{
  "spore": "profile",
  "id": "stainless-347",
  "spore_version": "0.2",
  "family": "stainless-austenitic",
  "name": "AISI 347 stainless steel",
  "abbreviation": "347",
  "role": "Niobium-stabilised austenitic stainless steel for welded, hot service",
  "category": "metals",
  "type": "steels-and-stainless",
  "summary": "AISI 347 (UNS S34700, EN 1.4550) is an austenitic stainless steel with 17 to 19 % chromium and 9 to 13 % nickel, stabilised with niobium (columbium) so that it resists intergranular attack after exposure in the chromium-carbide range of 427 to 816 °C. The UPMET datasheet prints a density of 7.96 g/cm3 for grade 347 and a melting range of 1398 to 1446 °C. The Combmet datasheet gives a modulus of 193 GPa at 20 °C and typical annealed values of 640 MPa tensile strength and 250 MPa yield. The Smith datasheet prints a maximum use temperature in air of 800 °C.\n",
  "best_for": "Welded hot-service parts that cannot be re-annealed afterwards: niobium stabilisation resists intergranular attack, and the grade is rated to 800 °C in air",
  "weakest_at": "Strength when hot: tensile strength falls from 93.3 ksi at 68 °F to 69.5 ksi at 800 °F (Rolled Alloys), and no vacuum, radiation or atomic-oxygen data were found",
  "identity": {
    "formula": "Fe-based austenitic alloy: Fe balance, Cr 17.00 to 19.00 %, Ni 9.00 to 13.00 % (9.00 to 12.00 % in UPMET and Combmet), C 0.08 % maximum, Mn 2.00 % maximum, S 0.03 % maximum, Nb plus Ta at 10 x C minimum and 1.00 % maximum (ASTM A240 limits)",
    "designations": [
      {
        "system": "UNS",
        "code": "S34700",
        "source": "combmet347",
        "where": "Header, UNS: S34700"
      },
      {
        "system": "EN",
        "code": "1.4550",
        "source": "combmet347",
        "where": "Header, EN-DIN: 1.4550"
      },
      {
        "system": "EN name",
        "code": "X6CrNiNb18-10",
        "source": "alfa347",
        "where": "Title line and header, X6CrNiNb18-10, 1.4550 EN 10088-2:2014"
      },
      {
        "system": "AISI",
        "code": "347",
        "source": "alfa347",
        "where": "Title line and header, AISI 347"
      },
      {
        "system": "JIS",
        "code": "SUS347",
        "source": "tachart347",
        "where": "Alias heading, JIS: SUS347"
      },
      {
        "system": "ASTM",
        "code": "A240",
        "note": "plate, sheet and strip",
        "source": "aalco347",
        "where": "Spec line, Spec: ASTM A240"
      },
      {
        "system": "ASTM",
        "code": "A269",
        "note": "tube",
        "source": "finetubes347",
        "where": "Designations block, ASTM A269"
      },
      {
        "system": "ASTM",
        "code": "A312",
        "note": "pipe",
        "source": "finetubes347",
        "where": "Designations block, ASTM A312"
      },
      {
        "system": "ASTM",
        "code": "TP347",
        "note": "tube and pipe grade",
        "source": "alfa347",
        "where": "Header list, TP347"
      },
      {
        "system": "AMS",
        "code": "5512",
        "note": "sheet, coil and bar",
        "source": "upmet347",
        "where": "Header line, AMS 5512 / AMS 5646 / UNS S34700"
      },
      {
        "system": "AMS",
        "code": "5646",
        "source": "upmet347",
        "where": "Header line, AMS 5512 / AMS 5646 / UNS S34700"
      },
      {
        "system": "ASME",
        "code": "SA-240",
        "source": "rolled347",
        "where": "Specifications block, ASME: SA-240"
      },
      {
        "system": "Trade name",
        "code": "Alloy 347",
        "source": "combmet347",
        "where": "Document title, Alloy 347 Stainless Steel"
      },
      {
        "system": "Trade name",
        "code": "Type 347",
        "source": "rolled347",
        "where": "Product description paragraph, Type 347 stainless steel"
      }
    ],
    "source": "aalco347",
    "where": "Chemical composition table, ASTM A240 sheet limits (Aalco datasheet); Nb plus Ta row from the UPMET chemical composition table"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "thermal-control",
      "structures"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, grade 347",
      "value": 7.96,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "347",
        "temperature": "not stated in the table",
        "unit_in_source": "0.288 lb/in3"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "upmet347",
      "where": "Physical Properties table, row 347, column Density g/cm3",
      "source_detail": {
        "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
        "id": "AMS 5512, AMS 5646, UNS S34700",
        "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting range, grade 347",
      "value": 1398,
      "value_high": 1446,
      "bound": "range",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "347",
        "unit_in_source": "2550-2635 °F",
        "pressure": "not stated"
      },
      "method": "Melting range printed in a manufacturer datasheet",
      "status": "ground",
      "source": "upmet347",
      "where": "Physical Properties table, row 347, column Melting Range °C",
      "source_detail": {
        "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
        "id": "AMS 5512, AMS 5646, UNS S34700",
        "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity in tension, 20 °C",
      "value": 193,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "unit_in_source": "193 x 10^3 MPa (28.0 x 10^3 ksi at 70 °F)"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "combmet347",
      "where": "Physical Properties table, column At 20oC, row Modulus of Elasticity (E)",
      "source_detail": {
        "title": "Alloy 347 Stainless Steel Data Sheet, Combined Metals Company (REV 2024 01 16)",
        "id": "UNS S34700, EN-DIN 1.4550; typical values based on ATI source, ASTM A240",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/Alloy-347-Stainless-Steel-Data-Sheet-2024-01-16.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "Distributor datasheet, reference only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity at 20 °C",
      "value": 16.3,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "unit_in_source": "9.5 Btu-in./ft.2 hr.-oF at 70 °F"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "combmet347",
      "where": "Physical Properties table, column At 20oC, row Thermal Conductivity",
      "source_detail": {
        "title": "Alloy 347 Stainless Steel Data Sheet, Combined Metals Company (REV 2024 01 16)",
        "id": "UNS S34700, EN-DIN 1.4550; typical values based on ATI source, ASTM A240",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/Alloy-347-Stainless-Steel-Data-Sheet-2024-01-16.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "Distributor datasheet, reference only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, 20 to 500 °C",
      "value": 21.4,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "temperature_range": "20 to 500 °C",
        "unit_in_source": "147.7 Btu-in/hr-ft2-°F"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "note": "The UPMET thermal table is not labelled by grade; the datasheet title is for 347 sheet, coil and bar.",
      "source": "upmet347",
      "where": "Thermal Conductivity table, row 20-500 (68-932 °F), column W/m·K",
      "source_detail": {
        "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
        "id": "AMS 5512, AMS 5646, UNS S34700",
        "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat capacity, 0 to 100 °C",
      "value": 500,
      "bound": "exact",
      "unit": "J/(kg·K)",
      "scope": "material",
      "conditions": {
        "temperature_range": "0 to 100 °C",
        "unit_in_source": "0.12 Btu/lb·°F"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "note": "The UPMET specific heat table is not labelled by grade; the datasheet title is for 347 sheet, coil and bar.",
      "source": "upmet347",
      "where": "Specific Heat table, row 0-100 (32-212 °F), column J/kg K",
      "source_detail": {
        "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
        "id": "AMS 5512, AMS 5646, UNS S34700",
        "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity at 20 °C",
      "value": 72,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "unit_in_source": "28.4 µΩ·in at 70 °F"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "combmet347",
      "where": "Physical Properties table, column At 20oC, row Electrical Resistivity",
      "source_detail": {
        "title": "Alloy 347 Stainless Steel Data Sheet, Combined Metals Company (REV 2024 01 16)",
        "id": "UNS S34700, EN-DIN 1.4550; typical values based on ATI source, ASTM A240",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/Alloy-347-Stainless-Steel-Data-Sheet-2024-01-16.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "Distributor datasheet, reference only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity at 900 °C",
      "value": 126,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "temperature": "900 °C",
        "unit_in_source": "microhm·cm"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "note": "The UPMET resistivity table is not labelled by grade; the datasheet title is for 347 sheet, coil and bar.",
      "source": "upmet347",
      "where": "Electrical Resistivity table, row 900 (1652 °F), column microhm·cm",
      "source_detail": {
        "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
        "id": "AMS 5512, AMS 5646, UNS S34700",
        "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of linear thermal expansion, 20 to 100 °C",
      "value": 16.6,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "temperature_range": "20 to 100 °C",
        "unit_in_source": "16.6 x 10-6 cm/cm/°C (9.2 x 10-6 in/in/°F)"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "upmet347",
      "where": "Mean Coefficient of Linear Thermal Expansion table, row 20-100 (68-212 °F), column cm/cm/°C",
      "source_detail": {
        "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
        "id": "AMS 5512, AMS 5646, UNS S34700",
        "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of linear thermal expansion, 20 to 600 °C",
      "value": 18.9,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "temperature_range": "20 to 600 °C",
        "unit_in_source": "18.9 x 10-6 cm/cm/°C (10.5 x 10-6 in/in/°F)"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "upmet347",
      "where": "Mean Coefficient of Linear Thermal Expansion table, row 20-600 (68-912 °F), column cm/cm/°C",
      "source_detail": {
        "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
        "id": "AMS 5512, AMS 5646, UNS S34700",
        "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength 0.2 % offset, minimum, ASTM A240 sheet",
      "value": 205,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "spec": "ASTM A240",
        "form": "sheet",
        "measure": "0.2 % proof stress, minimum"
      },
      "method": "Minimum value printed in a supplier datasheet quoting ASTM A240",
      "status": "ground",
      "source": "aalco347",
      "where": "Mechanical Properties table, row Proof Stress, value 205 Min MPa",
      "source_detail": {
        "title": "Stainless Steel S34700 Sheet, Aalco datasheet (ASTM A240 limits)",
        "id": "Spec: ASTM A240",
        "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-S34700-Sheet_270.ashx",
        "kind": "datasheet",
        "license": "Distributor datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength 0.2 % offset, typical, annealed",
      "value": 250,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temper": "annealed",
        "basis": "typical values based on ATI source, ASTM A240",
        "unit_in_source": "37 ksi"
      },
      "method": "Typical value printed in a supplier datasheet",
      "status": "ground",
      "source": "combmet347",
      "where": "Typical Room Temperature Mechanical Properties table, row Annealed, column 0.2% YS",
      "source_detail": {
        "title": "Alloy 347 Stainless Steel Data Sheet, Combined Metals Company (REV 2024 01 16)",
        "id": "UNS S34700, EN-DIN 1.4550; typical values based on ATI source, ASTM A240",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/Alloy-347-Stainless-Steel-Data-Sheet-2024-01-16.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "Distributor datasheet, reference only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, minimum, ASTM A240 sheet",
      "value": 515,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "spec": "ASTM A240",
        "form": "sheet"
      },
      "method": "Minimum value printed in a supplier datasheet quoting ASTM A240",
      "status": "ground",
      "source": "aalco347",
      "where": "Mechanical Properties table, row Tensile Strength, value 515 Min MPa",
      "source_detail": {
        "title": "Stainless Steel S34700 Sheet, Aalco datasheet (ASTM A240 limits)",
        "id": "Spec: ASTM A240",
        "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-S34700-Sheet_270.ashx",
        "kind": "datasheet",
        "license": "Distributor datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, typical, annealed",
      "value": 640,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temper": "annealed",
        "basis": "typical values based on ATI source, ASTM A240",
        "unit_in_source": "93 ksi"
      },
      "method": "Typical value printed in a supplier datasheet",
      "status": "ground",
      "source": "combmet347",
      "where": "Typical Room Temperature Mechanical Properties table, row Annealed, column Tensile Strength (UTS)",
      "source_detail": {
        "title": "Alloy 347 Stainless Steel Data Sheet, Combined Metals Company (REV 2024 01 16)",
        "id": "UNS S34700, EN-DIN 1.4550; typical values based on ATI source, ASTM A240",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/Alloy-347-Stainless-Steel-Data-Sheet-2024-01-16.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "Distributor datasheet, reference only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength at 800 °F, typical",
      "value": 69.5,
      "bound": "exact",
      "unit": "ksi",
      "scope": "material",
      "conditions": {
        "temperature": "800 °F as printed (about 427 °C)",
        "basis": "typical tensile and impact properties",
        "form": "not stated"
      },
      "method": "Typical value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "rolled347",
      "where": "Typical Tensile and Impact Properties table, column 800, row Ultimate Tensile Strength, ksi",
      "source_detail": {
        "title": "Bulletin No. 147, 347/347H Data Sheet, Rolled Alloys (USe 03/21)",
        "id": "UNS S34700, S34709; AMS 5512; ASTM A240, A262; ASME SA-240",
        "url": "https://www.rolledalloys.ca/wp-content/uploads/347_stainless-steel-data-sheet-rolled-alloys.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, minimum, ASTM A240 sheet",
      "value": 40,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "spec": "ASTM A240",
        "form": "sheet",
        "gauge_length": "A50 mm"
      },
      "method": "Minimum value printed in a supplier datasheet quoting ASTM A240",
      "status": "ground",
      "source": "aalco347",
      "where": "Mechanical Properties table, row Elongation A50 mm, value 40 Min %",
      "source_detail": {
        "title": "Stainless Steel S34700 Sheet, Aalco datasheet (ASTM A240 limits)",
        "id": "Spec: ASTM A240",
        "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-S34700-Sheet_270.ashx",
        "kind": "datasheet",
        "license": "Distributor datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, typical, annealed",
      "value": 45,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temper": "annealed",
        "gauge_length": "2 in (50.8 mm)",
        "basis": "typical values based on ATI source, ASTM A240"
      },
      "method": "Typical value printed in a supplier datasheet",
      "status": "ground",
      "source": "combmet347",
      "where": "Typical Room Temperature Mechanical Properties table, row Annealed, column Elongation % in 2 in",
      "source_detail": {
        "title": "Alloy 347 Stainless Steel Data Sheet, Combined Metals Company (REV 2024 01 16)",
        "id": "UNS S34700, EN-DIN 1.4550; typical values based on ATI source, ASTM A240",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/Alloy-347-Stainless-Steel-Data-Sheet-2024-01-16.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "Distributor datasheet, reference only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Hardness, maximum, Brinell (plate)",
      "value": 201,
      "bound": "upper",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "product_form": "plate",
        "scale": "Brinell"
      },
      "method": "Maximum value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "upmet347",
      "where": "Mechanical Properties table, row Hardness Max., Brinell (Plate), column Type 347",
      "source_detail": {
        "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
        "id": "AMS 5512, AMS 5646, UNS S34700",
        "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Hardness, maximum, Rockwell B (sheet and strip)",
      "value": 92,
      "bound": "upper",
      "unit": "HRB",
      "scope": "material",
      "conditions": {
        "product_form": "sheet and strip",
        "scale": "Rockwell B"
      },
      "method": "Maximum value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "upmet347",
      "where": "Mechanical Properties table, row Hardness Max., RB (Sheet & Strip), column Type 347",
      "source_detail": {
        "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
        "id": "AMS 5512, AMS 5646, UNS S34700",
        "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Hardness, typical, annealed (HRBW)",
      "value": 84,
      "bound": "exact",
      "unit": "HRBW",
      "scope": "material",
      "conditions": {
        "temper": "annealed",
        "basis": "typical values based on ATI source, ASTM A240"
      },
      "method": "Typical value printed in a supplier datasheet",
      "status": "ground",
      "source": "combmet347",
      "where": "Typical Room Temperature Mechanical Properties table, row Annealed, column Hardness Rockwell",
      "source_detail": {
        "title": "Alloy 347 Stainless Steel Data Sheet, Combined Metals Company (REV 2024 01 16)",
        "id": "UNS S34700, EN-DIN 1.4550; typical values based on ATI source, ASTM A240",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/Alloy-347-Stainless-Steel-Data-Sheet-2024-01-16.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "Distributor datasheet, reference only (cited, not reproduced)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Maximum use temperature in air",
      "value": 800,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "environment": "air",
        "basis": "stated as the maximum use temperature, no duration given"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "smith347",
      "where": "Physical Properties table, row Maximum use temperature in air",
      "source_detail": {
        "title": "347 Stainless Technical Datasheet, Smiths Metal Centres (2023)",
        "url": "https://www.smithmetal.com/pdf/stainless/347-stainless.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "Distributor datasheet, approximate testing (cited, not reproduced)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Chromium-carbide sensitisation range, 427 to 816 °C (welding and stress relief)",
      "headline": "Niobium stabilisation keeps the grade resistant to intergranular corrosion after exposure in the chromium-carbide range.",
      "effect": "Combmet says the 347 alloys are stabilised by columbium and resist intergranular corrosion after exposure at 800 to 1500 °F (427 to 816 °C). Rolled Alloys says the grade has good resistance to intergranular corrosion in the as-welded condition.",
      "rating": "low",
      "conditions": {
        "basis": "datasheet statements; no corrosion rate printed",
        "stabiliser": "columbium (niobium)"
      },
      "source": "combmet347",
      "where": "Description paragraph of the Combmet datasheet"
    },
    {
      "environment": "Polythionic acid in oil refineries",
      "headline": "Type 347 resists polythionic acid stress corrosion cracking, a refinery hazard.",
      "effect": "Rolled Alloys says both 347 and 321 offer good resistance to polythionic acid stress corrosion cracking encountered in oil refineries. Smith says the alloy has good resistance to polythionic acid stress corrosion cracking and is useful around reactor plants.",
      "rating": "low",
      "conditions": {
        "basis": "datasheet statements; no test duration or concentration printed"
      },
      "source": "rolled347",
      "where": "Opening paragraph and Applications list of the Rolled Alloys datasheet"
    },
    {
      "environment": "Strongly oxidising service and high-temperature air",
      "headline": "Type 347 has slightly better corrosion resistance than Type 321 in strongly oxidising environments, and is useful to 1500 °F.",
      "effect": "Rolled Alloys says 347 has slightly improved corrosion resistance over type 321 in strongly oxidising environments, and that its high-temperature oxidation resistance is similar to 304 stainless steel. Smith prints a maximum use temperature in air of 800 °C.",
      "rating": "low",
      "conditions": {
        "basis": "datasheet statements; no oxidation rate printed"
      },
      "source": "rolled347",
      "where": "Opening paragraph of the Rolled Alloys datasheet; Smith Physical Properties table"
    },
    {
      "environment": "Chloride and general wet service",
      "headline": "Smith describes the grade as having excellent pitting resistance and good resistance to most chemicals.",
      "effect": "The Smith datasheet states excellent pitting resistance and good resistance to most chemicals, without a critical pitting temperature or a chloride limit.",
      "rating": "low",
      "conditions": {
        "basis": "general statement; no test data printed"
      },
      "source": "smith347",
      "where": "Corrosion resistance box of the Smith datasheet"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Uddeholm safety information sheet for steel articles, nickel entry: H317 May cause an allergic skin reaction. H351 Suspected of causing cancer by inhalation. H372 Causes damage to organs through prolonged or repeated exposure by inhalation. Signal word DANGER. The same sheet says massive steel products need no label, but dust and fumes from grinding, polishing, welding or cutting carry the risk.",
        "ghs": [
          "H317",
          "H351",
          "H372"
        ],
        "source": "uddeholm-sis",
        "where": "Classification of the major hazard substances, Nickel entry (the sheet is for Uddeholm alloys, not a 347 sheet)"
      },
      {
        "text": "The same sheet quotes the CLP rule for steels: more than 10 % nickel is classed STOT RE1, 1 to 10 % nickel is classed STOT RE2, and more than 1 % nickel is classed Carcinogen Category 2. A 347 specification of 9 to 13 % nickel straddles the 10 % limit, so the class depends on the actual heat.",
        "ghs": [],
        "source": "uddeholm-sis",
        "where": "Note under the Nickel entry"
      },
      {
        "text": "The sheet says alloys containing nickel or chromium may cause health hazards by inhalation of dusts and fumes produced by mechanical and thermal treatment such as grinding, polishing, welding or cutting, and that prolonged or repeated skin contact may cause dermatitis in nickel-sensitised persons.",
        "ghs": [],
        "source": "uddeholm-sis",
        "where": "Description of Hazards"
      }
    ],
    "failure_risks": [
      {
        "mode": "Intergranular attack from chromium carbide",
        "trigger": "Exposure in the chromium-carbide range of 427 to 816 °C, for example after welding, where the carbon is not tied up by niobium",
        "consequence": "Chromium carbide forms at grain boundaries and the metal loses intergranular corrosion resistance. Combmet states that the niobium addition is what prevents this.",
        "severity": "moderate",
        "source": "combmet347",
        "where": "Description paragraph of the Combmet datasheet"
      },
      {
        "mode": "Polythionic acid stress corrosion cracking",
        "trigger": "Polythionic acid formed in oil-refinery equipment",
        "consequence": "Rolled Alloys and Smith say 347 has good resistance to this cracking. The sources print no crack or failure data for the grade.",
        "severity": "moderate",
        "source": "rolled347",
        "where": "Opening paragraph and Applications list of the Rolled Alloys datasheet"
      },
      {
        "mode": "Loss of strength when hot",
        "trigger": "Service at 800 °F and above",
        "consequence": "Typical tensile strength falls from 93.3 ksi at 68 °F to 69.5 ksi at 800 °F, and typical 0.2 % yield falls from 36.5 ksi to 29.7 ksi over the same range (Rolled Alloys).",
        "severity": "low",
        "source": "rolled347",
        "where": "Typical Tensile and Impact Properties table, columns 68 and 800"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "The grade is chosen where welded parts cannot be annealed afterwards, since Rolled Alloys says it keeps good resistance to intergranular corrosion in the as-welded condition.",
        "source": "rolled347",
        "where": "Features list of the Rolled Alloys datasheet"
      },
      {
        "text": "Smith says Type 347 is essentially non-magnetic in the annealed condition and can only be hardened by cold working, so strength depends on the temper.",
        "source": "smith347",
        "where": "Description paragraph of the Smith datasheet"
      },
      {
        "text": "Specify the temper and product form: the minimum values of ASTM A240 apply to sheet, and the typical annealed values in the Combmet sheet were measured on the ATI basis.",
        "source": "combmet347",
        "where": "Typical Room Temperature Mechanical Properties table and its footnote"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "thermal-control",
      "device": "Aircraft exhaust stacks and furnace heating elements",
      "example": "UPMET lists aircraft exhaust stacks, aircraft collector rings, cabin heaters, boiler casings and furnace heating elements among industry applications for 347 sheet, coil and bar. The GE GT193 aircraft engine specification is also listed.",
      "source": "upmet347",
      "where": "Industry Applications list"
    },
    {
      "application": "structures",
      "device": "Hanger rods, fired heater tubes, thermowells and reactor components",
      "example": "Smith lists oil refineries, fired heater tubes, thermowells, fluid catalytic cracking units, hanger rods and reactor components as typical applications for the grade.",
      "source": "smith347",
      "where": "Typical Applications list"
    },
    {
      "application": "thermal-control",
      "device": "Recuperator tube sheets and fired heater tubes in refineries",
      "example": "Rolled Alloys lists recuperator tube sheets, shells and supports, fired heater tubes and distributor trays, with the note that 347 is especially suited where temperatures exceed 550 °F and sulfidation resistance is needed.",
      "source": "rolled347",
      "where": "Applications list of the Rolled Alloys datasheet"
    }
  ],
  "supply": [
    {
      "subject": "Nickel (world mine production, nickel content, 2025 estimate)",
      "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": "New Caledonia",
          "share_percent": 3.6,
          "year": 2025
        },
        {
          "country": "Canada",
          "share_percent": 3.6,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: nickel recovered from scrap accounted for about 60 % of U.S. apparent consumption in 2025; most secondary nickel went into new stainless steel and alloys.",
      "substitutes": [
        "USGS: low-nickel, duplex or ultrahigh-chromium stainless steels have been substituted for austenitic grades in construction; titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments."
      ],
      "source": "usgs-nickel-2026",
      "where": "World Mine Production and Reserves table, 2025e world total 3,900,000 t; shares calculated by Space Mushroom from the country values 2,600,000; 270,000; 200,000; 140,000; 140,000. Recycling; Substitutes; Domestic Production and Use (stainless and alloy steel more than 85 % of U.S. consumption)."
    },
    {
      "subject": "Chromium (world mine production, chromium content, 2025 estimate)",
      "producers": [
        {
          "country": "South Africa",
          "share_percent": 45.1,
          "year": 2025
        },
        {
          "country": "Turkey",
          "share_percent": 17.6,
          "year": 2025
        },
        {
          "country": "Kazakhstan",
          "share_percent": 13.7,
          "year": 2025
        },
        {
          "country": "India",
          "share_percent": 5.9,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: recycled chromium in stainless-steel scrap receipts accounted for 21 % of U.S. apparent consumption in 2025.",
      "substitutes": [
        "USGS: chromium has no substitute in stainless steel, the leading end use."
      ],
      "source": "usgs-chromium-2026",
      "where": "World Mine Production and Reserves table, 2025e world total 51,000 thousand t; shares calculated by Space Mushroom from the country values 23,000; 9,000; 7,000; 3,000. Recycling paragraph; Substitutes paragraph."
    },
    {
      "subject": "Niobium (columbium) (world mine production, niobium content, 2025 estimate)",
      "producers": [
        {
          "country": "Brazil",
          "share_percent": 92.9,
          "year": 2025
        },
        {
          "country": "Canada",
          "share_percent": 5.4,
          "year": 2025
        },
        {
          "country": "Congo (Kinshasa)",
          "share_percent": 0.9,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: scrap recovery of niobium was negligible; niobium was recycled mainly as part of niobium-bearing steels and superalloys.",
      "substitutes": [
        "USGS: ceramic matrix composites, molybdenum, tantalum and tungsten can replace niobium in high-temperature superalloy uses, with a performance loss or higher cost."
      ],
      "source": "usgs-niobium-2026",
      "where": "World Mine Production and Reserves table, 2025e world total 112,000 t; shares calculated by Space Mushroom from the country values 104,000; 6,000; 970. Brazil is also printed as approximately 93 % of global production in the Domestic Production and Use text. Recycling; Substitutes; Events, Trends, and Issues (steels about 77 % of U.S. consumption)."
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
      "type": "datasheet",
      "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
      "year": 2026
    },
    {
      "title": "Alloy 347 Stainless Steel Data Sheet, Combined Metals Company (rev 2024-01-16)",
      "type": "datasheet",
      "url": "https://www.combmet.com/wp-content/uploads/2024/01/Alloy-347-Stainless-Steel-Data-Sheet-2024-01-16.pdf",
      "year": 2024
    },
    {
      "title": "Stainless Steel S34700 Sheet, Aalco datasheet",
      "type": "datasheet",
      "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-S34700-Sheet_270.ashx"
    },
    {
      "title": "347 Stainless Technical Datasheet, Smiths Metal Centres (2023)",
      "type": "datasheet",
      "url": "https://www.smithmetal.com/pdf/stainless/347-stainless.pdf",
      "year": 2023
    },
    {
      "title": "Bulletin 147 Type 347/347H stainless steel data sheet, Rolled Alloys (rev 03/21)",
      "type": "datasheet",
      "url": "https://www.rolledalloys.ca/wp-content/uploads/347_stainless-steel-data-sheet-rolled-alloys.pdf",
      "year": 2021
    },
    {
      "title": "Alloy 347 UNS S34700 WNR 1.4550, Fine Tubes product page",
      "type": "report",
      "url": "https://www.finetubes.co.uk/products/materials/stainless-steel-tubes/alloy-347-uns-s34700-wnr-1-4550"
    },
    {
      "title": "X6CrNiNb18 10 austenitic stainless steel, Tachart material page",
      "type": "report",
      "url": "https://www.tachart.com/material/x6crninb18-10/"
    },
    {
      "title": "Stal nierdzewna 0H18N12Nb, 1.4550, X6CrNiNb18-10, AISI 347, AMS 5646 (Alfa-Tech datasheet)",
      "type": "datasheet",
      "url": "https://www.alfa-tech.com.pl/stal-nierdzewna-1-4550-1-4546-x6crninb1810-aisi-34-ams-5646-0h18n12nb/?pdf=6903"
    },
    {
      "title": "Alloys delivered from Uddeholms AB, material safety information sheet (release 2010-01-04, review 2018-09-10)",
      "type": "sds",
      "url": "https://www.uddeholm.com/app/uploads/sites/235/2024/05/Alloys-delivered-from-Uddeholms-AB.pdf"
    },
    {
      "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: Chromium",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Niobium (Columbium)",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-niobium.pdf",
      "year": 2026
    }
  ],
  "gaps": [
    "No Outokumpu, ATI or Sandvik datasheet for 347 could be opened; the Outokumpu search returned no 347 page, and the ATI page was not reached. The annealed typical values come from the Combmet sheet, which cites ATI.",
    "Hardness is not a canonical property name in spores/property-canon.yaml, so the benchmark is written as hardness; the three hardness rows use HB, HRB and HRBW as printed.",
    "The PubChem record for nickel was blocked by a reCAPTCHA check, so the nickel GHS classes come from the Uddeholm safety information sheet for steel articles, not from PubChem or a 347 sheet. No safety data sheet for the 347 base alloy was opened.",
    "The Uddeholm sheet is for Uddeholm alloys (release 2010, review 2018) and states the CLP steel rule in general terms; it is cited for the rule, not as a 347 classification.",
    "Composition conflicts between sources: nickel is 9 to 13 % in the ASTM A240 limits (Aalco, Rolled Alloys, Alfa-Tech) but 9 to 12 % in UPMET and Combmet; silicon is 0.75 % maximum (Aalco, UPMET) but 1.00 % nominal in Combmet; phosphorus is 0.04 % (Aalco) or 0.045 % (UPMET, Rolled Alloys). The recipe uses the Aalco ASTM A240 limits and states the conflicts.",
    "The Smith datasheet prints the density as 7.93 kg/m3 and the composition row for Nb plus Ta is garbled; neither is used.",
    "The UPMET table of thermal conductivity, specific heat, electrical resistivity and CTE carries no grade label, only the datasheet title; those rows are marked in their notes.",
    "No cryogenic, radiation, outgassing, cold-welding or atomic-oxygen data were found for 347 in this run.",
    "No critical-mineral list status for nickel, chromium or niobium was read from the official list; the USGS summaries name nickel in an executive-order context only, so critical_lists is left empty.",
    "The 800 °F typical tensile value is printed in ksi and converted on import; the printed 800 °F corresponds to about 427 °C.",
    "No process route (smelting, melting, refining) for 347 was read from a primary source, so the recipe has no process description.",
    "Elongation and hardness values were read from different product forms (sheet, plate, strip, annealed bar); each row states its form.",
    "Atomic weights were not read from a fetched page and are left out of the recipe parts.",
    "Trade names beyond the generic mill names Alloy 347 and Type 347 were not found in a fetched page; the GOST and Ukrainian 08Kh18N12B code printed on a distributor page was left out because the page's composition was unreliable."
  ],
  "story": {
    "why": "AISI 347 is a stainless steel that keeps its corrosion resistance after welding and heating. It has 17 to 19 % chromium and 9 to 13 % nickel, and niobium (columbium) ties up the carbon so chromium carbide does not form at the grain boundaries. The UPMET datasheet prints a density of 7.96 g/cm3 for grade 347 and a melting range of 1398 to 1446 °C. Smith prints a maximum use temperature in air of 800 °C.",
    "uses": [
      {
        "where": "Furnace and exhaust hardware",
        "line": "UPMET lists aircraft exhaust stacks, cabin heaters, furnace heating elements and boiler casings among its industry applications for 347 sheet, coil and bar."
      },
      {
        "where": "Refinery and reactor parts",
        "line": "Smith lists fired heater tubes, thermowells, hanger rods and reactor components. Rolled Alloys lists recuperator tube sheets, distributor trays and equipment around reactors."
      }
    ],
    "can_do": [
      {
        "label": "Carry heat in air",
        "line": "Smith prints a maximum use temperature in air of 800 °C. Rolled Alloys says the grade is useful to 1500 °F for oxidation.",
        "benchmark": "max_service_temp",
        "scope": "material",
        "value": "800 °C"
      },
      {
        "label": "Resist welding damage",
        "line": "Combmet says the niobium stabilisation resists intergranular corrosion after exposure in the chromium-carbide range from 800 to 1500 °F.",
        "scope": "material",
        "value": "427 to 816 °C"
      },
      {
        "label": "Stiffness",
        "line": "The modulus of elasticity at 20 °C is 193 GPa, from the Combmet datasheet.",
        "benchmark": "elastic_modulus",
        "scope": "material",
        "value": "193 GPa"
      },
      {
        "label": "Strength when annealed",
        "line": "Typical annealed tensile strength is 640 MPa and typical 0.2 % yield is 250 MPa (Combmet, based on ATI data). ASTM A240 minimums are 515 MPa and 205 MPa.",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material",
        "value": "640 MPa"
      }
    ],
    "compare": "Type 347 is the niobium-stabilised sibling of Type 321, which is stabilised with titanium. Rolled Alloys says 347 has slightly improved corrosion resistance over 321 in strongly oxidising environments, and that both offer good resistance to polythionic acid stress corrosion cracking. The sibling 321 profile is in this site as stainless-321.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Melting range",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Thermal conductivity",
        "benchmark": "thermal_conductivity",
        "scope": "material"
      }
    ],
    "handling": [
      "Specify the temper and product form, because the minimums of ASTM A240 apply to sheet and the typical annealed values are for annealed material.",
      "Weld in the as-welded condition where needed; the grade resists intergranular attack without re-annealing (Rolled Alloys).",
      "Control dust and fumes when grinding, polishing, welding or cutting, since the Uddeholm sheet names inhalation of nickel and chromium dust and fumes as the hazard."
    ],
    "good_for": [
      "Welded hot-service parts that cannot be annealed afterwards, rated to 800 °C in air (Smith).",
      "Refinery service where polythionic acid cracking is a concern (Rolled Alloys).",
      "Heating elements, exhaust stacks and furnace parts (UPMET application list)."
    ],
    "watch_out": [
      "Strength falls when hot: 93.3 ksi at 68 °F against 69.5 ksi at 800 °F (Rolled Alloys).",
      "Nickel content of 9 to 13 % puts the hazard class on the 10 % CLP line, so check the heat certificate (Uddeholm sheet).",
      "Cold work is the only way to harden it, so the temper sets the strength (Smith).",
      "No vacuum, radiation or atomic-oxygen data were found for this profile."
    ],
    "verdict": "AISI 347 is a welded, niobium-stabilised austenitic stainless steel with a printed maximum use temperature of 800 °C in air, 193 GPa modulus and typical annealed strength of 640 MPa. Its hot strength drops steeply above room temperature, its nickel content sets the hazard class of its dust and fumes, and this profile lacks space-environment numbers.",
    "recipe": {
      "line": "AISI 347 is an iron-based austenitic alloy. Composition in weight percent is the ASTM A240 limits printed in the Aalco datasheet, with the niobium row from UPMET; Combmet's nominal table prints silicon 1.00 % maximum and nickel 9 to 12 %, which differ. The process route (melting and casting) was not read from a primary source.",
      "parts": [
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "The matrix of the alloy; the other elements are dissolved in it."
        },
        {
          "name": "Chromium",
          "symbol": "Cr",
          "role": "Gives the stainless steel its corrosion and oxidation resistance (Aalco, UPMET, Combmet)."
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Keeps the structure austenitic and non-magnetic when annealed (Smith)."
        },
        {
          "name": "Niobium (columbium), with tantalum",
          "symbol": "Nb",
          "role": "The stabiliser that ties up carbon so that chromium carbide does not form at grain boundaries (Combmet, Rolled Alloys)."
        },
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Kept low; niobium binds the carbon that remains."
        },
        {
          "name": "Manganese",
          "symbol": "Mn",
          "role": "Printed in the ASTM A240 limits; the sources read give no function for it."
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Printed in the composition tables; the datasheets give no function."
        },
        {
          "name": "Phosphorus",
          "symbol": "P",
          "role": "An impurity limit in the ASTM A240 composition."
        },
        {
          "name": "Sulphur",
          "symbol": "S",
          "role": "An impurity limit in the ASTM A240 composition."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "Dust and fumes from working the steel carry the hazards, because the sources classify nickel, not the massive metal.",
        "points": [
          {
            "label": "Nickel in the alloy",
            "line": "Uddeholm's safety information sheet for steel articles classes nickel with H317, H351 and H372 (DANGER). It says massive steel needs no label, but dust and fumes from grinding, polishing, welding or cutting carry the risk."
          },
          {
            "label": "Nickel limit rule",
            "line": "The same sheet puts steels above 10 % nickel in STOT RE1 and steels above 1 % nickel in Carcinogen Category 2. The 347 range of 9 to 13 % nickel straddles the 10 % line, so the class depends on the actual heat."
          }
        ],
        "level": 1,
        "verdict": "Nickel classes apply to dust and fumes"
      },
      {
        "title": "If it fails",
        "lead": "These are failure routes printed in the sources. None is a measured space result.",
        "points": [
          {
            "label": "Intergranular attack",
            "line": "Combmet says the niobium addition resists intergranular corrosion after exposure at 427 to 816 °C, the range where chromium carbide forms in unstabilised grades."
          },
          {
            "label": "Polythionic acid",
            "line": "Rolled Alloys and Smith say 347 has good resistance to polythionic acid stress corrosion cracking, which arises in oil-refinery equipment."
          },
          {
            "label": "Hot strength",
            "line": "Rolled Alloys gives a typical tensile strength of 93.3 ksi at 68 °F and 69.5 ksi at 800 °F."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Welds that cannot be annealed",
            "line": "Rolled Alloys says the grade keeps good resistance to intergranular corrosion in the as-welded condition, which is why it is chosen for welded parts."
          },
          {
            "label": "Temper",
            "line": "Smith says the alloy is essentially non-magnetic when annealed and can only be hardened by cold working."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-25",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 21,
    "unreachable": 2,
    "caveats": 6,
    "note": "Values were read by an AI assistant on 2026-10-25 from the pages and PDFs named in each entry. Unreachable: PubChem (reCAPTCHA) and the Ulbrich 347 page (HTTP 403). Caveats: the datasheet values are nominal or typical values of several producers; the UPMET thermal, specific heat and resistivity tables carry no grade label; the hazard classes come from a general steel-article sheet for Uddeholm alloys; the nickel composition ranges differ between sources; the 800 °F tensile value is converted on import from ksi."
  },
  "sources": {
    "upmet347": {
      "title": "Datasheet for 347 Stainless Steel Sheet, Coil and Bar, AMS 5512, 5646 (United Performance Metals)",
      "id": "AMS 5512, AMS 5646, UNS S34700",
      "url": "https://www.upmet.com/sites/default/files/products/datasheet/347-datasheet.pdf",
      "year": 2026,
      "kind": "datasheet",
      "license": "Manufacturer datasheet, for information only (cited, not reproduced)"
    },
    "combmet347": {
      "title": "Alloy 347 Stainless Steel Data Sheet, Combined Metals Company (REV 2024 01 16)",
      "id": "UNS S34700, EN-DIN 1.4550; typical values based on ATI source, ASTM A240",
      "url": "https://www.combmet.com/wp-content/uploads/2024/01/Alloy-347-Stainless-Steel-Data-Sheet-2024-01-16.pdf",
      "year": 2024,
      "kind": "datasheet",
      "license": "Distributor datasheet, reference only (cited, not reproduced)"
    },
    "aalco347": {
      "title": "Stainless Steel S34700 Sheet, Aalco datasheet (ASTM A240 limits)",
      "id": "Spec: ASTM A240",
      "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-S34700-Sheet_270.ashx",
      "kind": "datasheet",
      "license": "Distributor datasheet (cited, not reproduced)"
    },
    "smith347": {
      "title": "347 Stainless Technical Datasheet, Smiths Metal Centres (2023)",
      "url": "https://www.smithmetal.com/pdf/stainless/347-stainless.pdf",
      "year": 2023,
      "kind": "datasheet",
      "license": "Distributor datasheet, approximate testing (cited, not reproduced)"
    },
    "rolled347": {
      "title": "Bulletin No. 147, 347/347H Data Sheet, Rolled Alloys (USe 03/21)",
      "id": "UNS S34700, S34709; AMS 5512; ASTM A240, A262; ASME SA-240",
      "url": "https://www.rolledalloys.ca/wp-content/uploads/347_stainless-steel-data-sheet-rolled-alloys.pdf",
      "year": 2021,
      "kind": "datasheet",
      "license": "Manufacturer datasheet (cited, not reproduced)"
    },
    "finetubes347": {
      "title": "Alloy 347 UNS S34700 WNR 1.4550, Fine Tubes product page",
      "id": "WNR 1.4550; ASTM A269, A213, A312; BS 2T66, 2T68, T72; SAE AMS 5571",
      "url": "https://www.finetubes.co.uk/products/materials/stainless-steel-tubes/alloy-347-uns-s34700-wnr-1-4550",
      "kind": "web",
      "license": "Supplier web page (cited, not reproduced)"
    },
    "tachart347": {
      "title": "X6CrNiNb18 10 austenitic stainless steel, Tachart material page",
      "id": "JIS SUS347; EN 1.4550; UNS S34700; alias Alloy 347",
      "url": "https://www.tachart.com/material/x6crninb18-10/",
      "kind": "web",
      "license": "Supplier web page (cited, not reproduced)"
    },
    "alfa347": {
      "title": "Stal nierdzewna 0H18N12Nb, 1.4550, 1.4546, X6CrNiNb18-10, AISI 347, AMS 5646 (Alfa-Tech)",
      "id": "X6CrNiNb18-10, 1.4550 EN 10088-2:2014, AISI 347, AMS 5646, TP347, S34700",
      "url": "https://www.alfa-tech.com.pl/stal-nierdzewna-1-4550-1-4546-x6crninb1810-aisi-34-ams-5646-0h18n12nb/?pdf=6903",
      "kind": "datasheet",
      "license": "Supplier datasheet (cited, not reproduced)"
    },
    "uddeholm-sis": {
      "title": "Alloys delivered from Uddeholms AB, material safety information sheet (release 2010-01-04, review 2018-09-10)",
      "url": "https://www.uddeholm.com/app/uploads/sites/235/2024/05/Alloys-delivered-from-Uddeholms-AB.pdf",
      "kind": "datasheet",
      "license": "Manufacturer safety information sheet (cited, not reproduced)"
    },
    "usgs-nickel-2026": {
      "title": "Mineral Commodity Summaries 2026, Nickel",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-chromium-2026": {
      "title": "Mineral Commodity Summaries 2026, Chromium",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-niobium-2026": {
      "title": "Mineral Commodity Summaries 2026, Niobium (Columbium)",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-niobium.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/stainless-347/"
}