317 (above 99.9%), H334 (above 99.9%), H341 (65.8%), H350 (64.5%), H360Fd (61.6%), H302 (65.2%) and H413 (54.9%). This describes the pure metal, not the magnet.",
        "ghs": [
          "H317",
          "H334",
          "H341",
          "H350",
          "H360Fd",
          "H302",
          "H413"
        ],
        "source": "pubchem-cobalt",
        "where": "GHS Classification, aggregated information"
      },
      {
        "text": "Nickel metal (PubChem CID 935), aggregated notifications from 4778 company reports: signal word Danger. Notified hazards include H317 (99.9%), H372 (99.7%), H351 (72.9%), H350 (22.5%), H412 (47.2%), H360F (18%) and H341 (13.5%). This describes the pure metal, not the magnet.",
        "ghs": [
          "H317",
          "H372",
          "H351",
          "H350",
          "H412",
          "H360F",
          "H341"
        ],
        "source": "pubchem-nickel",
        "where": "GHS Classification, aggregated information"
      },
      {
        "text": "Exposure limits printed in the Allstar SDS: cobalt OSHA PEL 0.1 mg/m3, NIOSH REL 0.05 mg/m3, ACGIH TWA 0.02 mg/m3; nickel OSHA PEL 1 mg/m3, NIOSH REL 0.015 mg/m3, ACGIH TWA 1.5 mg/m3. The SDS also lists nickel and cobalt in IARC group 2B.",
        "ghs": [],
        "source": "allstar-alnico-sds",
        "where": "Section 8.1 Control Parameters and Section 11.1 Carcinogenicity"
      }
    ],
    "failure_risks": [
      {
        "mode": "Demagnetisation by heat above the grade limit",
        "trigger": "Heating above about 538 degC (1000 degF)",
        "consequence": "Arnold says that at temperatures above 1000 F (538 C) a metallurgical change reduces magnetic strength rapidly, and that this change will not be recovered by remagnetization. Lower-temperature losses are usually less than 5% and can be recovered by remagnetization.",
        "severity": "high",
        "source": "arnold-alnico",
        "where": "Stability section"
      },
      {
        "mode": "Demagnetisation by the circuit",
        "trigger": "Low length-to-diameter ratio, strong fields from other magnets or electromagnets, or two magnets pushed together in repulsion",
        "consequence": "Eclipse says an L/D ratio of at least 4 or 5 is a rule-of-thumb guide, that external magnets and electromagnets can demagnetise it, and that pushing two Alnico magnets in repulsion can weaken their output. The working point must stay above the knee of the intrinsic curve.",
        "severity": "moderate",
        "source": "eclipse-alnico",
        "where": "Additional Information"
      },
      {
        "mode": "Rust in water",
        "trigger": "Prolonged exposure to water with an uncoated surface",
        "consequence": "Corrosion may be seen, because the alloy contains iron. Coating or painting is an option.",
        "severity": "low",
        "source": "eclipse-alnico",
        "where": "Corrosion Resistance box"
      },
      {
        "mode": "Chips and slivers",
        "trigger": "Cutting, grinding or impact",
        "consequence": "Slivers may be generated, which could cause mechanical irritation or injure the eye.",
        "severity": "moderate",
        "source": "allstar-alnico-sds",
        "where": "Section 4.2 Symptoms after eye contact"
      },
      {
        "mode": "Dust ignition or dust explosion",
        "trigger": "Fine dust or powder, damp finely divided dust, or dust deposits in air",
        "consequence": "Dust can ignite, and dust clouds in air can be explosive. The SDS advises keeping dust off surfaces and removing ignition sources.",
        "severity": "moderate",
        "source": "allstar-alnico-sds",
        "where": "Sections 5.2 and 7.1"
      }
    ],
    "side_effects": [
      {
        "text": "Molten Alnico can release toxic and irritating fumes during melting or casting.",
        "affects": "Foundry and processing operators",
        "source": "allstar-alnico-sds",
        "where": "Section 4.2"
      }
    ],
    "handling": [
      {
        "text": "Avoid creating or spreading dust. Clean up by sweeping or shovelling into a suitable container. A vacuum must have a HEPA filter, and only non-sparking tools and explosion-proof equipment should be used during clean-up.",
        "source": "allstar-alnico-sds",
        "where": "Sections 6.3 and 7.1"
      },
      {
        "text": "Store in a dry, cool place away from strong acids and mineral acids.",
        "source": "allstar-alnico-sds",
        "where": "Section 7.2"
      },
      {
        "text": "Wear eye protection. Safety glasses are advised during metal processing.",
        "source": "allstar-alnico-sds",
        "where": "Sections 6.1.1 and 8.2"
      },
      {
        "text": "Handle with care. Eclipse notes that pushing two Alnico magnets together in repulsion can weaken their output, and that careful handling restores it quickly.",
        "source": "eclipse-alnico",
        "where": "Additional Information"
      }
    ],
    "mitigations": [
      {
        "text": "Use a length-to-diameter ratio of at least 4 or 5 to resist demagnetisation.",
        "source": "eclipse-alnico",
        "where": "Additional Information"
      },
      {
        "text": "Alnico 8 is recommended for applications exposed to strong demagnetizing fields, or where space dictates a short magnetic length.",
        "source": "arnold-alnico",
        "where": "Design Considerations and Grade sections"
      },
      {
        "text": "Alnico can be remagnetised (Eclipse). The loss from heating above about 538 degC is not recovered by remagnetization (Arnold).",
        "source": "eclipse-alnico",
        "where": "Additional Information; Arnold Stability section"
      }
    ]
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Traveling wave tubes and electron tubes",
      "example": "Electron Energy lists Traveling Wave Tubes (TWTs) and Electron Tubes among its Alnico application types, alongside high thermal stability.",
      "source": "eec-alnico-sheet",
      "where": "Features and Application Types list"
    },
    {
      "application": "mechanisms",
      "device": "Generators and magnetic pump couplings",
      "example": "Electron Energy lists Generators and Magnetic Pump Couplings as application types. Eclipse notes that rotating machines and generators using Alnico need careful design, because the air gap varies during rotation.",
      "source": "eclipse-alnico",
      "where": "Additional Information; Electron Energy Application Types list"
    },
    {
      "application": "electronics-and-chips",
      "device": "Automotive, aerospace and military sensors",
      "example": "Electron Energy lists automotive, aerospace and military sensors as an Alnico application type.",
      "source": "eec-alnico-sheet",
      "where": "Application Types list"
    }
  ],
  "supply": [
    {
      "subject": "Cobalt",
      "abundance": "Cobalt is 5 to 24% of the Alnico alloy by weight (Allstar SDS). Cobalt is a constituent of the alloy at these levels.",
      "producers": [
        {
          "country": "Congo (Kinshasa)",
          "share_percent": 73,
          "year": 2025
        },
        {
          "country": "Indonesia",
          "share_percent": 14,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals: Cobalt, used in batteries and metal alloys used in extreme temperatures",
          "listed": true
        },
        {
          "list": "EU critical raw materials list, cobalt entry on the European Commission page",
          "listed": true
        }
      ],
      "recycling": "USGS: in 2025 the cobalt content of purchased scrap represented 25% of estimated cobalt consumption.",
      "substitutes": [
        "USGS: potential substitutes in magnets include barium or strontium ferrites, neodymium-iron-boron alloys, or nickel-iron alloys. Substitution could lower product performance or raise cost."
      ],
      "source": "usgs-mcs2026-cobalt",
      "where": "Events, Trends, and Issues (Congo share and Indonesia share, printed in text); Recycling; Substitutes"
    },
    {
      "subject": "Nickel",
      "abundance": "Nickel is 14 to 21% of the Alnico alloy by weight (Allstar SDS).",
      "producers": [
        {
          "country": "Indonesia",
          "share_percent": 66.7,
          "year": 2025
        },
        {
          "country": "Philippines",
          "share_percent": 6.9,
          "year": 2025
        },
        {
          "country": "Russia",
          "share_percent": 5.1,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals: Nickel, used to make high-strength steel and rechargeable batteries",
          "listed": true
        },
        {
          "list": "EU list: nickel is a strategic raw material but does not meet the critical raw material thresholds (European Commission page)",
          "listed": true
        }
      ],
      "recycling": "USGS: most secondary nickel was in the form of nickel content of stainless-steel scrap.",
      "substitutes": [],
      "source": "usgs-mcs2026-nickel",
      "where": "World Mine Production and Reserves table, 2025e; shares are Space Mushroom computations (Indonesia 2,600,000 of 3,900,000 t; Philippines 270,000 t; Russia 200,000 t)"
    },
    {
      "subject": "Aluminium",
      "abundance": "Aluminium is 8 to 12% of the Alnico alloy by weight (Allstar SDS).",
      "producers": [
        {
          "country": "China",
          "share_percent": 60.8,
          "year": 2025
        },
        {
          "country": "Russia",
          "share_percent": 5.3,
          "year": 2025
        },
        {
          "country": "Canada",
          "share_percent": 4.5,
          "year": 2025
        },
        {
          "country": "United Arab Emirates",
          "share_percent": 3.6,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals: Aluminum, used in almost all sectors of the economy",
          "listed": true
        },
        {
          "list": "EU critical raw materials list: aluminium and bauxite merged, European Commission page",
          "listed": true
        }
      ],
      "recycling": "USGS: about 3.6 million tons of aluminum was recovered from purchased scrap in the United States in 2025.",
      "substitutes": [],
      "source": "usgs-mcs2026-aluminum",
      "where": "World Smelter Production table, 2025e (China 45,000 of 74,000 kt; Russia 3,900; Canada 3,300; UAE 2,700); shares are Space Mushroom computations; Recycling"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Electron Energy Corporation Alnico magnets sell sheet (EECFY21)",
      "type": "datasheet",
      "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
      "year": 2021
    },
    {
      "title": "Eclipse Magnetics Alnico technical data sheet",
      "type": "datasheet",
      "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf"
    },
    {
      "title": "Dexter Magnetic Technologies Alnico curves and properties table (V101)",
      "type": "datasheet",
      "url": "https://www.dextermag.com/wp-content/uploads/2016/10/Dexter_Alnico_Curves__Properties_Table.pdf",
      "year": 2010
    },
    {
      "title": "Allstar Magnetics SDS, Alnico 2 to 9 and all sub-grades, Rev 1.0 (08Feb2024)",
      "type": "sds",
      "url": "https://allstarmagnetics.com/wp-content/uploads/2024/10/Alnico-SDS.pdf",
      "year": 2024
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026, Cobalt",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026, Nickel",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026, Aluminum",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf",
      "year": 2026
    },
    {
      "title": "PubChem compound records: cobalt (CID 104730) and nickel (CID 935), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/104730",
      "year": 2026
    }
  ],
  "gaps": [
    "No flight, vacuum, thermal-cycling or space-qualification source was found for Alnico. Electron Energy lists TWTs as an application but gives no space data.",
    "Radiation tolerance of Alnico (gamma, electron, neutron or proton dose at which flux is lost) was not found in an opened source.",
    "Normal coercivity Hcb for Alnico 5, 8 and 9 was not added: Dexter prints Hc values for AC500, AC800 and AC900, but it was not included to keep the grades consistent with the Electron Energy values.",
    "Sign and size of the coercivity temperature coefficient (beta) were not used: Eclipse prints +0.01 %/degC for Alnico 5, Dexter prints -0.02 %/degC (AC500) and Electron Energy prints -0.015 %/degC near (BH)max. The three sources disagree.",
    "Tensile strength was not used: the Electron Energy table gives kPa and kpsi columns that do not agree, and the Eclipse range was printed without a grade.",
    "Thermal conductivity was not found in an opened source.",
    "A quantified corrosion rate or salt-spray result for Alnico was not found in an opened source.",
    "No safety data sheet for the alloy gave a GHS classification. The PubChem records describe the pure metals cobalt and nickel, not the magnet alloy.",
    "Atomic weights are PubChem molecular-weight values printed to two decimals (Fe 55.84, Al 26.981538, Co 58.93319, Ni 58.693, Cu 63.55), not IUPAC table values.",
    "Crystal structure, CAS number and UNS or other designation codes for Alnico were not taken from a source we opened.",
    "Shares for nickel, aluminium and cobalt are computed from USGS tables (nickel and aluminium) or printed in text (cobalt). Iron and titanium supply were not read.",
    "Property names remanence_br, coercivity_hcj, temp_coeff_br, rockwell_c_hardness and compressive_strength are not in spores/property-canon.yaml; they follow the NdFeB profile naming.",
    "Electron Energy max operating temperatures (540 degC for Alnico 8 and 9) differ from Eclipse (550 degC); both are noted, Eclipse is used."
  ],
  "story": {
    "why": "Alnico is a cast or sintered alloy of iron, aluminium, nickel and cobalt, first developed in 1931 (Wikipedia). Its magnetic output hardly changes with temperature, which is its main advantage. Eclipse says Alnico has the best temperature coefficients of any magnet type and is the best choice for extremely high-temperature work. Its Curie temperature is 860 degC for cast Alnico 5 (Electron Energy) and it is rated to 525 to 550 degC. The cost of that stability is low coercivity: a cast Alnico 5 magnet has an intrinsic coercivity of only 50.9 kA/m, so the magnet must be long and the circuit well designed.",
    "uses": [
      {
        "where": "Traveling wave tubes and electron tubes",
        "line": "Electron Energy lists TWTs and electron tubes among its Alnico application types, alongside high thermal stability."
      },
      {
        "where": "Generators and magnetic pump couplings",
        "line": "Electron Energy lists generators and magnetic pump couplings as applications. Eclipse adds that rotating machines using Alnico need careful design because the air gap varies during rotation."
      },
      {
        "where": "Sensors",
        "line": "Electron Energy lists automotive, aerospace and military sensors as an application type."
      }
    ],
    "can_do": [
      {
        "label": "Stable output with heat",
        "line": "Arnold quotes a reversible temperature coefficient of 0.02% per degree centigrade, which it calls the lowest of any standard commercial magnet. Eclipse gives -0.02 %/degC for Alnico 5 and -0.025 %/degC for Alnico 8 and 9.",
        "scope": "material",
        "value": "0.02% per degC"
      },
      {
        "label": "Working heat",
        "line": "Eclipse rates Alnico 5 to 525 degC and Alnico 8 and 9 to 550 degC. Electron Energy rates the grades to 540 degC.",
        "scope": "material",
        "value": "Rated 525 to 550 degC"
      },
      {
        "label": "Remanence",
        "line": "Electron Energy gives a typical remanence of 1.28 T for cast Alnico 5, 0.82 T for cast Alnico 8 and 1.06 T for cast Alnico 9.",
        "scope": "material",
        "value": "1.28 T (Alnico 5)"
      },
      {
        "label": "Hardness",
        "line": "Eclipse gives a Vickers hardness of 520 to 700 Hv for anisotropic cast Alnico, and Dexter gives 45 to 55 HRC for cast grades.",
        "scope": "material",
        "value": "520 to 700 Hv"
      }
    ],
    "compare": "Alnico trades strength for stability. Its remanence and energy product are modest, and its coercivity is low for the grades listed. Its output changes little with heat and its Curie temperature is high, which makes it suited to hot environments. USGS lists neodymium-iron-boron alloys among the potential substitutes for cobalt in magnets, and Wikipedia says rare-earth magnets are replacing Alnico in many of its applications.",
    "compare_rows": [
      {
        "label": "Remanence (Alnico 5)",
        "benchmark": "remanence_br",
        "scope": "material"
      },
      {
        "label": "Maximum energy product (Alnico 9)",
        "benchmark": "max_energy_product",
        "scope": "material"
      },
      {
        "label": "Curie temperature (cast Alnico 5)",
        "benchmark": "curie_temperature",
        "scope": "material"
      }
    ],
    "handling": [
      "Avoid dust. Clean up mechanically, using a HEPA-filtered vacuum where a vacuum is needed.",
      "Keep it dry, cool and away from strong and mineral acids.",
      "Use an L/D ratio of 4 or 5 or more, and keep external magnets and fields away from the working magnet."
    ],
    "good_for": [
      "Output that must stay steady across a wide temperature range, such as sensors and generators in hot environments.",
      "Electron tubes and travelling wave tubes, where Electron Energy lists Alnico for high-temperature stability."
    ],
    "watch_out": [
      "Low coercivity: an Alnico 5 magnet has only 50.9 kA/m intrinsic coercivity (Electron Energy typical).",
      "Irreversible loss above about 538 degC (Arnold).",
      "Rust in prolonged water exposure if uncoated (Eclipse).",
      "Concentrated supply: Congo (Kinshasa) mined an estimated 73% of world cobalt and Indonesia 66.7% of world nickel (USGS; the nickel share is computed from the table)."
    ],
    "verdict": "Alnico is the high-temperature choice among the magnet alloys covered here. It gives up coercivity to get a very small change of output with heat, and it needs a long, well-designed magnetic circuit. The sourced data show good thermal stability and modest magnetic output, and no flight or space-qualification data were found.",
    "recipe": {
      "line": "Alnico is an iron-based alloy of aluminium, nickel and cobalt, named after the initials of those elements. Typical grades carry 8 to 12% aluminium, 15 to 26% nickel, 5 to 24% cobalt, up to 6% copper and up to 1% titanium, with iron as the balance. The supplier SDS gives a narrower nickel range (14 to 21%) and lists iron at 40 to 70%. Eclipse says Alnico can be produced by casting or sintering, and that casting is often used for near-net-shape magnets.",
      "parts": [
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "Largest part of the alloy by weight (SDS). Iron is why uncoated Alnico can rust in prolonged water exposure (Eclipse).",
          "source": "pubchem-iron"
        },
        {
          "name": "Aluminium",
          "symbol": "Al",
          "role": "One of the three main additions named in the alloy's name (Wikipedia). Its share is 8 to 12% (SDS).",
          "source": "pubchem-aluminum"
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "A main addition: 15 to 26% in the Wikipedia range and 14 to 21% in the SDS.",
          "source": "pubchem-nickel"
        },
        {
          "name": "Cobalt",
          "symbol": "Co",
          "role": "A main addition at 5 to 24% (SDS and Wikipedia). USGS notes that cobalt is used in metal alloys used at extreme temperatures.",
          "source": "pubchem-cobalt"
        },
        {
          "name": "Copper",
          "symbol": "Cu",
          "role": "Present in some grades, up to 6% (Wikipedia), and 0.1 to 6% in the SDS.",
          "source": "pubchem-copper"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The supplier SDS does not classify the solid magnet under GHS-US. The hazards come from dust, fumes and chips during processing.",
        "points": [
          {
            "label": "Dust and fumes",
            "line": "Do not breathe dust or fumes. Molten material and metal processing give off irritating fumes, and nickel and cobalt compounds are on the IARC 2B list in the SDS."
          },
          {
            "label": "Chips",
            "line": "Slivers can be produced by cutting or grinding, and they can injure the eye. Wear eye protection."
          }
        ],
        "gap": "No GHS classification for the alloy as a whole; the PubChem entries describe the pure metals.",
        "level": 1,
        "verdict": "No safety classification for the solid"
      },
      {
        "title": "If it fails",
        "lead": "Heating above about 538 degC causes an irreversible loss, and low coercivity makes it sensitive to its circuit.",
        "points": [
          {
            "label": "Heat",
            "line": "Above about 538 degC (1000 degF) Arnold says magnetic strength falls rapidly and is not recovered by remagnetization."
          },
          {
            "label": "Circuit",
            "line": "Eclipse says a low L/D ratio, strong external fields and magnets pushed together in repulsion can all weaken Alnico."
          }
        ],
        "level": 3,
        "verdict": "Heat and poor circuit design demagnetise it"
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Dust",
            "line": "Keep dust off surfaces and clean up mechanically. Fine dust can ignite and dust clouds can be explosive."
          },
          {
            "label": "Storage",
            "line": "Store dry and cool, away from strong and mineral acids, which can produce flammable hydrogen."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-16",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 25,
    "unreachable": 0,
    "caveats": 4,
    "note": "Written by an AI assistant from sources opened in this run: the Electron Energy sell sheet, the Eclipse data sheet, the Dexter table, the Allstar SDS, the USGS 2026 cobalt, nickel and aluminium summaries, the PubChem cobalt and nickel records, and the Arnold product page. The Wikipedia page was read for composition and history only. Values were copied as printed, and computed shares are labelled in where. Three sources disagree on some values, and those rows carry notes."
  },
  "sources": {
    "eec-alnico-sheet": {
      "title": "Alnico Magnets, Electron Energy Corporation sell sheet (EECFY21)",
      "id": "EECFY21",
      "url": "https://www.electronenergy.com/hubfs/Rebrand%20-%20Sell%20Sheets/EECFY21_Alnico%20Sell%20Sheet.pdf",
      "year": 2021,
      "kind": "datasheet",
      "license": "manufacturer sell sheet"
    },
    "eclipse-alnico": {
      "title": "Technical Data Sheet, Alnico Magnets (Eclipse Magnetics)",
      "id": "eclipsemagnetics_alnico_data_sheet.pdf",
      "url": "https://www.eclipsemagnetics.com/site/assets/files/22210/eclipsemagnetics_alnico_data_sheet.pdf",
      "kind": "datasheet",
      "license": "manufacturer datasheet"
    },
    "dexter-alnico": {
      "title": "Alnico Curves and Properties Table (Dexter Magnetic Technologies, V101)",
      "id": "Dexter_Alnico_Curves__Properties_Table.pdf",
      "url": "https://www.dextermag.com/wp-content/uploads/2016/10/Dexter_Alnico_Curves__Properties_Table.pdf",
      "year": 2010,
      "kind": "datasheet",
      "license": "manufacturer datasheet"
    },
    "arnold-alnico": {
      "title": "Alnico magnets (Arnold Magnetic Technologies product page)",
      "url": "https://www.arnoldmagnetics.com/products/alnico-magnets",
      "kind": "web",
      "license": "supplier web page"
    },
    "wikipedia-alnico": {
      "title": "Alnico (Wikipedia)",
      "url": "https://en.wikipedia.org/wiki/Alnico",
      "kind": "web",
      "license": "CC BY-SA"
    },
    "allstar-alnico-sds": {
      "title": "Allstar Magnetics Safety Data Sheet, Alnico 2 to 9 and all sub-grades (Rev 1.0, 08Feb2024)",
      "id": "SDS Alnico, Rev 1.0, 08Feb2024",
      "url": "https://allstarmagnetics.com/wp-content/uploads/2024/10/Alnico-SDS.pdf",
      "year": 2024,
      "kind": "datasheet",
      "license": "supplier document, linked not reproduced"
    },
    "usgs-mcs2026-cobalt": {
      "title": "Mineral Commodity Summaries 2026, Cobalt",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-mcs2026-nickel": {
      "title": "Mineral Commodity Summaries 2026, Nickel",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-mcs2026-aluminum": {
      "title": "Mineral Commodity Summaries 2026, Aluminum",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-crit-2025": {
      "title": "About the 2025 List of Critical Minerals (USGS, final list of 60 minerals, 6 Nov 2025)",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "kind": "web",
      "license": "public domain (USGS)"
    },
    "eu-crm-page": {
      "title": "Critical raw materials (European Commission)",
      "url": "https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en",
      "kind": "web",
      "license": "EC web page"
    },
    "pubchem-cobalt": {
      "title": "PubChem compound CID 104730, cobalt: GHS classification and molecular weight",
      "id": "CID 104730",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/104730",
      "kind": "database"
    },
    "pubchem-nickel": {
      "title": "PubChem compound CID 935, nickel: GHS classification and molecular weight",
      "id": "CID 935",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/935",
      "kind": "database"
    },
    "pubchem-iron": {
      "title": "PubChem compound CID 23925, iron: molecular weight",
      "id": "CID 23925",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23925",
      "kind": "database"
    },
    "pubchem-aluminum": {
      "title": "PubChem compound CID 5359268, aluminum: molecular weight",
      "id": "CID 5359268",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/5359268",
      "kind": "database"
    },
    "pubchem-copper": {
      "title": "PubChem compound CID 23978, copper: molecular weight",
      "id": "CID 23978",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23978",
      "kind": "database"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/alnico/"
}