{
  "spore": "profile",
  "id": "alloy-42",
  "spore_version": "0.2",
  "family": "nickel-alloys",
  "name": "Alloy 42",
  "abbreviation": "FeNi42",
  "role": "controlled-expansion alloy for glass and ceramic seals",
  "category": "metals",
  "type": "nickel-superalloys",
  "summary": "Alloy 42 is a binary nickel-iron alloy with 42 % nickel (UNS K94100, Werkstoff Nr. 1.3917), used where a low, nearly constant thermal expansion is needed up to about 300 °C. Special Metals gives a density of 8.11 g/cm3 and a mean linear expansion of 5.3 ppm/K from 20 to 300 °C, while NeoNickel prints 4.0 to 4.7 ppm/K from 30 to 300 °C. The two suppliers disagree, so both figures are kept. Annealed bar has a tensile strength of 490 MPa and a yield strength of 250 MPa at 20 °C in the Special Metals table.\n",
  "best_for": "Glass-to-metal and ceramic-to-metal seals, and lead frames for integrated circuits, where expansion must stay low up to 300 °C",
  "weakest_at": "Strength and corrosion data: no corrosion test was found, and the sources disagree on yield strength, tensile strength and elongation",
  "identity": {
    "formula": "Fe-42Ni, nominal: a binary nickel-iron alloy with 41 % nickel minimum (42 % nominal) and iron as the balance; carbon 0.05 % maximum, manganese 0.8 % maximum, silicon 0.03 % maximum, chromium 0.25 % maximum, phosphorus and sulphur 0.025 % maximum, aluminium 0.1 % maximum (NeoNickel chemical analysis)",
    "designations": [
      {
        "system": "UNS",
        "code": "K94100",
        "source": "nilo-smc031",
        "where": "Specifications and designations, NILO alloy 42 (UNS K94100, W.Nr. 1.3917)"
      },
      {
        "system": "EN",
        "code": "1.3917",
        "source": "nilo-smc031",
        "where": "Specifications and designations, NILO alloy 42 (UNS K94100, W.Nr. 1.3917)"
      },
      {
        "system": "ASTM",
        "code": "F30",
        "note": "sheet, strip, rod, bar, tubing and wire",
        "source": "nilo-smc031",
        "where": "Specifications and designations, ASTM F 30 row"
      },
      {
        "system": "ASTM",
        "code": "F29",
        "note": "wire",
        "source": "nilo-smc031",
        "where": "Specifications and designations, ASTM F 29 (Wire) row"
      },
      {
        "system": "ASTM",
        "code": "B753",
        "note": "sheet and strip",
        "source": "nilo-smc031",
        "where": "Specifications and designations, ASTM B 753 (Sheet and strip) row"
      },
      {
        "system": "DIN",
        "code": "17745",
        "source": "nilo-smc031",
        "where": "Specifications and designations, DIN 17745 (Composition) row"
      },
      {
        "system": "AFNOR",
        "code": "NF A54-301",
        "note": "composition",
        "source": "nilo-smc031",
        "where": "Specifications and designations, AFNOR NF A54-301 (Composition) row"
      },
      {
        "system": "ASTM",
        "code": "F1684",
        "note": "specification named by NeoNickel",
        "source": "studer-alloy42",
        "where": "Page title, 1.3917 - Alloy 42/FeNi42 / Ni42 / F1684 / K94100"
      },
      {
        "system": "Trade name",
        "code": "Nilo 42",
        "source": "aircraftmaterials-al42",
        "where": "Specifications list, Tradename Nilo 42"
      }
    ],
    "source": "nilo-smc031",
    "where": "Table 1 (Nominal compositions, NILO alloy 42: Ni 42.0, Fe 58.0) and the opening description ('a binary nickel-iron alloy containing 42% nickel'); maximum limits from the NeoNickel chemical analysis table"
  },
  "tags": {
    "environments": [],
    "stresses": [
      "extreme-cold"
    ],
    "applications": [
      "electronics-and-chips",
      "cryogenic-fuel",
      "mechanisms",
      "structures"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, NILO alloy 42 (Special Metals)",
      "value": 8.11,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "temperature": "not stated in Table 2",
        "unit_in_source": "0.293 lb/in3"
      },
      "method": "Value printed in a Special Metals technical bulletin (publication SMC-031, Sept 2004)",
      "status": "ground",
      "source": "nilo-smc031",
      "where": "Table 2 (Density), row NILO alloy 42",
      "source_detail": {
        "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
        "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
        "year": 2004,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, Alloy 42 (NeoNickel)",
      "value": 8.12,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "temperature": "not stated"
      },
      "method": "Value printed in a stockist product page (NeoNickel)",
      "status": "ground",
      "note": "Differs from the 8.11 g/cm3 printed by Special Metals; both are kept.",
      "source": "neonickel-alloy42",
      "where": "Key Properties, row Density",
      "source_detail": {
        "title": "Alloy 42, NeoNickel product page (Key Properties, Chemical analysis, Characteristics)",
        "id": "NeoNickel, Alloy 42 page; UNS K94100",
        "url": "https://www.neonickel.com/alloys/all-alloys/alloy-42",
        "year": 2026,
        "kind": "web",
        "license": "stockist web page, cited not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting range, Alloy 42 (NeoNickel)",
      "value": 1425,
      "value_high": 1435,
      "bound": "range",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "basis": "melting range as printed",
        "unit_in_source": "1425°C - 1435°C"
      },
      "method": "Range printed in a stockist product page (NeoNickel)",
      "status": "ground",
      "source": "neonickel-alloy42",
      "where": "Key Properties, row Melting Range",
      "source_detail": {
        "title": "Alloy 42, NeoNickel product page (Key Properties, Chemical analysis, Characteristics)",
        "id": "NeoNickel, Alloy 42 page; UNS K94100",
        "url": "https://www.neonickel.com/alloys/all-alloys/alloy-42",
        "year": 2026,
        "kind": "web",
        "license": "stockist web page, cited not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, NILO alloy 42 (Special Metals)",
      "value": 1435,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "unit_in_source": "2615 °F"
      },
      "method": "Value printed in a Special Metals technical bulletin, Table 3",
      "status": "ground",
      "note": "Special Metals gives a single figure at the top of the NeoNickel range.",
      "source": "nilo-smc031",
      "where": "Table 3 (Melting and Inflection Points), row NILO alloy 42",
      "source_detail": {
        "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
        "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
        "year": 2004,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, Alloy 42 (High Temp Metals)",
      "value": 1427,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "unit_in_source": "2600 °F"
      },
      "method": "Value printed in a supplier technical data sheet",
      "status": "ground",
      "source": "hightemp-alloy42",
      "where": "Physical Properties table, row Melting Point, °C column",
      "source_detail": {
        "title": "Alloy 42 Technical Data (High Temp Metals)",
        "id": "High Temp Metals, Alloy 42 technical data page",
        "url": "https://hightempmetals.com/techdata/hitempInvar42data.php",
        "year": 2015,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "curie_temperature",
      "label": "Curie temperature, Alloy 42 (NeoNickel)",
      "value": 380,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "basis": "as printed on the product page; no test method given"
      },
      "method": "Value printed in a stockist product page (NeoNickel)",
      "status": "ground",
      "note": "High Temp Metals prints the same 380 °C (715 °F).",
      "source": "neonickel-alloy42",
      "where": "Key Properties, row Curie Temperature",
      "source_detail": {
        "title": "Alloy 42, NeoNickel product page (Key Properties, Chemical analysis, Characteristics)",
        "id": "NeoNickel, Alloy 42 page; UNS K94100",
        "url": "https://www.neonickel.com/alloys/all-alloys/alloy-42",
        "year": 2026,
        "kind": "web",
        "license": "stockist web page, cited not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, NILO alloy 42 (Special Metals)",
      "value": 10.5,
      "bound": "exact",
      "unit": "W/m°C",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C (68 °F)",
        "unit_in_source": "W/m°C; 72.8 Btu in/ft2h °F"
      },
      "method": "Value printed in a Special Metals technical bulletin, Table 4",
      "status": "ground",
      "source": "nilo-smc031",
      "where": "Table 4 (Thermal Conductivity at 20 °C), row NILO alloy 42",
      "source_detail": {
        "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
        "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
        "year": 2004,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, Alloy 42 (NeoNickel)",
      "value": 10.7,
      "bound": "exact",
      "unit": "W/m-K",
      "scope": "material",
      "conditions": {
        "temperature": "20/100 °C, as printed"
      },
      "method": "Value printed in a stockist product page (NeoNickel)",
      "status": "ground",
      "note": "Special Metals gives 10.5 W/m°C at 20 °C; High Temp Metals prints 10.7 W/m-K at 20/100 °C too.",
      "source": "neonickel-alloy42",
      "where": "Key Properties, row Thermal Conductivity at 20/100°C",
      "source_detail": {
        "title": "Alloy 42, NeoNickel product page (Key Properties, Chemical analysis, Characteristics)",
        "id": "NeoNickel, Alloy 42 page; UNS K94100",
        "url": "https://www.neonickel.com/alloys/all-alloys/alloy-42",
        "year": 2026,
        "kind": "web",
        "license": "stockist web page, cited not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean linear expansion, 20 to 300 °C, typical (Special Metals)",
      "value": 5.3,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "temperature_range": "20 to 300 °C (68 to 572 °F)",
        "basis": "typical mean linear coefficient for NILO alloy 42 as printed",
        "unit_in_source": "10-6/°C"
      },
      "method": "Typical value printed in a Special Metals technical bulletin, Table 8 (not a guaranteed minimum or maximum)",
      "status": "ground",
      "note": "Differs from the 4.0 to 4.7 ppm/K printed by NeoNickel and High Temp Metals for 30 to 300 °C; both are kept and the sources are not reconciled.",
      "source": "nilo-smc031",
      "where": "Table 8 (Typical Thermal Expansion of NILO alloy 42), row 20-300",
      "source_detail": {
        "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
        "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
        "year": 2004,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean linear expansion, 30 to 300 °C (NeoNickel)",
      "value": 4,
      "value_high": 4.7,
      "bound": "range",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "temperature_range": "30 to 300 °C",
        "unit_in_source": "10-6/°C"
      },
      "method": "Range printed on a stockist product page (NeoNickel); High Temp Metals prints the same range",
      "status": "ground",
      "source": "neonickel-alloy42",
      "where": "Key Properties, Coefficient of Thermal Expansion, row 30 to 300°C",
      "source_detail": {
        "title": "Alloy 42, NeoNickel product page (Key Properties, Chemical analysis, Characteristics)",
        "id": "NeoNickel, Alloy 42 page; UNS K94100",
        "url": "https://www.neonickel.com/alloys/all-alloys/alloy-42",
        "year": 2026,
        "kind": "web",
        "license": "stockist web page, cited not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean linear expansion, 30 to 450 °C (NeoNickel)",
      "value": 6.7,
      "value_high": 7.4,
      "bound": "range",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "temperature_range": "30 to 450 °C",
        "unit_in_source": "10-6/°C"
      },
      "method": "Range printed on a stockist product page (NeoNickel)",
      "status": "ground",
      "source": "neonickel-alloy42",
      "where": "Key Properties, Coefficient of Thermal Expansion, row 30 to 450°C",
      "source_detail": {
        "title": "Alloy 42, NeoNickel product page (Key Properties, Chemical analysis, Characteristics)",
        "id": "NeoNickel, Alloy 42 page; UNS K94100",
        "url": "https://www.neonickel.com/alloys/all-alloys/alloy-42",
        "year": 2026,
        "kind": "web",
        "license": "stockist web page, cited not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Elastic modulus, NILO alloy 42 (Special Metals)",
      "value": 150,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "not stated in Table 16",
        "unit_in_source": "21.8 x 10^3 ksi"
      },
      "method": "Value printed in a Special Metals technical bulletin, Table 16",
      "status": "ground",
      "source": "nilo-smc031",
      "where": "Table 16 (Elastic Modulus Data), row NILO alloy 42",
      "source_detail": {
        "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
        "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
        "year": 2004,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Elastic modulus at 20 °C, Alloy 42 (NeoNickel)",
      "value": 148,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C"
      },
      "method": "Value printed in a stockist product page (NeoNickel)",
      "status": "ground",
      "source": "neonickel-alloy42",
      "where": "Key Properties, row Modulus of Elasticity at 20°C",
      "source_detail": {
        "title": "Alloy 42, NeoNickel product page (Key Properties, Chemical analysis, Characteristics)",
        "id": "NeoNickel, Alloy 42 page; UNS K94100",
        "url": "https://www.neonickel.com/alloys/all-alloys/alloy-42",
        "year": 2026,
        "kind": "web",
        "license": "stockist web page, cited not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength (0.2% offset), annealed bar at 20 °C (Special Metals)",
      "value": 250,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temper": "annealed, hot-rolled bar",
        "temperature": "20 °C (68 °F)",
        "test": "0.2% offset",
        "unit_in_source": "36.0 ksi"
      },
      "method": "Value printed in a Special Metals technical bulletin, Table 12",
      "status": "ground",
      "source": "nilo-smc031",
      "where": "Table 12 (Typical Mechanical Properties of NILO alloy 42), 20 °C row",
      "source_detail": {
        "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
        "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
        "year": 2004,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength (0.2% offset), annealed at room temperature (Aircraft Materials)",
      "value": 250,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temper": "annealed",
        "test": "0.2% offset",
        "unit_in_source": "36,000 psi"
      },
      "method": "Value printed in a supplier technical data sheet (Typical Mechanical Properties table)",
      "status": "ground",
      "source": "aircraftmaterials-al42",
      "where": "Typical Mechanical Properties table, row Alloy 42 (Nilo 42), annealed",
      "source_detail": {
        "title": "Nickel Iron Alloy 42 / Nilo 42 (ASTM F30), Technical Data Sheet (Aircraft Materials)",
        "id": "Aircraft Materials, UNS K94100",
        "url": "https://aircraftmaterials.com/data/nickel/al42.html",
        "year": 2013,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, annealed bar at 20 °C (Special Metals)",
      "value": 490,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temper": "annealed, hot-rolled bar",
        "temperature": "20 °C (68 °F)",
        "unit_in_source": "71.0 ksi"
      },
      "method": "Value printed in a Special Metals technical bulletin, Table 12",
      "status": "ground",
      "note": "The same 490 MPa is printed by Aircraft Materials for annealed material; High Temp Metals prints 517 MPa.",
      "source": "nilo-smc031",
      "where": "Table 12 (Typical Mechanical Properties of NILO alloy 42), 20 °C row",
      "source_detail": {
        "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
        "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
        "year": 2004,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, annealed material (High Temp Metals)",
      "value": 517,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temper": "annealed, material as tested by the supplier",
        "unit_in_source": "75 ksi"
      },
      "method": "Typical value printed in a supplier technical data sheet",
      "status": "ground",
      "note": "Differs from the 490 MPa printed by Special Metals and Aircraft Materials; both are kept.",
      "source": "hightemp-alloy42",
      "where": "Typical Mechanical Properties table, annealed row",
      "source_detail": {
        "title": "Alloy 42 Technical Data (High Temp Metals)",
        "id": "High Temp Metals, Alloy 42 technical data page",
        "url": "https://hightempmetals.com/techdata/hitempInvar42data.php",
        "year": 2015,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation on 50 mm (2 in), annealed bar at 20 °C (Special Metals)",
      "value": 43,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temper": "annealed, hot-rolled bar",
        "temperature": "20 °C (68 °F)",
        "gauge": "50 mm (2 inch)"
      },
      "method": "Value printed in a Special Metals technical bulletin, Table 12",
      "status": "ground",
      "source": "nilo-smc031",
      "where": "Table 12 (Typical Mechanical Properties of NILO alloy 42), 20 °C row, elongation column",
      "source_detail": {
        "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
        "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
        "year": 2004,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation in 2 in, annealed (High Temp Metals)",
      "value": 30,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temper": "annealed",
        "gauge": "2 in"
      },
      "method": "Typical value printed in a supplier technical data sheet",
      "status": "ground",
      "note": "Differs from the 43 % printed by Special Metals; both are kept.",
      "source": "hightemp-alloy42",
      "where": "Typical Mechanical Properties table, annealed row, % Elongation in 2 in column",
      "source_detail": {
        "title": "Alloy 42 Technical Data (High Temp Metals)",
        "id": "High Temp Metals, Alloy 42 technical data page",
        "url": "https://hightempmetals.com/techdata/hitempInvar42data.php",
        "year": 2015,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity at 20 °C, NILO alloy 42 (Special Metals)",
      "value": 61,
      "bound": "exact",
      "unit": "microhm-cm",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C (68 °F)",
        "unit_in_source": "61 microhm cm (367 ohm circ mil/ft)"
      },
      "method": "Value printed in a Special Metals technical bulletin, Table 6",
      "status": "ground",
      "source": "nilo-smc031",
      "where": "Table 6 (Electrical Resistivity), row 20 °C, NILO alloy 42 column",
      "source_detail": {
        "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
        "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
        "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
        "year": 2004,
        "kind": "datasheet",
        "license": "manufacturer document, linked not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, Alloy 42 (High Temp Metals)",
      "value": 66,
      "bound": "exact",
      "unit": "microhm-cm",
      "scope": "material",
      "conditions": {
        "temperature": "not stated",
        "unit_in_source": "400 ohm-cir mil/ft"
      },
      "method": "Value printed in a supplier technical data sheet",
      "status": "ground",
      "note": "Differs from the 61 microhm-cm at 20 °C printed by Special Metals; both are kept.",
      "source": "hightemp-alloy42",
      "where": "Physical Properties table, row Electrical resistivity",
      "source_detail": {
        "title": "Alloy 42 Technical Data (High Temp Metals)",
        "id": "High Temp Metals, Alloy 42 technical data page",
        "url": "https://hightempmetals.com/techdata/hitempInvar42data.php",
        "year": 2015,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat, Alloy 42 (High Temp Metals)",
      "value": 0.5,
      "bound": "exact",
      "unit": "kJ/kg-K",
      "scope": "material",
      "conditions": {
        "temperature": "not stated",
        "unit_in_source": "0.12 Btu/lb-°F"
      },
      "method": "Value printed in a supplier technical data sheet",
      "status": "ground",
      "source": "hightemp-alloy42",
      "where": "Physical Properties table, row Specific heat",
      "source_detail": {
        "title": "Alloy 42 Technical Data (High Temp Metals)",
        "id": "High Temp Metals, Alloy 42 technical data page",
        "url": "https://hightempmetals.com/techdata/hitempInvar42data.php",
        "year": 2015,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, 1.3917 Alloy 42 (METALCOR)",
      "value": 8.15,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C"
      },
      "method": "Value printed in a METALCOR datasheet, Physical Properties 20°C table",
      "status": "ground",
      "note": "Third density figure for this alloy; Special Metals gives 8.11 g/cm3 and NeoNickel 8.12 g/cm3. All three are kept.",
      "source": "metalcor-alloy42",
      "where": "Physical Properties 20°C table, row Density",
      "source_detail": {
        "title": "Alloy 42 (1.3917), K94100 datasheet (METALCOR)",
        "id": "METALCOR datasheet 80, Alloy 42",
        "url": "http://www.metalcor.de/en/datenblatt/80/",
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, 1.3917 Alloy 42 (METALCOR)",
      "value": 12.5,
      "bound": "exact",
      "unit": "W/m K",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C"
      },
      "method": "Value printed in a METALCOR datasheet, Physical Properties 20°C table",
      "status": "ground",
      "note": "Higher than the 10.5 W/m°C (Special Metals) and 10.7 W/m-K (NeoNickel) figures. All three are kept and not reconciled.",
      "source": "metalcor-alloy42",
      "where": "Physical Properties 20°C table, row Thermal conductivity",
      "source_detail": {
        "title": "Alloy 42 (1.3917), K94100 datasheet (METALCOR)",
        "id": "METALCOR datasheet 80, Alloy 42",
        "url": "http://www.metalcor.de/en/datenblatt/80/",
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength Rp (0.2% proof), lower limit at 20 °C (METALCOR)",
      "value": 300,
      "bound": "lower",
      "unit": "N/mm2",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "test": "0.2% proof (Rp) as printed",
        "basis": "lower limit printed with the sign ≥"
      },
      "method": "Lower limit printed in a METALCOR datasheet, Mechanical Properties 20°C table",
      "status": "ground",
      "note": "A lower limit, not a typical value, so it is not directly comparable with the 250 MPa typical yield from Special Metals. Both are kept.",
      "source": "metalcor-alloy42",
      "where": "Mechanical Properties 20°C table, row 0.2% yield strength Rp",
      "source_detail": {
        "title": "Alloy 42 (1.3917), K94100 datasheet (METALCOR)",
        "id": "METALCOR datasheet 80, Alloy 42",
        "url": "http://www.metalcor.de/en/datenblatt/80/",
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength Rm, lower limit at 20 °C (METALCOR)",
      "value": 500,
      "bound": "lower",
      "unit": "N/mm2",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "basis": "lower limit printed with the sign ≥"
      },
      "method": "Lower limit printed in a METALCOR datasheet, Mechanical Properties 20°C table",
      "status": "ground",
      "note": "A lower limit, not a typical value. Special Metals prints 490 MPa typical and High Temp Metals 517 MPa; all are kept.",
      "source": "metalcor-alloy42",
      "where": "Mechanical Properties 20°C table, row Tensile strength Rm",
      "source_detail": {
        "title": "Alloy 42 (1.3917), K94100 datasheet (METALCOR)",
        "id": "METALCOR datasheet 80, Alloy 42",
        "url": "http://www.metalcor.de/en/datenblatt/80/",
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, 1.3917 Alloy 42 (METALCOR)",
      "value": 145,
      "bound": "exact",
      "unit": "kN/mm2",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C"
      },
      "method": "Value printed in a METALCOR datasheet, Mechanical Properties 20°C table",
      "status": "ground",
      "note": "Lower than the 148 GPa (NeoNickel) and 150 GPa (Special Metals) figures. All three are kept.",
      "source": "metalcor-alloy42",
      "where": "Mechanical Properties 20°C table, row Modulus of elasticity",
      "source_detail": {
        "title": "Alloy 42 (1.3917), K94100 datasheet (METALCOR)",
        "id": "METALCOR datasheet 80, Alloy 42",
        "url": "http://www.metalcor.de/en/datenblatt/80/",
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Air under standard service conditions",
      "headline": "The supplier describes Alloy 42 as strongly resistant to oxidation and corrosion, with no test data given.",
      "effect": "Studer describes the alloy as having strong resistance to oxidation and corrosion under standard service conditions. The page names no environment, exposure time, test standard or corrosion rate.",
      "rating": "low",
      "conditions": {
        "basis": "qualitative supplier statement; standard service conditions not defined",
        "test": "none stated"
      },
      "source": "studer-alloy42",
      "where": "Description text, 1.3917 Alloy 42 page"
    },
    {
      "environment": "Annealing atmosphere at 850 to 1000 °C",
      "headline": "Alloy 42 is annealed at 850 to 1000 °C in a protective atmosphere, and the bulletin gives no oxidation rate.",
      "effect": "Special Metals says that NILO alloys 42 and 48 can be annealed at 850 to 1000 °C in a protective atmosphere. The bulletin does not give an oxide thickness, a scaling rate or the type of protective gas.",
      "rating": "unknown",
      "conditions": {
        "temperature_range": "850 to 1000 °C (1560 to 1830 °F)",
        "atmosphere": "protective atmosphere, type not named"
      },
      "source": "nilo-smc031",
      "where": "Heat Treatment, section NILO alloys 42 and 48"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem's GHS summary for nickel (CID 935) lists H317, 'May cause an allergic skin reaction', H351, 'Suspected of causing cancer', and H412, 'Harmful to aquatic life with long lasting effects'. Alloy 42 is 41 % nickel minimum, so these are the hazard data we hold for it.",
        "ghs": [
          "H317",
          "H351",
          "H412"
        ],
        "source": "pubchem-nickel",
        "where": "Safety and Hazards, GHS Classification summary lines (CID 935, Nickel)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Dimensional drift from cold work",
        "trigger": "Use in a cold-worked or unannealed condition where maximum dimensional stability is needed",
        "consequence": "Special Metals says the annealed condition should be used where maximum dimensional stability is required. The bulletin gives no drift figure.",
        "severity": "moderate",
        "source": "nilo-smc031",
        "where": "Heat Treatment, section NILO alloys 42 and 48"
      },
      {
        "mode": "Sulphur pick-up during hot working",
        "trigger": "Prolonged soaking in the furnace atmosphere before or during forging",
        "consequence": "High Temp Metals advises avoiding prolonged soaking to prevent sulphur absorption from the furnace atmosphere. The page gives no sulphur content or embrittlement data.",
        "severity": "low",
        "source": "hightemp-alloy42",
        "where": "Workability, Forging"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Machine in the annealed condition with high speed steel or tungsten carbide tipped tools, using straight cutting oil or soluble oil (Special Metals).",
        "source": "nilo-smc031",
        "where": "Machining section"
      },
      {
        "text": "For welding alloy 42 tooling for aerospace composites, Special Metals introduced NILO Filler Metals CF42. MIG spray and submerged arc welding are not recommended for the NILO series (Special Metals).",
        "source": "nilo-smc031",
        "where": "Fabrication section"
      },
      {
        "text": "High Temp Metals gives a forging temperature of 2150/2200 °F (1177/1204 °C) and advises avoiding prolonged soaking to prevent sulphur absorption from the furnace atmosphere.",
        "source": "hightemp-alloy42",
        "where": "Workability, Forging"
      }
    ],
    "mitigations": [
      {
        "text": "Anneal at 850 to 1000 °C in a protective atmosphere, the range Special Metals gives for NILO alloys 42 and 48, and use the annealed condition where dimensions must stay fixed.",
        "source": "nilo-smc031",
        "where": "Heat Treatment, section NILO alloys 42 and 48"
      }
    ]
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Semiconductor lead frames in integrated circuits",
      "example": "Aircraft Materials says Alloy 42 (Nilo 42) is used for semiconductor lead frames in integrated circuits.",
      "source": "aircraftmaterials-al42",
      "where": "Introduction paragraph"
    },
    {
      "application": "electronics-and-chips",
      "device": "Glass-to-metal seals in electronic tubes and lamps",
      "example": "High Temp Metals says Alloy 42 has been used for the glass-to-metal seals in electronic tubes, automotive and industrial lamps, transformer and capacitor bushings.",
      "source": "hightemp-alloy42",
      "where": "Applications"
    },
    {
      "application": "structures",
      "device": "Tooling for aerospace composites",
      "example": "Special Metals says NILO alloy 42 is used for tooling for aerospace composites and for thermostat rods.",
      "source": "nilo-smc031",
      "where": "Introduction (page 1, description of NILO alloy 42)"
    },
    {
      "application": "cryogenic-fuel",
      "device": "Cryogenic components and liquid-gas storage tanks",
      "example": "NeoNickel lists cryogenic components among the applications of Alloy 42, and says it shows low thermal expansion from cryogenic temperatures up to 300 °C.",
      "source": "neonickel-alloy42",
      "where": "Characteristics and Applications of Alloy 42"
    },
    {
      "application": "mechanisms",
      "device": "Thermostatic bimetal strip",
      "example": "Special Metals says NILO alloy 42 is used in thermostatic bi-metal strip, as the low-expansion component.",
      "source": "nilo-smc031",
      "where": "Introduction (page 1, description of NILO alloy 42)"
    },
    {
      "application": "cryogenic-fuel",
      "device": "Tanks for liquid natural gas",
      "example": "METALCOR lists tanks for liquid natural gas, with measuring and thermostatic instruments, among the applications of 1.3917 Alloy 42.",
      "source": "metalcor-alloy42",
      "where": "Application row"
    }
  ],
  "supply": [
    {
      "subject": "Nickel",
      "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
        },
        {
          "country": "Canada",
          "share_percent": 3.6,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: nickel recovered from scrap accounted for approximately 60% of apparent consumption in 2025.",
      "substitutes": [
        "USGS: titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments."
      ],
      "source": "usgs-mcs2026-nickel",
      "where": "World Mine Production and Reserves table, mine production 2025e (world total 3,900,000 t, nickel content; shares calculated by Space Mushroom from the printed country values 2,600,000, 270,000, 200,000 and 140,000 t, method approximate); Recycling; Substitutes. Critical-list status not read in this run."
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Special Metals: The NILO and NILOMAG Nickel-Iron Alloys (publication SMC-031, Sept 2004)",
      "type": "datasheet",
      "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
      "year": 2004
    },
    {
      "title": "NeoNickel: Alloy 42 product page (UNS K94100)",
      "type": "datasheet",
      "url": "https://www.neonickel.com/alloys/all-alloys/alloy-42",
      "year": 2026
    },
    {
      "title": "Aircraft Materials: Nickel Iron Alloy 42 / Nilo 42 (ASTM F30) technical data sheet",
      "type": "datasheet",
      "url": "https://aircraftmaterials.com/data/nickel/al42.html",
      "year": 2013
    },
    {
      "title": "High Temp Metals: Alloy 42 technical data",
      "type": "datasheet",
      "url": "https://hightempmetals.com/techdata/hitempInvar42data.php",
      "year": 2015
    },
    {
      "title": "Studer: 1.3917 Alloy 42/FeNi42 / Ni42 / F1684 / K94100 (product page)",
      "type": "datasheet",
      "url": "https://www.studersa.com/en/materials/13917-alloy-42-feni42-ni42-f1684-k94100;138",
      "year": 2026
    },
    {
      "title": "PubChem: Nickel (CID 935), GHS classification summary",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/935",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026, Nickel",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf",
      "year": 2026
    },
    {
      "title": "METALCOR: Alloy 42 (1.3917), K94100 datasheet",
      "type": "datasheet",
      "url": "http://www.metalcor.de/en/datenblatt/80/"
    }
  ],
  "gaps": [
    "No flight, vacuum, radiation or thermal-vacuum result for Alloy 42 was found. The two NASA reports searched (NTRS 19740012950 and 19680006647) name Kovar but not Alloy 42.",
    "No corrosion test (salt spray, humid air, immersion, or oxidation rate) was found. The only corrosion statement is a qualitative supplier phrase, and no published paper on Alloy 42 oxidation was found.",
    "No safety data sheet for Alloy 42 itself was read. The hazard data are PubChem's record for elemental nickel.",
    "Density, melting point, thermal conductivity, elongation and resistivity differ between sources; every figure is kept with its source. The METALCOR datasheet adds a third density (8.15 g/cm3) and conductivity (12.5 W/m K), and its strength values are lower limits. Special Metals and NeoNickel disagree on the expansion figures at 20 to 300 °C (5.3 against 4.0 to 4.7 ppm/K).",
    "DIN 17744 is printed by NeoNickel but DIN 17745 by Special Metals and Aircraft Materials. Only DIN 17745 is listed.",
    "Hardness (Special Metals Table 15, annealed 76 Rockwell B maximum) is not recorded because its benchmark name is not in the canonical list.",
    "Nickel's status on the USGS 2025 critical minerals list and the EU critical raw materials list was not read in this run, so critical_lists is empty.",
    "Iron supply was not read. Only nickel supply is given.",
    "Welding filler and weld-metal property data beyond the CF42 filler name were not found."
  ],
  "story": {
    "why": "Alloy 42 is a nickel-iron alloy with about 42 % nickel. Its thermal expansion is low and nearly constant from room temperature to about 300 °C, which is why it is used where it must seal to glass or ceramic, or hold a dimension while the temperature changes. The sources name lead frames in integrated circuits, glass-to-metal seals in electronic tubes and lamps, and tooling that shapes aerospace composites as its uses.",
    "uses": [
      {
        "where": "Electronic packages",
        "line": "Aircraft Materials says Alloy 42 is used for semiconductor lead frames in integrated circuits. High Temp Metals says it has been used for glass-to-metal seals in electronic tubes and lamps."
      },
      {
        "where": "Composite tooling",
        "line": "Special Metals says NILO alloy 42 is used for tooling for aerospace composites, and NeoNickel lists composite tooling among its applications."
      },
      {
        "where": "Cryogenic and bimetal parts",
        "line": "NeoNickel lists cryogenic components and liquid-gas storage tanks. Special Metals lists its use in thermostatic bi-metal strip as the low-expansion component."
      }
    ],
    "can_do": [
      {
        "label": "Low expansion",
        "line": "Holds a low, nearly constant expansion from cryogenic temperatures up to about 300 °C (NeoNickel), and NeoNickel prints a mean of 4.0 to 4.7 ppm/K from 30 to 300 °C.",
        "benchmark": "cte",
        "scope": "material",
        "value": "4.0 to 4.7 ppm/K"
      },
      {
        "label": "Strength when annealed",
        "line": "Annealed bar has a tensile strength of 490 MPa and a yield strength of 250 MPa at 20 °C (Special Metals Table 12).",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material",
        "value": "490 MPa tensile, 250 MPa yield"
      },
      {
        "label": "Stiffness",
        "line": "Elastic modulus of 150 GPa (Special Metals Table 16), against 148 GPa at 20 °C on the NeoNickel page.",
        "benchmark": "elastic_modulus",
        "scope": "material",
        "value": "150 GPa"
      }
    ],
    "compare": "Alloy 42 has a density of 8.11 g/cm3 in Special Metals' table and 8.12 g/cm3 in NeoNickel's, so the two sources differ only slightly. On expansion, Special Metals' typical table gives a mean linear coefficient of 5.3 ppm/K from 20 to 300 °C, while NeoNickel gives 4.0 to 4.7 ppm/K from 30 to 300 °C. The sources disagree on this figure, so the conditions of each value matter more than the single number. The table compares the three properties most often used to choose the alloy.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Thermal expansion",
        "benchmark": "cte",
        "scope": "material"
      },
      {
        "label": "Thermal conductivity",
        "benchmark": "thermal_conductivity",
        "scope": "material"
      }
    ],
    "handling": [
      "Machine in the annealed condition, with high speed steel or tungsten carbide tipped tools.",
      "Use NILO Filler Metals CF42 for tooling welds, and avoid MIG spray and submerged arc welding.",
      "Anneal at 850 to 1000 °C in a protective atmosphere.",
      "Avoid prolonged soaking in the furnace to prevent sulphur pick-up."
    ],
    "good_for": [
      "Low expansion to about 300 °C: 4.0 to 4.7 ppm/K from 30 to 300 °C (NeoNickel), for glass and ceramic seals.",
      "Lead frames and bimetal parts, where the alloy is named in both the Aircraft Materials and Special Metals sources."
    ],
    "watch_out": [
      "The sources disagree on expansion (5.3 against 4.0 to 4.7 ppm/K), on tensile strength (490 against 517 MPa) and on elongation (43 against 30 %).",
      "No corrosion test data were found, and the only corrosion statement is a qualitative supplier phrase.",
      "Alloy 42 is a nickel alloy, so its hazard data come from the nickel record."
    ],
    "verdict": "Alloy 42 is a low-expansion nickel-iron alloy for glass seals, lead frames and composite tooling, with consistent density and modulus data. The expansion figures and strength values differ by source, and no flight or corrosion test data were found.",
    "recipe": {
      "line": "Alloy 42 is a binary nickel-iron alloy. It is about 42 % nickel with iron as the balance, plus small maximum limits on carbon, manganese, silicon, chromium, phosphorus, sulphur and aluminium (Special Metals; NeoNickel).",
      "parts": [
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "41 % minimum in the chemical limits; the nominal 42 % gives the alloy its name (NeoNickel; Special Metals Table 1).",
          "share_percent": 41
        },
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "The balance of the composition in every limit table read."
        },
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Maximum 0.05 % (Aircraft Materials; High Temp Metals).",
          "share_high": 0.05
        },
        {
          "name": "Manganese",
          "symbol": "Mn",
          "role": "Maximum 0.8 % (NeoNickel).",
          "share_high": 0.8
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Maximum 0.03 % (NeoNickel).",
          "share_high": 0.03
        },
        {
          "name": "Chromium",
          "symbol": "Cr",
          "role": "Maximum 0.25 % (NeoNickel).",
          "share_high": 0.25
        },
        {
          "name": "Phosphorus",
          "symbol": "P",
          "role": "Maximum 0.025 % (NeoNickel).",
          "share_high": 0.025
        },
        {
          "name": "Sulphur",
          "symbol": "S",
          "role": "Maximum 0.025 % (NeoNickel).",
          "share_high": 0.025
        },
        {
          "name": "Aluminium",
          "symbol": "Al",
          "role": "Maximum 0.1 % (NeoNickel).",
          "share_high": 0.1
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "No safety data sheet for Alloy 42 itself was read. The hazard data we hold are PubChem's record for nickel, and Alloy 42 is 41 % nickel minimum.",
        "points": [
          {
            "label": "The nickel record",
            "line": "PubChem's nickel summary lists skin sensitisation, suspected cancer and harm to aquatic life. These are hazards of the element, not a test of the alloy."
          },
          {
            "label": "Dust and fume",
            "line": "Machining, grinding and welding make metal dust and fume. Handle the material as a nickel-containing alloy and avoid breathing the dust."
          }
        ],
        "level": 0,
        "verdict": "Nickel content: skin sensitiser, suspected carcinogen"
      },
      {
        "title": "If the alloy is heated",
        "lead": "These instructions come from the suppliers' heat-treatment and forging advice, not from incident reports.",
        "points": [
          {
            "label": "Annealing",
            "line": "Special Metals gives an annealing range of 850 to 1000 °C in a protective atmosphere for NILO alloys 42 and 48."
          },
          {
            "label": "Forging",
            "line": "High Temp Metals advises a forging temperature of 2150/2200 °F and avoiding prolonged soaking, which can pick up sulphur from the furnace atmosphere."
          }
        ],
        "verdict": "Hot working needs a controlled furnace atmosphere"
      },
      {
        "title": "Handling and fabrication",
        "lead": "The fabrication advice below comes from the Special Metals bulletin and the High Temp Metals data sheet.",
        "points": [
          {
            "label": "Machining",
            "line": "Machine in the annealed condition with high speed steel or tungsten carbide tipped tools."
          },
          {
            "label": "Welding",
            "line": "For tooling welds, Special Metals introduced NILO Filler Metals CF42. MIG spray and submerged arc welding are not recommended for the NILO series."
          }
        ],
        "verdict": "Machine annealed; weld with the matching filler"
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 27,
    "unreachable": 0,
    "caveats": 3,
    "note": "Read by an AI assistant on 2026-11-01. Values were read from fetched pages (Special Metals PDF, NeoNickel, Aircraft Materials, High Temp Metals, Studer). Where sources disagree, both values are kept and noted."
  },
  "sources": {
    "nilo-smc031": {
      "title": "The NILO and NILOMAG Nickel-Iron Alloys (Special Metals Corporation, publication SMC-031)",
      "id": "Special Metals SMC-031, copyright 2004 (Sept 04)",
      "url": "https://www.specialmetals.com/documents/technical-bulletins/nilo-alloys.pdf",
      "year": 2004,
      "kind": "datasheet",
      "license": "manufacturer document, linked not reproduced"
    },
    "neonickel-alloy42": {
      "title": "Alloy 42, NeoNickel product page (Key Properties, Chemical analysis, Characteristics)",
      "id": "NeoNickel, Alloy 42 page; UNS K94100",
      "url": "https://www.neonickel.com/alloys/all-alloys/alloy-42",
      "year": 2026,
      "kind": "web",
      "license": "stockist web page, cited not reproduced"
    },
    "aircraftmaterials-al42": {
      "title": "Nickel Iron Alloy 42 / Nilo 42 (ASTM F30), Technical Data Sheet (Aircraft Materials)",
      "id": "Aircraft Materials, UNS K94100",
      "url": "https://aircraftmaterials.com/data/nickel/al42.html",
      "year": 2013,
      "kind": "datasheet",
      "license": "supplier document, cited not reproduced"
    },
    "hightemp-alloy42": {
      "title": "Alloy 42 Technical Data (High Temp Metals)",
      "id": "High Temp Metals, Alloy 42 technical data page",
      "url": "https://hightempmetals.com/techdata/hitempInvar42data.php",
      "year": 2015,
      "kind": "datasheet",
      "license": "supplier document, cited not reproduced"
    },
    "studer-alloy42": {
      "title": "1.3917 - Alloy 42/FeNi42 / Ni42 / F1684 / K94100 (Studer SA, product page)",
      "id": "Studer, Werkstoffe 1.3917",
      "url": "https://www.studersa.com/en/materials/13917-alloy-42-feni42-ni42-f1684-k94100;138",
      "year": 2026,
      "kind": "web",
      "license": "stockist web page, cited not reproduced"
    },
    "pubchem-nickel": {
      "title": "PubChem compound record, Nickel (CID 935), GHS classification",
      "id": "CID 935",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/935",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "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)"
    },
    "metalcor-alloy42": {
      "title": "Alloy 42 (1.3917), K94100 datasheet (METALCOR)",
      "id": "METALCOR datasheet 80, Alloy 42",
      "url": "http://www.metalcor.de/en/datenblatt/80/",
      "kind": "datasheet",
      "license": "supplier document, cited not reproduced"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/alloy-42/"
}