{
  "spore": "profile",
  "id": "mu-metal",
  "spore_version": "0.2",
  "family": "magnet-and-superconducting-alloys",
  "name": "Mu-metal",
  "abbreviation": "Ni-Fe-Mo",
  "role": "magnetic shield",
  "category": "metals",
  "type": "magnet-alloys",
  "summary": "Mu-metal is a soft nickel-iron-molybdenum alloy, nominally 80 % Ni and 5 % Mo (ASTM A753 Alloy 4), used to shield sensitive electronics from static and low-frequency magnetic fields. The Magnetic Shield Corporation sheet gives a DC permeability of at least 400,000 at 0.005 Oe, an AC permeability of at least 75,000 at 60 Hz and 0.4 A/m, a saturation induction of 0.75 T and a density of 8.7 g/cm3. Its strength is modest: a supplier page gives 530 MPa tensile and 160 MPa yield in the final annealed state.\n",
  "best_for": "Shielding sensitive electronics from static and low-frequency fields: DC permeability of at least 400,000 and AC permeability of at least 75,000 at 60 Hz in the MuMETAL sheet datasheet",
  "weakest_at": "Strength and weight: 160 MPa yield in the final annealed state and 8.7 g/cm3 density, and the permeability falls after shock or plastic strain, which needs a re-anneal to recover",
  "identity": {
    "formula": "Nickel-iron-molybdenum soft magnetic alloy, nominal 80 % Ni and 5 % Mo by weight, balance Fe, with Mn 0.50 % and Si 0.15 % nominal (CarTech HyMu 800 type analysis)",
    "designations": [
      {
        "system": "UNS",
        "code": "N14080",
        "source": "msc-mumetal",
        "where": "Specifications paragraph: meets ASTM-A-753 Alloy 4, UNS N14080"
      },
      {
        "system": "ASTM",
        "code": "A753",
        "note": "Alloy 4",
        "source": "carpenter-hymu800",
        "where": "Other Information, Applicable Specifications: ASTM A753 Alloy 4"
      },
      {
        "system": "DIN",
        "code": "17745",
        "source": "msc-mumetal",
        "where": "Specifications paragraph: DIN 17745"
      },
      {
        "system": "JIS",
        "code": "C 2531",
        "source": "matthey-permimphy",
        "where": "International Standards table: JIS C 2531, row N14080 Type 4"
      },
      {
        "system": "Trade name",
        "code": "MuMETAL",
        "source": "msc-mumetal",
        "where": "Footer and product title: MuMETAL registered trademark of Magnetic Shield Corporation"
      },
      {
        "system": "Trade name",
        "code": "Mumetall",
        "source": "wikipedia-mumetal",
        "where": "Lead section: trade names such as MuMETAL, Mumetall and Mumetal2"
      },
      {
        "system": "Trade name",
        "code": "Permimphy",
        "source": "matthey-permimphy",
        "where": "Title and main technical properties: Permimphy N14080 type 4 alloy"
      }
    ],
    "source": "carpenter-hymu800",
    "where": "Type Analysis table: Carbon 0.01 %, Manganese 0.50 %, Silicon 0.15 %, Nickel 80.00 %, Molybdenum 5.00 %, Iron balance"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "electronics-and-chips"
    ]
  },
  "properties": [
    {
      "benchmark": "saturation_induction",
      "label": "Saturation induction, stress annealed sheet",
      "value": 0.75,
      "bound": "exact",
      "unit": "T",
      "scope": "material",
      "conditions": {
        "grade": "MuMETAL, 80 Ni 5 Mo, stress annealed sheet",
        "temperature": "not stated",
        "unit_in_source": "7,500 G (0.75 T)"
      },
      "method": "Typical value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "msc-mumetal",
      "where": "Physical Properties table, row Saturation Induction (Bs)",
      "source_detail": {
        "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
        "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "saturation_induction",
      "label": "Saturation induction at 20 °C",
      "value": 0.8,
      "bound": "exact",
      "unit": "T",
      "scope": "material",
      "conditions": {
        "grade": "Permimphy N14080 type 4 (80 % Ni, 5 % Mo)",
        "temperature": "20 °C"
      },
      "method": "Typical value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "matthey-permimphy",
      "where": "Physical properties table, row Saturation induction at 20ºC",
      "source_detail": {
        "title": "Lamineries Matthey, Mumetal Permimphy N14080 type 4 datasheet",
        "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "permeability_dc_min",
      "label": "DC permeability at 0.005 Oe, minimum",
      "value": 400000,
      "bound": "lower",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "grade": "MuMETAL, 80 Ni 5 Mo",
        "field": "0.005 Oe (0.4 A/m)",
        "sample": "stamped rings of 0.35 mm sheet after perfection annealing"
      },
      "method": "Minimum value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "msc-mumetal",
      "where": "DC Magnetic Properties, row Permeability at 0.005 Oe",
      "source_detail": {
        "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
        "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "permeability_ac_60hz",
      "label": "AC permeability at 60 Hz and 0.4 A/m, minimum",
      "value": 75000,
      "bound": "lower",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "grade": "MuMETAL, 80 Ni 5 Mo",
        "frequency": "60 Hz",
        "field": "0.4 A/m",
        "sample": "stamped rings of 0.35 mm sheet after perfection annealing"
      },
      "method": "Minimum value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "msc-mumetal",
      "where": "AC (60 Hz) Magnetic Properties, row Permeability at 0.4 A/m",
      "source_detail": {
        "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
        "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "permeability_dc",
      "label": "DC permeability at 5 mOe, typical, 1.00 mm strip",
      "value": 470000,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "grade": "Permimphy N14080 type 4",
        "thickness": "1.00 mm",
        "field": "5 mOe (0.4 A/m)",
        "treatment": "ring samples annealed at 1170 °C in dry pure hydrogen"
      },
      "method": "Typical value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "matthey-permimphy",
      "where": "Magnetic properties table, DC row, thickness 1.00 - 0.04 mm",
      "source_detail": {
        "title": "Lamineries Matthey, Mumetal Permimphy N14080 type 4 datasheet",
        "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "permeability_dc",
      "label": "DC permeability at 5 mOe, typical, 0.34 mm strip",
      "value": 520000,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "grade": "Permimphy N14080 type 4",
        "thickness": "0.34 mm",
        "field": "5 mOe (0.4 A/m)",
        "treatment": "ring samples annealed at 1170 °C in dry pure hydrogen"
      },
      "method": "Typical value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "matthey-permimphy",
      "where": "Magnetic properties table, DC row, thickness 0.34 - 0.0134 mm",
      "source_detail": {
        "title": "Lamineries Matthey, Mumetal Permimphy N14080 type 4 datasheet",
        "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "permeability_max",
      "label": "Maximum DC permeability after final heat treatment",
      "value": 350000,
      "value_high": 500000,
      "bound": "range",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "grade": "Mu-metal, final heat treatment in dry hydrogen",
        "condition": "typical DC magnetic properties after final heat treatment"
      },
      "method": "Range printed on a manufacturer web page",
      "status": "ground",
      "source": "msc-mumetal-web",
      "where": "Typical Final Annealed Properties block, Typical Magnetic Properties (DC), row Permeability Mumax",
      "source_detail": {
        "title": "Magnetic Shields Limited, Mu Metal specifications page (mumetal.co.uk)",
        "url": "https://mumetal.co.uk/?p=100",
        "kind": "web",
        "license": "Manufacturer web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "coercive_force",
      "label": "Coercive force after final heat treatment",
      "value": 0.6,
      "bound": "exact",
      "unit": "A/m",
      "scope": "material",
      "conditions": {
        "condition": "typical DC magnetic properties after final heat treatment"
      },
      "method": "Typical value printed on a manufacturer web page",
      "status": "ground",
      "source": "msc-mumetal-web",
      "where": "Typical Magnetic Properties (DC) block, row Coercive Force",
      "source_detail": {
        "title": "Magnetic Shields Limited, Mu Metal specifications page (mumetal.co.uk)",
        "url": "https://mumetal.co.uk/?p=100",
        "kind": "web",
        "license": "Manufacturer web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature",
      "value": 420,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "unit_in_source": "788 °F"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "msc-mumetal",
      "where": "Physical Properties table, row Curie Temperature",
      "source_detail": {
        "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
        "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, stress annealed sheet",
      "value": 8.7,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "MuMETAL, 80 Ni 5 Mo",
        "unit_in_source": "0.316 lb/in3"
      },
      "method": "Typical value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "msc-mumetal",
      "where": "Physical Properties table, row Density",
      "source_detail": {
        "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
        "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, 80 Ni 5 Mo alloy (HyMu 800)",
      "value": 0.316,
      "bound": "exact",
      "unit": "lb/in3",
      "scope": "material",
      "conditions": {
        "grade": "HyMu 800, 80 Ni 5 Mo",
        "temperature": "not stated"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "carpenter-hymu800",
      "where": "Physical Properties, row Density",
      "source_detail": {
        "title": "CarTech HyMu 800 alloy data sheet, Carpenter Technology",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/HyMu%20800.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet, typical values (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting temperature",
      "value": 1450,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "Permimphy N14080 type 4"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "matthey-permimphy",
      "where": "Physical properties table, row Melting point",
      "source_detail": {
        "title": "Lamineries Matthey, Mumetal Permimphy N14080 type 4 datasheet",
        "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, stress annealed sheet",
      "value": 19,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "grade": "MuMETAL, 80 Ni 5 Mo",
        "temperature": "not stated"
      },
      "method": "Typical value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "msc-mumetal",
      "where": "Physical Properties table, row Thermal Conductivity",
      "source_detail": {
        "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
        "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, 80 Ni 5 Mo alloy (HyMu 800)",
      "value": 240,
      "bound": "exact",
      "unit": "BTU-in/hr/ft2/°F",
      "scope": "material",
      "conditions": {
        "grade": "HyMu 800, 80 Ni 5 Mo",
        "temperature": "not stated"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "carpenter-hymu800",
      "where": "Physical Properties, row Thermal Conductivity",
      "source_detail": {
        "title": "CarTech HyMu 800 alloy data sheet, Carpenter Technology",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/HyMu%20800.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet, typical values (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Thermal expansion coefficient, stress annealed sheet",
      "value": 12,
      "bound": "exact",
      "unit": "10-6/K",
      "scope": "material",
      "conditions": {
        "grade": "MuMETAL, 80 Ni 5 Mo",
        "temperature": "not stated"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "msc-mumetal",
      "where": "Physical Properties table, row Thermal Expansion",
      "source_detail": {
        "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
        "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of thermal expansion, -90 to 400 °F",
      "value": 7.2,
      "bound": "exact",
      "unit": "10-6 in/in/°F",
      "scope": "material",
      "conditions": {
        "grade": "HyMu 800, 80 Ni 5 Mo",
        "temperature": "-90 to 400 °F"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "carpenter-hymu800",
      "where": "Physical Properties, row Mean CTE (-90 to 400°F)",
      "source_detail": {
        "title": "CarTech HyMu 800 alloy data sheet, Carpenter Technology",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/HyMu%20800.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet, typical values (cited, not reproduced)"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat",
      "value": 460,
      "bound": "exact",
      "unit": "J/(kg·K)",
      "scope": "material",
      "conditions": {
        "grade": "MuMETAL, 80 Ni 5 Mo",
        "temperature": "not stated"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "msc-mumetal",
      "where": "Physical Properties table, row Specific Heat",
      "source_detail": {
        "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
        "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, stress annealed sheet",
      "value": 60,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "grade": "MuMETAL, 80 Ni 5 Mo",
        "temperature": "not stated"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "msc-mumetal",
      "where": "Physical Properties table, row Electrical Resistivity",
      "source_detail": {
        "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
        "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity at 70 °F, 80 Ni 5 Mo alloy (HyMu 800)",
      "value": 370,
      "value_high": 380,
      "bound": "range",
      "unit": "ohm-cir-mil/ft",
      "scope": "material",
      "conditions": {
        "grade": "HyMu 800, 80 Ni 5 Mo",
        "temperature": "70 °F"
      },
      "method": "Range printed in a manufacturer datasheet",
      "status": "ground",
      "source": "carpenter-hymu800",
      "where": "Physical Properties, row Electrical Resistivity (70°F)",
      "source_detail": {
        "title": "CarTech HyMu 800 alloy data sheet, Carpenter Technology",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/HyMu%20800.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet, typical values (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, Permimphy strip",
      "value": 190,
      "value_high": 221,
      "bound": "range",
      "unit": "kN/mm2",
      "scope": "material",
      "conditions": {
        "grade": "Permimphy N14080 type 4",
        "temperature": "not stated"
      },
      "method": "Range printed in a manufacturer datasheet",
      "status": "ground",
      "source": "matthey-permimphy",
      "where": "Physical properties table, row Modulus of elasticity",
      "source_detail": {
        "title": "Lamineries Matthey, Mumetal Permimphy N14080 type 4 datasheet",
        "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, soft annealed temper R500",
      "value": 500,
      "value_high": 700,
      "bound": "range",
      "unit": "N/mm2",
      "scope": "material",
      "conditions": {
        "grade": "Permimphy N14080 type 4",
        "temper": "R500 soft annealed",
        "product_form": "strip"
      },
      "method": "Range printed in a manufacturer datasheet",
      "status": "ground",
      "source": "matthey-permimphy",
      "where": "Mechanical properties of strips table, row R500 soft annealed, column Rm",
      "source_detail": {
        "title": "Lamineries Matthey, Mumetal Permimphy N14080 type 4 datasheet",
        "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength Rp0.2, soft annealed temper R500",
      "value": 200,
      "value_high": 450,
      "bound": "range",
      "unit": "N/mm2",
      "scope": "material",
      "conditions": {
        "grade": "Permimphy N14080 type 4",
        "temper": "R500 soft annealed",
        "measure": "Rp0.2",
        "product_form": "strip"
      },
      "method": "Range printed in a manufacturer datasheet",
      "status": "ground",
      "source": "matthey-permimphy",
      "where": "Mechanical properties of strips table, row R500 soft annealed, column Rp0.2",
      "source_detail": {
        "title": "Lamineries Matthey, Mumetal Permimphy N14080 type 4 datasheet",
        "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation A50mm, soft annealed temper R500, minimum",
      "value": 25,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "Permimphy N14080 type 4",
        "temper": "R500 soft annealed",
        "gauge_length": "50 mm"
      },
      "method": "Minimum value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "matthey-permimphy",
      "where": "Mechanical properties of strips table, row R500 soft annealed, column A50mm",
      "source_detail": {
        "title": "Lamineries Matthey, Mumetal Permimphy N14080 type 4 datasheet",
        "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, final annealed",
      "value": 530,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "Mu-metal",
        "temper": "final annealed (after dry hydrogen heat treatment)",
        "form": "typical final annealed properties"
      },
      "method": "Typical value printed on a manufacturer web page",
      "status": "ground",
      "source": "msc-mumetal-web",
      "where": "Typical Final Annealed Properties block, row Tensile Strength",
      "source_detail": {
        "title": "Magnetic Shields Limited, Mu Metal specifications page (mumetal.co.uk)",
        "url": "https://mumetal.co.uk/?p=100",
        "kind": "web",
        "license": "Manufacturer web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength 0.2 %, final annealed",
      "value": 160,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "Mu-metal",
        "temper": "final annealed (after dry hydrogen heat treatment)",
        "measure": "0.2 % offset"
      },
      "method": "Typical value printed on a manufacturer web page",
      "status": "ground",
      "source": "msc-mumetal-web",
      "where": "Typical Final Annealed Properties block, row 0.2 % Yield Strength",
      "source_detail": {
        "title": "Magnetic Shields Limited, Mu Metal specifications page (mumetal.co.uk)",
        "url": "https://mumetal.co.uk/?p=100",
        "kind": "web",
        "license": "Manufacturer web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, final annealed",
      "value": 45,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "Mu-metal",
        "temper": "final annealed (after dry hydrogen heat treatment)"
      },
      "method": "Typical value printed on a manufacturer web page",
      "status": "ground",
      "source": "msc-mumetal-web",
      "where": "Typical Final Annealed Properties block, row Elongation",
      "source_detail": {
        "title": "Magnetic Shields Limited, Mu Metal specifications page (mumetal.co.uk)",
        "url": "https://mumetal.co.uk/?p=100",
        "kind": "web",
        "license": "Manufacturer web page (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength after in-process anneal, maximum",
      "value": 690,
      "bound": "upper",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "HyMu 800, 80 Ni 5 Mo",
        "temper": "after in-process strand anneal at 1000/1050 °C, before further cold rolling"
      },
      "method": "Maximum value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "carpenter-hymu800",
      "where": "Heat Treatment, In-Process Anneal paragraph (100 ksi (690 MPa) maximum)",
      "source_detail": {
        "title": "CarTech HyMu 800 alloy data sheet, Carpenter Technology",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/HyMu%20800.pdf",
        "kind": "datasheet",
        "license": "Manufacturer data sheet, typical values (cited, not reproduced)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Uncoated, in ordinary air",
      "headline": "The high nickel content lets the alloy be used without a corrosion-resistant coating.",
      "effect": "The Permimphy datasheet says the high nickel content allows use of this material without a corrosion resistant coating. No corrosion rate, humidity test or salt-spray result is printed in the sources read.",
      "rating": "low",
      "conditions": {
        "grade": "Permimphy N14080 type 4",
        "exposure": "not stated",
        "basis": "manufacturer statement, no test data"
      },
      "source": "matthey-permimphy",
      "where": "Main technical properties and features, first paragraph"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem's GHS record for nickel (CID 935) lists H317 (may cause an allergic skin reaction), H351 (suspected of causing cancer) and H372 (causes damage to organs through prolonged or repeated exposure), signal word Danger. These are the classes for nickel metal, not for the alloy, which is not separately classified in the sources read; the alloy is about 80 % nickel.",
        "ghs": [
          "H317",
          "H351",
          "H372"
        ],
        "source": "pubchem-ni",
        "where": "GHS Classification section, Hazard Statements"
      }
    ],
    "failure_risks": [
      {
        "mode": "Permeability loss from shock or plastic strain",
        "trigger": "Severe shock, forming or further mechanical working after the final anneal",
        "consequence": "The Magnetic Shield page says the enlarged grains are susceptible to severe shocks or further mechanical working, and the permeability will decrease in those areas. A re-anneal can restore it.",
        "severity": "moderate",
        "source": "msc-mumetal-web",
        "where": "Heat treatment paragraph after the dry hydrogen anneal description"
      },
      {
        "mode": "Contamination or oxidation during the anneal",
        "trigger": "Heat treatment without a protective atmosphere, or with parts not cleaned or handled with care",
        "consequence": "Permimphy says a protective atmosphere is essential to avoid oxidation, that treated parts must avoid plastic deformation which degrades the magnetic properties, and that parts must be degreased and cleaned first.",
        "severity": "moderate",
        "source": "matthey-permimphy",
        "where": "Heat treatment of finished parts paragraph"
      }
    ],
    "side_effects": [
      {
        "text": "The MuMETAL sheet gives a density of 8.7 g/cm3, so shields and cored components add mass.",
        "affects": "Mass of a shield or cored component",
        "source": "msc-mumetal",
        "where": "Physical Properties table, row Density"
      }
    ],
    "handling": [
      {
        "text": "The Carpenter sheet says oil, grease, lacquer and all other contaminants must be removed before annealing, and parts should be separated by an inert powder such as magnesium or aluminium oxide during the hydrogen anneal. It recommends an oxygen-free, dry hydrogen anneal with a dew point below -40 °C, at 2050/2150 °F (1120/1177 °C), held 2 to 4 hours.",
        "source": "carpenter-hymu800",
        "where": "Heat Treatment, Thermal Treatment for Magnetic Properties paragraph"
      },
      {
        "text": "The Permimphy sheet recommends pure dry hydrogen for the anneal, between 800 and 1150 °C, with anhydrous inert powder to keep parts apart.",
        "source": "matthey-permimphy",
        "where": "Heat treatment of finished parts paragraph"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Magnetic shielding for sensitive electronics, current sensors and current transformer cores",
      "example": "The MuMETAL sheet datasheet says MuMETAL bar is used in high quality magnetic shielding, current sensors, high precision current transformer cores and ground fault circuit breaker relay parts.",
      "source": "msc-mumetal",
      "where": "Description paragraph"
    },
    {
      "application": "electronics-and-chips",
      "device": "Relays, stepper motors and magnetic sensors",
      "example": "Permimphy's main applications include relays for ground fault circuit breakers and railway signalling, stepper motors for watches, shielding and magnetic sensors for current, angular position and displacement.",
      "source": "matthey-permimphy",
      "where": "Typical uses paragraph"
    },
    {
      "application": "electronics-and-chips",
      "device": "Spacecraft magnetic cleanliness, soft magnetic parts near magnetometers",
      "example": "NASA SP-8018, a 1969 spacecraft design criteria document, names Mu-metal, with mild steel, as an example of a soft magnetic material in its guidance on magnetic cleanliness. It warns that enclosing a component in a highly permeable container can create problems for the shielded component.",
      "source": "nasa-sp8018",
      "where": "Section on magnetic materials, paragraph on hard and soft materials; Shielding paragraph (reference 37)"
    }
  ],
  "supply": [
    {
      "subject": "Nickel (about 80 % of the alloy)",
      "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": [],
      "recycling": "USGS: in 2025 nickel recovered from scrap accounted for approximately 60 % of apparent consumption, and most secondary nickel was in the form of stainless steel scrap.",
      "substitutes": [],
      "source": "usgs-mcs2026-nickel",
      "where": "World Mine Production and Reserves table, 2025e column, metric tons of nickel content: Indonesia 2,600,000; Philippines 270,000; Russia 200,000; world total 3,900,000 (shares calculated by Space Mushroom from these figures). Recycling paragraph."
    },
    {
      "subject": "Molybdenum (about 5 % of the alloy)",
      "producers": [
        {
          "country": "China",
          "share_percent": 37.3,
          "year": 2025
        },
        {
          "country": "Chile",
          "share_percent": 16.2,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 15,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: molybdenum is recycled as a component of catalysts, ferrous scrap and superalloy scrap, and the molybdenum content of recycled alloys is significant and reused.",
      "substitutes": [
        "USGS: there is little substitution for molybdenum in its major application in steels and cast irons."
      ],
      "source": "usgs-mcs2026-molybdenum",
      "where": "World Mine Production and Reserves table, 2025e column, thousand metric tons: China 97,000; Chile 42,000; Peru 39,000; world total 260,000 (shares calculated by Space Mushroom). Events, Trends and Issues: China, Chile, the United States, Peru and Mexico produced 90 % of world output in 2025."
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data",
      "type": "datasheet",
      "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf"
    },
    {
      "title": "CarTech HyMu 800 alloy datasheet (Carpenter Technology, 2020 copyright)",
      "type": "datasheet",
      "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/HyMu%20800.pdf",
      "year": 2020
    },
    {
      "title": "Lamineries Matthey, Mumetal Permimphy datasheet",
      "type": "datasheet",
      "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf"
    },
    {
      "title": "Wikipedia: Mu-metal",
      "type": "report",
      "url": "https://en.wikipedia.org/wiki/Mu-metal"
    },
    {
      "title": "NASA SP-8018, Space Vehicle Design Criteria (Guidance and Control), NTRS 19690020961",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/19690020961",
      "year": 1969
    },
    {
      "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: Molybdenum",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf",
      "year": 2026
    },
    {
      "title": "PubChem compound record for nickel (CID 935), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Nickel"
    }
  ],
  "gaps": [
    "No flight-proven mu-metal magnetic shield on a named spacecraft was found in this run. MAVEN and MMS magnetometer papers mention mu-metal test chambers, but the full texts were not read (the Springer PDF was blocked), so the only space use entered is the NASA SP-8018 design guidance.",
    "The DAMPE satellite calorimeter (arXiv 1309.7638) shielded a photomultiplier with a permalloy cylinder, not mu-metal, so it is not entered as a mu-metal use.",
    "The MuMETAL sheet mechanical table (tensile 650 MPa, yield 280 MPa, elongation 35 %, hardness 130 to 170 HV) gives no temper, so it is not entered. The Permimphy and final-annealed values are used instead.",
    "The HyMu 800 magnetic curves (DC, 60 Hz and 400 Hz permeability and core loss) are graphs with no printed table in the PDF, so no values were taken from them.",
    "The Permimphy electrical resistivity is printed as 55 with no unit, so it is not entered. The MuMETAL sheet gives 60 µΩ·cm.",
    "The mumetal.co.uk page gives 4.5 % molybdenum, which conflicts with 5 % in the other sources, so its composition is not used. The Wikipedia range of 12 to 15 % iron is a different formulation and is not used.",
    "Corrosion rate and salt-spray or humidity data for mu-metal were not found. The only corrosion statement is a manufacturer claim that the high nickel content needs no coating.",
    "No ASTM A753 standard text was opened, so the grade limits for Alloy 4 are taken from the Carpenter and Matthey datasheets only. The Fabdigit page was blocked by a security checkpoint.",
    "The GHS hazard codes are for nickel metal (PubChem CID 935). No hazard classification of the 80Ni-5Mo alloy itself was found.",
    "Whether nickel or molybdenum is on the U.S. 2025 final critical minerals list was not confirmed in the USGS text read, so critical_lists is empty for both.",
    "Radiation effects, cold-welding and outgassing data for mu-metal were not looked up.",
    "Dates for the HyMu 800 datasheet: the PDF gives an edition date of 11/01/1991 and a 2020 copyright, so the version is uncertain."
  ],
  "story": {
    "why": "Mu-metal is used to shield sensitive electronics from static and low-frequency magnetic fields. It is a soft nickel-iron-molybdenum alloy with nominal 80 % Ni and 5 % Mo, and its high permeability gives a low-reluctance path for the field. The MuMETAL sheet datasheet gives a DC permeability of at least 400,000 at 0.005 Oe and an AC permeability of at least 75,000 at 60 Hz. The saturation induction is 0.75 T, and the Curie temperature is 420 °C. The sources read give it a yield strength of 160 MPa in the final annealed state, so it is chosen for its magnetic performance, not for its strength.",
    "uses": [
      {
        "where": "Magnetic shields and sensors",
        "line": "MuMETAL is used in high quality magnetic shielding, current sensors and high precision current transformer cores. Permimphy is used for relays, stepper motors and magnetic sensors."
      },
      {
        "where": "Spacecraft magnetic cleanliness",
        "line": "NASA SP-8018 lists Mu-metal as an example of a soft magnetic material to consider for spacecraft magnetic cleanliness, and warns that shielding by a highly permeable container can create problems."
      }
    ],
    "can_do": [
      {
        "label": "Shield a field",
        "line": "The MuMETAL sheet gives a DC permeability of at least 400,000 at 0.005 Oe, and at least 75,000 at 60 Hz and 0.4 A/m for AC.",
        "benchmark": "permeability_dc_min",
        "scope": "material",
        "value": "400000 DC permeability"
      },
      {
        "label": "Saturate at low field",
        "line": "Saturation induction is 0.75 T in the MuMETAL sheet and 0.8 T at 20 °C in the Permimphy datasheet. The alloy saturates at low fields, which keeps its hysteresis loss low in AC circuits.",
        "benchmark": "saturation_induction",
        "scope": "material",
        "value": "0.75 T"
      },
      {
        "label": "Weight",
        "line": "Density is 8.7 g/cm3 in the MuMETAL sheet, and 0.316 lb/in3 in the HyMu 800 datasheet.",
        "benchmark": "density",
        "scope": "material",
        "value": "8.7 g/cm3"
      },
      {
        "label": "Strength when annealed",
        "line": "In the final annealed state a supplier page gives 530 MPa tensile, 160 MPa yield and 45 % elongation. Soft annealed strip in the Permimphy datasheet has a tensile strength of 500 to 700 N/mm2.",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material",
        "value": "530 MPa tensile"
      }
    ],
    "compare": "The alloy is chosen to shield a field, not to carry a load, so its low yield strength matters less than its permeability. The density of 8.7 g/cm3 is the figure to weigh against any alternative shield.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "DC permeability",
        "benchmark": "permeability_dc_min",
        "scope": "material"
      },
      {
        "label": "Thermal expansion",
        "benchmark": "cte",
        "scope": "material"
      }
    ],
    "handling": [
      "Anneal in dry hydrogen with a dew point below -40 °C, after removing all oil and contaminants.",
      "Avoid shock and plastic deformation after the anneal, because the permeability falls and needs a re-anneal to recover.",
      "The only hazard codes found are for nickel metal (PubChem); treat the alloy with the same care until a supplier classification is found."
    ],
    "good_for": [
      "Shielding sensitive electronics from static and low-frequency fields: at least 400,000 DC permeability and 75,000 AC permeability at 60 Hz.",
      "Current transformer cores and relay parts, as the datasheets list.",
      "Spacecraft magnetic cleanliness design, where soft magnetic parts must be chosen with care."
    ],
    "watch_out": [
      "Soft and weak: 160 MPa yield in the final annealed state.",
      "Heavy: 8.7 g/cm3, so a shield adds mass.",
      "Permeability is lost after shock or forming, and the alloy needs a re-anneal to recover.",
      "No corrosion rate or flight record was found for the alloy; the only statement is a manufacturer's claim that no coating is needed.",
      "The only hazard codes found are for nickel metal, not for the alloy."
    ],
    "verdict": "Mu-metal is a soft nickel-iron-molybdenum alloy with very high permeability, nominally 80 % Ni and 5 % Mo, used to shield sensitive electronics. It is heavy and weak, and its permeability depends on a careful dry hydrogen anneal and on keeping the part free of shock and deformation. Spacecraft use is documented as design guidance; no flight record was found in this run.",
    "recipe": {
      "line": "Mu-metal is a nickel-iron-molybdenum alloy, nominally 80 % Ni and 5 % Mo, with balance Fe and small manganese and silicon (CarTech HyMu 800 type analysis; MuMETAL sheet typical composition 80 Ni, 5.0 Mo, Mn 0.3 to 0.5, Si 0.1 to 0.4). Its magnetic properties come from a final anneal in dry hydrogen; the HyMu 800 datasheet gives 2050/2150 °F (1120/1177 °C) for low-frequency response, and the Permimphy datasheet gives 800 to 1150 °C.",
      "parts": [
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Main element of the alloy, nominal 80 %",
          "share_percent": 80,
          "share_note": "nominal, 80.00 % in the type analysis",
          "source": "carpenter-hymu800",
          "where": "Type Analysis table, Nickel 80.00 %"
        },
        {
          "name": "Molybdenum",
          "symbol": "Mo",
          "role": "Alloying element; the Permimphy datasheet says molybdenum increases magnetic permeability",
          "share_percent": 5,
          "share_note": "nominal, 5.00 % in the type analysis",
          "source": "carpenter-hymu800",
          "where": "Type Analysis table, Molybdenum 5.00 %"
        },
        {
          "name": "Manganese",
          "symbol": "Mn",
          "role": "Minor element, nominal",
          "share_percent": 0.5,
          "share_note": "nominal, 0.50 %",
          "source": "carpenter-hymu800",
          "where": "Type Analysis table, Manganese 0.50 %"
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Minor element, nominal",
          "share_percent": 0.15,
          "share_note": "nominal, 0.15 %",
          "source": "carpenter-hymu800",
          "where": "Type Analysis table, Silicon 0.15 %"
        },
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "Balance of the alloy",
          "share_note": "balance",
          "source": "carpenter-hymu800",
          "where": "Type Analysis table, Iron Balance"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The hazard classes in the sources are for nickel metal, which makes up about 80 % of the alloy. No separate classification of the alloy was found.",
        "points": [
          {
            "label": "Nickel as a substance",
            "line": "PubChem's GHS record for nickel lists H317 allergic skin reaction, H351 suspected cancer and H372 organ damage from repeated exposure, with signal word Danger."
          },
          {
            "label": "Alloy as handled",
            "line": "No health classification of the 80Ni-5Mo alloy itself was found in the sources read."
          }
        ],
        "level": 1,
        "verdict": "Nickel classes"
      },
      {
        "title": "If it fails",
        "lead": "The failure routes in the sources are mechanical and thermal. None of them is a flight result for mu-metal.",
        "points": [
          {
            "label": "Shock and forming",
            "line": "Severe shock or further mechanical working after the anneal lowers the permeability in the affected areas. A re-anneal can restore it."
          },
          {
            "label": "Poor anneal",
            "line": "Oxidation or contamination during the hydrogen anneal, or plastic deformation of the treated part, degrades the magnetic properties."
          },
          {
            "label": "Mass",
            "line": "At 8.7 g/cm3 the alloy is heavy, so a shield adds mass to the spacecraft or instrument."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Clean before anneal",
            "line": "Remove oil, grease, lacquer and contaminants before annealing. Separate parts with inert powder such as magnesium or aluminium oxide."
          },
          {
            "label": "Anneal in dry hydrogen",
            "line": "The HyMu 800 datasheet recommends an oxygen-free, dry hydrogen anneal with a dew point below -40 °C, held 2 to 4 hours at 1120 to 1177 °C (2050/2150 °F)."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 27,
    "unreachable": 2,
    "caveats": 6,
    "note": "Values were read by an AI assistant on 2026-10-26 from the datasheets, web pages and reports named in each entry. Unreachable: the MAVEN and MMS Springer full texts (blocked) and the Fabdigit page (security checkpoint). Caveats: the 80Ni-5Mo values come from three manufacturers and a supplier web page with typical or nominal figures; the permeability and strength values are typical, not guaranteed; the spacecraft use is design guidance, not a flight record; the hazard codes are for nickel metal; the supply shares are calculated from USGS tonnages."
  },
  "sources": {
    "msc-mumetal": {
      "title": "Magnetic Shield Corporation, MuMETAL stress annealed sheet data sheet",
      "url": "https://www.magnetic-shield.com/content/MuMetal%20Stress%20Annealed%20Sheet%20Data.pdf",
      "kind": "datasheet",
      "license": "Manufacturer datasheet (cited, not reproduced)"
    },
    "msc-mumetal-web": {
      "title": "Magnetic Shields Limited, Mu Metal specifications page (mumetal.co.uk)",
      "url": "https://mumetal.co.uk/?p=100",
      "kind": "web",
      "license": "Manufacturer web page (cited, not reproduced)"
    },
    "carpenter-hymu800": {
      "title": "CarTech HyMu 800 alloy data sheet, Carpenter Technology",
      "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/HyMu%20800.pdf",
      "kind": "datasheet",
      "license": "Manufacturer data sheet, typical values (cited, not reproduced)"
    },
    "matthey-permimphy": {
      "title": "Lamineries Matthey, Mumetal Permimphy N14080 type 4 datasheet",
      "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/Permimphy_v22E.pdf",
      "kind": "datasheet",
      "license": "Manufacturer data sheet (cited, not reproduced)"
    },
    "wikipedia-mumetal": {
      "title": "Wikipedia: Mu-metal",
      "url": "https://en.wikipedia.org/wiki/Mu-metal",
      "kind": "web",
      "license": "CC BY-SA (cited, not reproduced)"
    },
    "nasa-sp8018": {
      "title": "NASA SP-8018, Space Vehicle Design Criteria (Guidance and Control), magnetic materials and shielding sections",
      "id": "NTRS 19690020961",
      "url": "https://ntrs.nasa.gov/citations/19690020961",
      "year": 1969,
      "kind": "report",
      "license": "NASA public document (cited, not reproduced)"
    },
    "usgs-mcs2026-nickel": {
      "title": "USGS Mineral Commodity Summaries 2026: Nickel",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf",
      "year": 2026,
      "kind": "report",
      "license": "Public domain (USGS)"
    },
    "usgs-mcs2026-molybdenum": {
      "title": "USGS Mineral Commodity Summaries 2026: Molybdenum",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf",
      "year": 2026,
      "kind": "report",
      "license": "Public domain (USGS)"
    },
    "pubchem-ni": {
      "title": "PubChem compound record: Nickel (CID 935), GHS classification",
      "id": "CID 935",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Nickel",
      "kind": "database",
      "license": "PubChem (NCBI), public domain; sections attributed to ECHA and notifiers"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/mu-metal/"
}