{
  "spore": "profile",
  "id": "super-invar-32-5",
  "spore_version": "0.2",
  "family": "nickel-alloys",
  "name": "Super Invar 32-5",
  "abbreviation": "Super Invar",
  "role": "low-expansion structural alloy",
  "category": "metals",
  "type": "nickel-superalloys",
  "summary": "Super Invar 32-5 is an iron-nickel-cobalt alloy with a nominal 32.00 % nickel and 5.50 % cobalt, balance iron, that Carpenter Technology designs to give minimum thermal expansion at room temperatures. Hi-Temp Metals prints a mean coefficient of thermal expansion of 0.63 ppm/°C from -55 to 95 °C and a density of 8150 kg/m3. The typical yield strength is 276 MPa in the annealed condition. The 1972 JPL telescope study did not use it, because its expansion properties were unstable over long periods.\n",
  "best_for": "Parts that must hold a length near room temperature, where Carpenter says its thermal expansion is less than that of Invar 36 over -67 to 203 °F (-55 to 95 °C)",
  "weakest_at": "Long-term expansion stability (the reason the 1972 JPL study gave for not using it), and oxidation during heat treatment above about 1000 °F (538 °C)",
  "identity": {
    "formula": "Fe-32Ni-5.5Co (Super Invar 32-5): iron balance, nickel 32.00 %, cobalt 5.50 %, manganese 0.40 %, silicon 0.25 %, carbon 0.02 % (Carpenter nominal type analysis); UNS K93500",
    "designations": [
      {
        "system": "UNS",
        "code": "K93500",
        "source": "carpenter-super-invar",
        "where": "Page 1, Associated specifications line"
      },
      {
        "system": "ASTM",
        "code": "F1684",
        "note": "applicable designation for this alloy",
        "source": "carpenter-super-invar",
        "where": "Page 1, Applicable designation line"
      },
      {
        "system": "Trade name",
        "code": "Super Invar 32-5",
        "source": "carpenter-super-invar",
        "where": "Page 1 title"
      }
    ],
    "source": "carpenter-super-invar",
    "where": "Type analysis table, page 1 (nominal values, weight %); UNS K93500 on the same page under Associated specifications"
  },
  "tags": {
    "environments": [],
    "stresses": [
      "extreme-cold"
    ],
    "applications": [
      "optics-and-cameras",
      "electronics-and-chips"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "value": 8150,
      "bound": "exact",
      "unit": "kg/m3",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "unit_in_source": "8150 kg/cu m"
      },
      "method": "Value printed in a supplier technical data table",
      "status": "ground",
      "source": "hightempmetals-super-invar",
      "where": "Physical Properties table, row Density, metric line",
      "source_detail": {
        "title": "Hi-Temp Metals: Super Invar 32-5 technical data",
        "id": "Hi-Temp Metals technical data page, Super Invar 32-5",
        "url": "https://www.hightempmetals.com/techdata/hitempSuperInvardata.php",
        "kind": "web",
        "license": "Supplier page, cited not reproduced"
      }
    },
    {
      "benchmark": "density",
      "value": 0.294,
      "bound": "exact",
      "unit": "lb/in3",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "unit_in_source": "0.2940 lb/in3, English Units column"
      },
      "method": "Value printed in the manufacturer's physical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Physical properties table (page 2), row DENSITY, English Units column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "specific_gravity",
      "label": "Specific gravity (custom name, not in property-canon)",
      "value": 8.15,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "printed_in": "English and metric columns, both printed as 8.15"
      },
      "method": "Value printed in the manufacturer's physical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Physical properties table (page 2), row SPECIFIC GRAVITY",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "value": 0.63,
      "bound": "exact",
      "unit": "ppm/°C",
      "scope": "material",
      "conditions": {
        "temperature_range": "-55 to 95 °C",
        "basis": "mean coefficient of thermal expansion",
        "unit_in_source": "0.63 under the column heading 10(-6)/°C"
      },
      "method": "Value printed in a supplier technical data table",
      "status": "ground",
      "source": "hightempmetals-super-invar",
      "where": "Physical Properties table, row Mean coefficient of thermal expansion, 10(-6)/°C line for -55 to 95°C",
      "source_detail": {
        "title": "Hi-Temp Metals: Super Invar 32-5 technical data",
        "id": "Hi-Temp Metals technical data page, Super Invar 32-5",
        "url": "https://www.hightempmetals.com/techdata/hitempSuperInvardata.php",
        "kind": "web",
        "license": "Supplier page, cited not reproduced"
      }
    },
    {
      "benchmark": "poissons_ratio",
      "value": 0.23,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "basis": "printed with no unit"
      },
      "method": "Value printed in the manufacturer's physical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Physical properties table (page 2), row POISSON'S RATIO, English Units column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "value": 481.3,
      "bound": "exact",
      "unit": "ohm-cir-mil/ft",
      "scope": "material",
      "conditions": {
        "temperature": "73 °F (23 °C)"
      },
      "method": "Value printed in the manufacturer's physical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Physical properties table (page 2), row ELECTRICAL RESISTIVITY, 73°F (23°C) line",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "value": 80,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "temperature": "room temperature (RT), as printed"
      },
      "method": "Value printed in a supplier technical data table",
      "status": "ground",
      "source": "hightempmetals-super-invar",
      "where": "Physical Properties table, row Electrical resistivity (RT)",
      "source_detail": {
        "title": "Hi-Temp Metals: Super Invar 32-5 technical data",
        "id": "Hi-Temp Metals technical data page, Super Invar 32-5",
        "url": "https://www.hightempmetals.com/techdata/hitempSuperInvardata.php",
        "kind": "web",
        "license": "Supplier page, cited not reproduced"
      }
    },
    {
      "benchmark": "martensite_start",
      "label": "Martensite start temperature (custom name, not in property-canon)",
      "value": -80,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "printed_as": "-112 °F and -80 °C"
      },
      "method": "Value printed in the manufacturer's physical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Physical properties table (page 2), row MARTENSITE START, metric column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 276,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "heat_treatment": "annealed",
        "basis": "typical mechanical properties table, 0.2% yield"
      },
      "method": "Typical value printed in the manufacturer's mechanical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Typical mechanical properties table (page 3), row Annealed, 0.2% YIELD STRENGTH, MPa column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 276,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "heat_treatment": "cold worked",
        "basis": "typical mechanical properties table, 0.2% yield"
      },
      "method": "Typical value printed in the manufacturer's mechanical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Typical mechanical properties table (page 3), row Cold worked, 0.2% YIELD STRENGTH, MPa column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "value": 483,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "heat_treatment": "annealed",
        "basis": "typical mechanical properties table"
      },
      "method": "Typical value printed in the manufacturer's mechanical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Typical mechanical properties table (page 3), row Annealed, ULTIMATE TENSILE STRENGTH, MPa column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "value": 483,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "heat_treatment": "cold worked",
        "basis": "typical mechanical properties table"
      },
      "method": "Typical value printed in the manufacturer's mechanical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Typical mechanical properties table (page 3), row Cold worked, ULTIMATE TENSILE STRENGTH, MPa column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "value": 40,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "heat_treatment": "annealed",
        "gauge": "2 in (50.8 mm)",
        "basis": "typical mechanical properties table"
      },
      "method": "Typical value printed in the manufacturer's mechanical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Typical mechanical properties table (page 3), row Annealed, ELONGATION IN 2 IN (50.8 MM) column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "value": 40,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "heat_treatment": "cold worked",
        "gauge": "2 in (50.8 mm)",
        "basis": "typical mechanical properties table"
      },
      "method": "Typical value printed in the manufacturer's mechanical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Typical mechanical properties table (page 3), row Cold worked, ELONGATION IN 2 IN (50.8 MM) column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_b",
      "label": "Hardness, Rockwell B (custom name, not in property-canon)",
      "value": 75,
      "bound": "exact",
      "unit": "HRB",
      "scope": "material",
      "conditions": {
        "heat_treatment": "annealed",
        "basis": "typical mechanical properties table"
      },
      "method": "Typical value printed in the manufacturer's mechanical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Typical mechanical properties table (page 3), row Annealed, HARDNESS HRB column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_b",
      "label": "Hardness, Rockwell B (custom name, not in property-canon)",
      "value": 90,
      "bound": "exact",
      "unit": "HRB",
      "scope": "material",
      "conditions": {
        "heat_treatment": "cold worked",
        "basis": "typical mechanical properties table"
      },
      "method": "Typical value printed in the manufacturer's mechanical properties table",
      "status": "ground",
      "source": "carpenter-super-invar",
      "where": "Typical mechanical properties table (page 3), row Cold worked, HARDNESS HRB column",
      "source_detail": {
        "title": "Carpenter Technology: Super Invar 32-5 data sheet",
        "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
        "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet, cited not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Heat treatment at or above about 1000 °F (538 °C)",
      "headline": "Super Invar 32-5 oxidises readily above about 1000 °F (538 °C), so heat treatment needs a protective atmosphere.",
      "effect": "Carpenter says the alloy oxidises readily at heat-treating temperatures above about 1000 °F (538 °C) and recommends vacuum, hydrogen, dissociated ammonia or inert gases.",
      "rating": "moderate",
      "conditions": {
        "process": "heat treatment at or above about 1000 °F (538 °C)"
      },
      "source": "carpenter-super-invar",
      "where": "Heat treatment section (page 3), paragraph on protective environments"
    },
    {
      "environment": "Forging furnace with a long soak",
      "headline": "A long soak in the forging furnace can leave a checked surface.",
      "effect": "Carpenter says long soaking may give a checked surface from oxygen and sulfur contamination, and suggests forging at 2000/2150 °F (1093/1177 °C).",
      "rating": "moderate",
      "conditions": {
        "process": "forging"
      },
      "source": "carpenter-super-invar",
      "where": "Workability, Forging paragraph (page 4)"
    },
    {
      "environment": "Humid air and corrosion protection (no test of Super Invar 32-5 read)",
      "headline": "No humidity or salt-spray test of Super Invar 32-5 was read; the datasheet names plating and zinc coating as the usual finishes.",
      "effect": "Carpenter says the alloy can be chromium, cadmium and nickel plated or zinc coated by the usual methods used for ferrous alloys. No corrosion rate or humidity rating is printed for the bare alloy.",
      "rating": "unknown",
      "conditions": {
        "basis": "datasheet statement on finishes; no corrosion test data"
      },
      "source": "carpenter-super-invar",
      "where": "Workability, Plating paragraph (page 4)"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Cobalt is the main hazard in this alloy. PubChem's aggregation of ECHA C&L notifications for cobalt gives H317 (more than 99.9 %, may cause an allergic skin reaction), H334 (more than 99.9 %, may cause allergy or asthma symptoms if inhaled), H341 (65.8 %), H350 (64.5 %) and H360F (61.6 %). These are ratios for the element, not for Super Invar 32-5 itself.\n",
        "ghs": [
          "H317",
          "H334",
          "H341",
          "H350",
          "H360F"
        ],
        "source": "pubchem-cobalt",
        "where": "Safety and Hazards, GHS Classification (CID 104730), aggregated ECHA C&L notifications"
      },
      {
        "text": "Nickel (32.00 % of the alloy) is also a sensitiser. PubChem's aggregation of ECHA C&L notifications for nickel gives H317 for 99.9 % of reports, H372 (damage to organs through prolonged or repeated exposure) for 99.7 %, and H351 (suspected of causing cancer) for 72.9 %.\n",
        "ghs": [
          "H317",
          "H372",
          "H351"
        ],
        "source": "pubchem-nickel",
        "where": "Safety and Hazards, GHS Classification (CID 935), aggregated ECHA C&L notifications"
      }
    ],
    "failure_risks": [
      {
        "mode": "Dimensional drift after fabrication",
        "trigger": "Machining, forming or deep drawing introduces stresses",
        "consequence": "Carpenter says fabricating stresses promote variation in thermal expansion behaviour, so parts should be heat treated at or as close to finish size as possible.",
        "severity": "moderate",
        "source": "carpenter-super-invar",
        "where": "Heat treatment section (page 3), first paragraph"
      },
      {
        "mode": "Transformation at low temperature",
        "trigger": "Service below -67 °F (-55 °C)",
        "consequence": "Carpenter gives austenite stability to service temperatures of at least -67 °F (-55 °C) and prints martensite start at -112 °F (-80 °C); the datasheet gives no expansion values below -67 °F (-55 °C).",
        "severity": "moderate",
        "source": "carpenter-super-invar",
        "where": "Description (page 1) and Physical properties table (page 2), row MARTENSITE START"
      },
      {
        "mode": "Checked surface from furnace soaking",
        "trigger": "Long soak in a forging furnace",
        "consequence": "Carpenter says a long soaking time may give a checked surface from oxygen and sulfur contamination.",
        "severity": "moderate",
        "source": "carpenter-super-invar",
        "where": "Workability, Forging paragraph (page 4)"
      },
      {
        "mode": "Grain boundary embrittlement after machining",
        "trigger": "Residual sulfur left on machined parts",
        "consequence": "Carpenter says residual sulfur can cause grain boundary embrittlement, so parts should be degreased and cleaned as soon after machining as possible.",
        "severity": "moderate",
        "source": "carpenter-super-invar",
        "where": "Machinability, additional notes (page 4)"
      }
    ],
    "side_effects": [
      {
        "text": "Machined chips are gummy and stringy, so the alloy is somewhat difficult to machine.",
        "affects": "Machining operations",
        "source": "carpenter-super-invar",
        "where": "Machinability paragraph (page 4)"
      }
    ],
    "handling": [
      {
        "text": "Heat-treat before final machining: heat to 1550 °F (843 °C) for 1 hour, water quench, stress-relieve at 600 °F (316 °C) for 1 hour, air cool, then age at 200 °F (93 °C) for 24 hours and air cool.",
        "source": "carpenter-super-invar",
        "where": "Heat treatment, heat treating for lowest thermal expansion (page 3)"
      },
      {
        "text": "Above about 1000 °F (538 °C), heat-treat in a protective environment such as vacuum, hydrogen, dissociated ammonia or inert gas.",
        "source": "carpenter-super-invar",
        "where": "Heat treatment section (page 3)"
      },
      {
        "text": "Forge at 2000/2150 °F (1093/1177 °C), heat rapidly and avoid soaking in the forging furnace.",
        "source": "carpenter-super-invar",
        "where": "Workability, Forging paragraph (page 4)"
      },
      {
        "text": "Degrease and clean machined parts as soon as possible after machining to remove residual sulfur.",
        "source": "carpenter-super-invar",
        "where": "Machinability, additional notes (page 4)"
      }
    ],
    "mitigations": [
      {
        "text": "Heat-treat parts at or as close to finish size as possible, using the schedule under handling.",
        "source": "carpenter-super-invar",
        "where": "Heat treatment section (page 3)"
      }
    ]
  },
  "uses": [
    {
      "application": "optics-and-cameras",
      "device": "Optical and laser systems",
      "example": "Carpenter lists optical and laser systems as an application of Super Invar 32-5 on its datasheet.",
      "source": "carpenter-super-invar",
      "where": "Description (page 1), Applications list"
    },
    {
      "application": "electronics-and-chips",
      "device": "Semiconductor components",
      "example": "Carpenter lists semiconductor components among the applications of Super Invar 32-5 on its datasheet.",
      "source": "carpenter-super-invar",
      "where": "Description (page 1), Applications list"
    },
    {
      "application": "electronics-and-chips",
      "device": "Wave guide tubes and other low-expansion glass or quartz assemblies",
      "example": "Carpenter lists wave guide tubes and other systems with low expansion glass or quartz assemblies as applications.",
      "source": "carpenter-super-invar",
      "where": "Description (page 1), Applications list"
    }
  ],
  "supply": [
    {
      "subject": "Nickel (32.00 % 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
        },
        {
          "country": "Canada",
          "share_percent": 3.6,
          "year": 2025
        },
        {
          "country": "New Caledonia",
          "share_percent": 3.6,
          "year": 2025
        },
        {
          "country": "China",
          "share_percent": 3.1,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS MCS 2026 nickel chapter: the Executive Order 14285 text names critical minerals such as nickel",
          "listed": true
        }
      ],
      "recycling": "USGS: in 2025 nickel recovered from scrap accounted for approximately 60% of apparent consumption.",
      "substitutes": [
        "USGS: low-nickel, duplex or ultrahigh-chromium stainless steels have been substituted for austenitic grades in construction; titanium alloys can substitute for nickel-base alloys in corrosive environments."
      ],
      "source": "usgs-nickel-2026",
      "where": "World Mine Production and Reserves table, 2025e column (world total 3,900,000 t); shares computed by Space Mushroom from that table; Recycling and Substitutes paragraphs; critical-minerals wording in the Events section"
    },
    {
      "subject": "Cobalt (5.50 % of the alloy)",
      "producers": [
        {
          "country": "Congo (Kinshasa)",
          "share_percent": 73,
          "year": 2025
        },
        {
          "country": "Indonesia",
          "share_percent": 14,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: in 2025, cobalt content of purchased scrap represented 25% of estimated cobalt consumption.",
      "substitutes": [
        "USGS: depending on the application, substitution for cobalt could result in a loss in product performance or increased cost."
      ],
      "source": "usgs-cobalt-2026",
      "where": "Events, Trends, and Issues paragraph (shares printed as 73% and 14% of world total); Recycling line; Substitutes paragraph; World Mine Production table, 2025 column (world total 310,000 t)"
    },
    {
      "subject": "Iron (balance of the alloy)",
      "producers": [
        {
          "country": "Australia",
          "share_percent": 37.7,
          "year": 2025
        },
        {
          "country": "Brazil",
          "share_percent": 16.2,
          "year": 2025
        },
        {
          "country": "India",
          "share_percent": 11.9,
          "year": 2025
        },
        {
          "country": "China",
          "share_percent": 11.2,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: none for iron ore; see the separate Iron and Steel Scrap chapter.",
      "substitutes": [],
      "source": "usgs-iron-ore-2026",
      "where": "World Mine Production and Reserves table, 2025e usable-ore column (world total 2,600,000 thousand t); shares computed by Space Mushroom from that table; Recycling line"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Carpenter Technology Super Invar 32-5 data sheet (ASTM F1684, UNS K93500)",
      "type": "datasheet",
      "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf"
    },
    {
      "title": "Hi-Temp Metals: Super Invar 32-5 technical data",
      "type": "datasheet",
      "url": "https://www.hightempmetals.com/techdata/hitempSuperInvardata.php"
    },
    {
      "title": "Outer Planets Mission Television Subsystem Optics Study, final report, 28 July 1972 (NASA NTRS 19720025731)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/19720025731/downloads/19720025731.pdf",
      "year": 1972
    },
    {
      "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: Cobalt",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Iron ore",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-ore.pdf",
      "year": 2026
    },
    {
      "title": "PubChem: Cobalt (CID 104730)",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/104730",
      "year": 2026
    },
    {
      "title": "PubChem: Nickel (CID 935)",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/935",
      "year": 2026
    },
    {
      "title": "PubChem: Iron (CID 23925)",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23925",
      "year": 2026
    }
  ],
  "gaps": [
    "Not found in the datasheet and supplier pages read in this run: melting point, Curie temperature, thermal conductivity and specific heat. Nothing was entered for them.",
    "Carpenter gives the mean CTE as 0.350 x 10-6 in/in/°F for -67 to 203 °F (-55 to 95 °C), with the exponent in the value cell. Under the exponent rule it was left out; the expansion value recorded is the Hi-Temp Metals figure of 0.63 ppm/°C from -55 to 95 °C.",
    "Elastic modulus was left out. Hi-Temp Metals prints 144 under the unit x 10(6) MPa beside 21 under x 10(6) psi, which do not agree on the printed exponent. Carpenter prints 21.0 x 103 ksi with the exponent in the value. No modulus was entered rather than choose a unit.",
    "No corrosion rate, humidity exposure or salt-spray result for Super Invar 32-5 was read. The corrosion entries rest on the heat-treatment oxidation statement, the forging soak statement and the plating statement.",
    "The two typical analyses disagree: Hi-Temp Metals prints nickel 31.75 and cobalt 5.36 (weight units not printed), against Carpenter's nominal 32.00 and 5.50 %. The Carpenter nominal values are used in the record and both are noted here.",
    "Carpenter's description gives the -67/203 °F (-55/95 °C) range as the one for which the alloy's thermal expansion is less than Invar 36's. Carpenter prints no Invar 36 value, so no Invar 36 number is recorded here.",
    "Custom benchmark names not in property-canon.yaml: specific_gravity, martensite_start and hardness_rockwell_b (Rockwell B values 75 and 90 HRB, annealed and cold worked).",
    "The taxonomy has no controlled-expansion-alloy type, so this profile is filed under nickel-superalloys, as Invar 36 is. Super Invar is not a superalloy.",
    "Cobalt's critical-mineral status was not read: the USGS 2025 critical minerals list was not fetched in this run. The nickel critical-mineral entry cites the wording in the USGS nickel chapter.",
    "No vacuum outgassing, radiation, atomic-oxygen or thermal-vacuum data for Super Invar 32-5 were read. The only space source is the 1972 JPL/Itek study, a design report, which says Super-Invar was not used because its expansion properties were unstable over long periods of time.",
    "Atomic weights are given for iron, nickel and cobalt only. Manganese, silicon and carbon appear in the type analysis without atomic weights.",
    "No cryogenic expansion data below -55 °C were read.",
    "No cost or lead-time data were read."
  ],
  "story": {
    "why": "Super Invar 32-5 is used where a metal must keep its length near room temperature. Hi-Temp Metals prints a mean coefficient of thermal expansion of 0.63 ppm/°C from -55 to 95 °C and a density of 8150 kg/m3. The cost is strength: the typical yield strength is 276 MPa and the typical tensile strength is 483 MPa, both in the annealed condition.\n",
    "uses": [
      {
        "where": "Optical and laser systems",
        "line": "Carpenter lists optical and laser systems among the applications of Super Invar 32-5 on its datasheet."
      },
      {
        "where": "Semiconductor components and wave guide tubes",
        "line": "Carpenter lists semiconductor components, wave guide tubes and other systems with low expansion glass or quartz assemblies."
      }
    ],
    "can_do": [
      {
        "label": "Expansion",
        "line": "0.63 ppm/°C from -55 to 95 °C, as a mean coefficient (Hi-Temp Metals).",
        "benchmark": "cte",
        "scope": "material"
      },
      {
        "label": "Strength",
        "line": "276 MPa yield and 483 MPa tensile in the annealed condition (Carpenter typical values).",
        "benchmark": "yield_strength",
        "scope": "material"
      },
      {
        "label": "Ductility",
        "line": "40 % elongation in 2 in (50.8 mm) in the annealed condition (Carpenter typical value).",
        "benchmark": "elongation",
        "scope": "material"
      },
      {
        "label": "Density",
        "line": "8150 kg/m3 (Hi-Temp Metals).",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Resistivity",
        "line": "481.3 ohm-cir-mil/ft at 73 °F (23 °C) (Carpenter).",
        "benchmark": "electrical_resistivity",
        "scope": "material"
      }
    ],
    "compare": "Carpenter says the thermal expansion of Super Invar 32-5 is less than that of Invar 36 over -67/203 °F (-55/95 °C). The datasheet prints no Invar 36 value, so that comparison is qualitative here. Against other low-expansion metals, the figures to weigh are the 0.63 ppm/°C mean coefficient and the 276 MPa annealed yield strength for this grade.\n",
    "compare_rows": [
      {
        "label": "Thermal expansion",
        "benchmark": "cte",
        "scope": "material"
      },
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Strength",
        "benchmark": "yield_strength",
        "scope": "material"
      }
    ],
    "handling": [
      "Heat-treat before final machining: heat to 1550 °F (843 °C) for 1 hour, water quench, stress-relieve at 600 °F (316 °C) for 1 hour, air cool, then age at 200 °F (93 °C) for 24 hours.",
      "Above about 1000 °F (538 °C), use a protective atmosphere such as vacuum, hydrogen, dissociated ammonia or inert gas.",
      "Forge at 2000/2150 °F (1093/1177 °C) and do not soak long in the furnace, which can check the surface.",
      "Degrease and clean machined parts soon after machining to remove residual sulfur, which can cause grain boundary embrittlement."
    ],
    "good_for": [
      "Parts that must hold a length near room temperature: mean coefficient 0.63 ppm/°C from -55 to 95 °C.",
      "Optical and laser systems, semiconductor components and wave guide tubes, per Carpenter's applications list.",
      "Assemblies that must match low expansion glass or quartz, per Carpenter."
    ],
    "watch_out": [
      "Long-term expansion drift: the 1972 JPL/Itek study rejected Super-Invar for this reason.",
      "Cold work changes the expansion, so heat-treat parts at or as close to finish size as possible.",
      "No corrosion rate or humidity test was read; the datasheet lists plating and zinc coating as the usual finishes."
    ],
    "verdict": "Super Invar 32-5 suits parts that must hold a length near room temperature, where Carpenter says its expansion is lower than Invar 36's. Design with its 0.63 ppm/°C mean coefficient and 276 MPa annealed yield strength, but note that the 1972 JPL study rejected it for long-term expansion stability, and that no corrosion rate was found.\n",
    "recipe": {
      "line": "Super Invar 32-5 is a magnetic, austenitic solid solution of iron, nickel and cobalt. Carpenter's nominal type analysis is 32.00 % nickel, 5.50 % cobalt, 0.40 % manganese, 0.25 % silicon and 0.02 % carbon, with iron as the balance. It is supplied as bar, billet, strip and wire.\n",
      "parts": [
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "Balance of the alloy. Carpenter describes the alloy as magnetic and austenitic.",
          "share_note": "balance",
          "source": "pubchem-iron",
          "where": "Elemental iron, PubChem CID 23925 (molecular weight read there, not entered)"
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Carpenter says the alloy is designed to give minimum thermal expansion at room temperatures, and nickel is the main element in the type analysis.",
          "share_percent": 32,
          "share_note": "wt%, nominal 32.00",
          "source": "carpenter-super-invar",
          "where": "Type analysis table, Nickel 32.00 %; elemental nickel, PubChem CID 935 (molecular weight read there, not entered)"
        },
        {
          "name": "Cobalt",
          "symbol": "Co",
          "role": "Named in the type analysis. The datasheet does not state its role.",
          "share_percent": 5.5,
          "share_note": "wt%, nominal 5.50",
          "source": "carpenter-super-invar",
          "where": "Type analysis table, Cobalt 5.50 %; elemental cobalt, PubChem CID 104730 (molecular weight read there, not entered)"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The alloy is mostly iron, but its cobalt and nickel are the health hazards, and machining produces dust and chips that carry them.",
        "points": [
          {
            "label": "Skin",
            "line": "PubChem's aggregated reports give H317 (may cause an allergic skin reaction) for more than 99.9 % of cobalt reports and for 99.9 % of nickel reports."
          },
          {
            "label": "Breathing",
            "line": "Cobalt is H334 (may cause allergy or asthma symptoms if inhaled) for more than 99.9 % of reports."
          }
        ],
        "level": 1,
        "verdict": "Cobalt and nickel are sensitisers; control dust"
      },
      {
        "title": "In service",
        "lead": "Its low expansion depends on stress relief after fabrication, and the alloy oxidises during heat treatment.",
        "points": [
          {
            "label": "Dimensional drift",
            "line": "Fabricating stresses change the expansion behaviour, so Carpenter says to heat-treat at or as close to finish size as possible."
          },
          {
            "label": "Oxidation",
            "line": "Above about 1000 °F (538 °C) the alloy oxidises readily, so heat treatment needs a protective atmosphere."
          }
        ],
        "level": 2,
        "verdict": "Stable only if heat-treated near finish size"
      },
      {
        "title": "In space",
        "lead": "The space record here is a 1972 design study. No flight or test data for Super Invar 32-5 were read.",
        "points": [
          {
            "label": "What the report says",
            "line": "The 1972 JPL/Itek study did not use Super-Invar, because the expansion properties of the material were unstable over long periods of time."
          },
          {
            "label": "What is missing",
            "line": "No thermal-vacuum, outgassing or radiation test of Super Invar 32-5 was read."
          }
        ],
        "level": 1,
        "verdict": "Rejected for a 1972 telescope design"
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 16,
    "unreachable": 0,
    "caveats": 4,
    "note": "Values were read by an AI assistant on 2026-11-01 from the Carpenter Technology Super Invar 32-5 datasheet (PDF, converted with pdftotext), the Hi-Temp Metals technical data page, the USGS Mineral Commodity Summaries 2026 chapters for nickel, cobalt and iron ore (PDF), the 1972 JPL/Itek optics study (NASA NTRS PDF) and PubChem records. Caveats: the strengths and hardness are typical values of one manufacturer; the elastic modulus and the Carpenter expansion value are left out under the exponent rule; the specific gravity, martensite start and hardness names are custom; the space use comes from a 1972 design report rather than a test.\n"
  },
  "sources": {
    "carpenter-super-invar": {
      "title": "Carpenter Technology: Super Invar 32-5 data sheet",
      "id": "Carpenter Technology data sheet, Super Invar 32-5 (ASTM F1684, UNS K93500)",
      "url": "https://www.carpentertechnology.com/hubfs/7407324/Material%20Saftey%20Data%20Sheets/Super%20Invar%2032-5.pdf",
      "kind": "datasheet",
      "license": "Manufacturer datasheet, cited not reproduced"
    },
    "hightempmetals-super-invar": {
      "title": "Hi-Temp Metals: Super Invar 32-5 technical data",
      "id": "Hi-Temp Metals technical data page, Super Invar 32-5",
      "url": "https://www.hightempmetals.com/techdata/hitempSuperInvardata.php",
      "kind": "web",
      "license": "Supplier page, cited not reproduced"
    },
    "usgs-nickel-2026": {
      "title": "Mineral Commodity Summaries 2026: Nickel",
      "id": "USGS MCS 2026, nickel",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf",
      "year": 2026,
      "kind": "report",
      "license": "USGS public domain"
    },
    "usgs-cobalt-2026": {
      "title": "Mineral Commodity Summaries 2026: Cobalt",
      "id": "USGS MCS 2026, cobalt",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf",
      "year": 2026,
      "kind": "report",
      "license": "USGS public domain"
    },
    "usgs-iron-ore-2026": {
      "title": "Mineral Commodity Summaries 2026: Iron ore",
      "id": "USGS MCS 2026, iron ore",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-ore.pdf",
      "year": 2026,
      "kind": "report",
      "license": "USGS public domain"
    },
    "ntrs-19720025731": {
      "title": "Outer Planets Mission Television Subsystem Optics Study, final report, 28 July 1972",
      "id": "NASA NTRS 19720025731 (Itek 72-9320-1, for JPL)",
      "url": "https://ntrs.nasa.gov/api/citations/19720025731/downloads/19720025731.pdf",
      "year": 1972,
      "kind": "report",
      "license": "NASA NTRS public document"
    },
    "pubchem-cobalt": {
      "title": "PubChem: Cobalt (CID 104730), Safety and Hazards",
      "id": "PubChem CID 104730",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/104730",
      "year": 2026,
      "kind": "database",
      "license": "PubChem, U.S. National Library of Medicine"
    },
    "pubchem-nickel": {
      "title": "PubChem: Nickel (CID 935), Safety and Hazards",
      "id": "PubChem CID 935",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/935",
      "year": 2026,
      "kind": "database",
      "license": "PubChem, U.S. National Library of Medicine"
    },
    "pubchem-iron": {
      "title": "PubChem: Iron (CID 23925), molecular weight",
      "id": "PubChem CID 23925",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23925",
      "year": 2026,
      "kind": "database",
      "license": "PubChem, U.S. National Library of Medicine"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/super-invar-32-5/"
}