{
  "spore": "profile",
  "id": "stainless-309",
  "spore_version": "0.2",
  "family": "stainless-austenitic",
  "name": "AISI 309 stainless steel",
  "abbreviation": "309",
  "role": "Chromium-nickel austenitic stainless steel for hot oxidising and sulphur-bearing furnace service",
  "category": "metals",
  "type": "steels-and-stainless",
  "summary": "AISI 309 (UNS S30900) is an austenitic stainless steel with 22.00 to 24.00 % chromium and 12.00 to 15.00 % nickel, built for heat. Its carbon limit is 0.20 % maximum, which is higher than the low-carbon 309S variant (0.08 % maximum). The Jacquet technical sheet prints a density of 8.03 g/cm3 and a modulus of 200 GPa, and a typical tensile strength of 621 MPa at room temperature that falls to 379 MPa at 1200 °F. The Rolled Alloys and NKS sheets print oxidation resistance to 1900 to 2000 °F. No space-environment data were found for this grade.\n",
  "best_for": "Hot furnace and heat-treatment parts that must resist oxidation to about 1900 to 2000 °F and keep a useful share of their room-temperature strength (Rolled Alloys, NKS, Jacquet)",
  "weakest_at": "Carburising atmospheres and hot strength: moderate resistance to carbon absorption (Rolled Alloys), and typical tensile strength falls from 90.0 ksi at 77 °F to 55.0 ksi at 1200 °F (Jacquet)",
  "identity": {
    "formula": "Fe-based austenitic alloy: Fe balance, Cr 22.00 to 24.00 %, Ni 12.00 to 15.00 %, C 0.20 % maximum, Mn 2.00 % maximum, Si 0.75 % maximum, P 0.045 % maximum, S 0.030 % maximum (ASTM A167 and A240 limits)",
    "designations": [
      {
        "system": "UNS",
        "code": "S30900",
        "source": "jacquet309",
        "where": "Chemical Composition table, column 309 (UNS S30900); Relevant Standards table, row 309"
      },
      {
        "system": "AISI",
        "code": "309",
        "source": "jacquet309",
        "where": "Relevant Standards table, row 309, AISI 309"
      },
      {
        "system": "SAE",
        "code": "30309",
        "source": "jacquet309",
        "where": "Relevant Standards table, row 309, SAE 30309"
      },
      {
        "system": "ASTM",
        "code": "A167",
        "note": "sheet and strip, Type 309",
        "source": "nks309",
        "where": "Specifications line, ASTM A167 (309)"
      },
      {
        "system": "Trade name",
        "code": "Type 309",
        "source": "nks309",
        "where": "Title line and description paragraph, Types 309 Stainless Steel"
      }
    ],
    "source": "jacquet309",
    "where": "Chemical Composition table, column 309 (UNS S30900); the sheet states that its limits are from ASTM A167 and A240. The same limits are printed in the NKS datasheet, Chemical Composition table, Type 309 column."
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "thermal-control",
      "structures"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, 309",
      "value": 8.03,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "temperature": "68 °F (20 °C)",
        "unit_in_source": "0.29 lbm/in3",
        "basis": "representative for average composition in the annealed condition"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, row Density, column 309",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting range, NKS datasheet",
      "value": 2550,
      "value_high": 2650,
      "bound": "range",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "grade": "309 and 309S (one range printed for both)",
        "unit_in_source": "2550 - 2650 °F"
      },
      "method": "Melting range printed in a manufacturer datasheet",
      "status": "ground",
      "note": "The Rolled Alloys sheet prints a different range (2500 to 2590 °F); both are kept.",
      "source": "nks309",
      "where": "Physical Properties section, Melting Point Range (oF)",
      "source_detail": {
        "title": "309 & 309S Stainless Steel (NKS datasheet)",
        "id": "ASTM A167 (309), ASTM A240 (309S)",
        "url": "https://nks.com/wp-content/uploads/309-309S-Stainless-Steel.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting range, Rolled Alloys sheet",
      "value": 2500,
      "value_high": 2590,
      "bound": "range",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "grade": 309,
        "unit_in_source": "2500 - 2590 °F"
      },
      "method": "Melting range printed in a manufacturer datasheet",
      "status": "ground",
      "note": "The NKS datasheet prints a different range (2550 to 2650 °F); both are kept.",
      "source": "rolled309",
      "where": "Physical Properties block, Melting Range: 2500 - 2590°F",
      "source_detail": {
        "title": "Bulletin No. 109, 309 Stainless Steel data sheet (Rolled Alloys)",
        "id": "UNS S30908, S30909; W. Nr. 1.4833; AMS 5523",
        "url": "https://www.rolledalloys.com/wp-content/uploads/309_stainless-steel-data-sheet-rolled-alloys.pdf",
        "year": 2012,
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity in tension, annealed",
      "value": 200,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "state": "annealed",
        "temperature": "not stated",
        "note": "The source prints one value that it says is common to both 309 and 310",
        "unit_in_source": "29 x 10^6 psi"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, row Modulus of Elasticity (annealed), in tension (E), GPa",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, 20 to 100 °C",
      "value": 15.6,
      "bound": "exact",
      "unit": "W/m·K",
      "scope": "material",
      "conditions": {
        "temperature_range": "68 to 212 °F (20 to 100 °C)",
        "unit_in_source": "9.0 Btu/hr·ft·°F"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, Thermal Conductivity, row 68 to 212 °F, column 309, W/m·K",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, 20 to 500 °C",
      "value": 18.7,
      "bound": "exact",
      "unit": "W/m·K",
      "scope": "material",
      "conditions": {
        "temperature_range": "68 to 932 °F (20 to 500 °C)",
        "unit_in_source": "10.8 Btu/hr·ft·°F"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, Thermal Conductivity, row 68 to 932 °F, column 309, W/m·K",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat capacity, 0 to 100 °C",
      "value": 502,
      "bound": "exact",
      "unit": "J/kg·K",
      "scope": "material",
      "conditions": {
        "temperature_range": "32 to 212 °F (0 to 100 °C)",
        "unit_in_source": "0.12 Btu/lbm·°F"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, Specific Heat, row 32 to 212 °F, column 309, J/kg·K",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity at 20 °C",
      "value": 78,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "temperature": "68 °F (20 °C)",
        "unit_in_source": "30.7 µΩ·in"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, Electrical Resistivity, row 68 °F (20 °C), column 309, µΩ·cm",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity at 648 °C",
      "value": 114.8,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "temperature": "1200 °F (648 °C)",
        "unit_in_source": "45.1 µΩ·in"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, Electrical Resistivity, row 1200 °F (648 °C), column 309, µΩ·cm",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of linear thermal expansion, 20 to 100 °C",
      "value": 15.6,
      "bound": "exact",
      "unit": "µm/(m·K)",
      "scope": "material",
      "conditions": {
        "temperature_range": "68 to 212 °F (20 to 100 °C)",
        "unit_in_source": "8.7 µin/(in·°F)"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, Coefficient of Thermal Expansion, row 68 to 212 °F (20 to 100 °C), column 309, (µm/m)·K",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of linear thermal expansion, 20 to 500 °C",
      "value": 17.6,
      "bound": "exact",
      "unit": "µm/(m·K)",
      "scope": "material",
      "conditions": {
        "temperature_range": "68 to 932 °F (20 to 500 °C)",
        "unit_in_source": "9.8 µin/(in·°F)"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, Coefficient of Thermal Expansion, row 68 to 932 °F (20 to 500 °C), column 309, (µm/m)·K",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of linear thermal expansion, 20 to 1000 °C",
      "value": 19.4,
      "bound": "exact",
      "unit": "µm/(m·K)",
      "scope": "material",
      "conditions": {
        "temperature_range": "68 to 1832 °F (20 to 1000 °C)",
        "unit_in_source": "10.8 µin/(in·°F)"
      },
      "method": "Value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Physical Properties table, Coefficient of Thermal Expansion, row 68 to 1832 °F (20 to 1000 °C), column 309, (µm/m)·K",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength 0.2 % offset, typical, 25 °C",
      "value": 290,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "77 °F (25 °C)",
        "basis": "typical short-term values, ASTM E8, average of two to ten samples",
        "unit_in_source": "42.0 ksi"
      },
      "method": "Typical value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Typical Short-Term Mechanical Properties table, grade 309, row 77 (25), column Yield Strength MPa",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength 0.2 % offset, typical, 427 °C",
      "value": 207,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "800 °F (427 °C)",
        "basis": "typical short-term values, ASTM E8, average of two to ten samples",
        "unit_in_source": "30.0 ksi"
      },
      "method": "Typical value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Typical Short-Term Mechanical Properties table, grade 309, row 800 (427), column Yield Strength MPa",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength 0.2 % offset, typical, 649 °C",
      "value": 152,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "1200 °F (649 °C)",
        "basis": "typical short-term values, ASTM E8, average of two to ten samples",
        "unit_in_source": "22.0 ksi"
      },
      "method": "Typical value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Typical Short-Term Mechanical Properties table, grade 309, row 1200 (649), column Yield Strength MPa",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, typical, 25 °C",
      "value": 621,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "77 °F (25 °C)",
        "basis": "typical short-term values, ASTM E8, average of two to ten samples",
        "unit_in_source": "90.0 ksi"
      },
      "method": "Typical value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Typical Short-Term Mechanical Properties table, grade 309, row 77 (25), column Tensile Strength MPa",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, typical, 427 °C",
      "value": 497,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "800 °F (427 °C)",
        "basis": "typical short-term values, ASTM E8, average of two to ten samples",
        "unit_in_source": "72.0 ksi"
      },
      "method": "Typical value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Typical Short-Term Mechanical Properties table, grade 309, row 800 (427), column Tensile Strength MPa",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, typical, 649 °C",
      "value": 379,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "1200 °F (649 °C)",
        "basis": "typical short-term values, ASTM E8, average of two to ten samples",
        "unit_in_source": "55.0 ksi"
      },
      "method": "Typical value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Typical Short-Term Mechanical Properties table, grade 309, row 1200 (649), column Tensile Strength MPa",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, typical, 25 °C",
      "value": 49,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temperature": "77 °F (25 °C)",
        "gauge_length": "2 in (50.8 mm)",
        "basis": "typical short-term values, ASTM E8"
      },
      "method": "Typical value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Typical Short-Term Mechanical Properties table, grade 309, row 77 (25), column Elongation %",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, typical, 427 °C",
      "value": 40,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temperature": "800 °F (427 °C)",
        "gauge_length": "2 in (50.8 mm)",
        "basis": "typical short-term values, ASTM E8"
      },
      "method": "Typical value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Typical Short-Term Mechanical Properties table, grade 309, row 800 (427), column Elongation %",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, typical, 649 °C",
      "value": 35,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temperature": "1200 °F (649 °C)",
        "gauge_length": "2 in (50.8 mm)",
        "basis": "typical short-term values, ASTM E8"
      },
      "method": "Typical value printed in a manufacturer technical sheet",
      "status": "ground",
      "source": "jacquet309",
      "where": "Typical Short-Term Mechanical Properties table, grade 309, row 1200 (649), column Elongation %",
      "source_detail": {
        "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
        "id": "UNS S30900, S30908, S31000, S31008",
        "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "Manufacturer technical sheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength 0.2 % offset, minimum, ASTM A167",
      "value": 30,
      "bound": "lower",
      "unit": "ksi",
      "scope": "material",
      "conditions": {
        "spec": "ASTM A167 (309)",
        "form": "sheet and strip",
        "measure": "0.2 % offset, minimum"
      },
      "method": "Minimum value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "nks309",
      "where": "Mechanical Properties table, row 309, column Yield Strength 0.2% offset (KSI), value 30 min.",
      "source_detail": {
        "title": "309 & 309S Stainless Steel (NKS datasheet)",
        "id": "ASTM A167 (309), ASTM A240 (309S)",
        "url": "https://nks.com/wp-content/uploads/309-309S-Stainless-Steel.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, minimum, ASTM A167",
      "value": 75,
      "bound": "lower",
      "unit": "ksi",
      "scope": "material",
      "conditions": {
        "spec": "ASTM A167 (309)",
        "form": "sheet and strip"
      },
      "method": "Minimum value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "nks309",
      "where": "Mechanical Properties table, row 309, column Tensile Strength (KSI), value 75 min.",
      "source_detail": {
        "title": "309 & 309S Stainless Steel (NKS datasheet)",
        "id": "ASTM A167 (309), ASTM A240 (309S)",
        "url": "https://nks.com/wp-content/uploads/309-309S-Stainless-Steel.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation, minimum, ASTM A167",
      "value": 40,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "spec": "ASTM A167 (309)",
        "form": "sheet and strip",
        "gauge_length": "2 in"
      },
      "method": "Minimum value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "nks309",
      "where": "Mechanical Properties table, row 309, column % Elongation (2 in Gauge Length), value 40.0 min.",
      "source_detail": {
        "title": "309 & 309S Stainless Steel (NKS datasheet)",
        "id": "ASTM A167 (309), ASTM A240 (309S)",
        "url": "https://nks.com/wp-content/uploads/309-309S-Stainless-Steel.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Oxidation resistance, continuous service",
      "value": 2000,
      "bound": "exact",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "environment": "air",
        "basis": "oxidation rating for continuous service, not a mechanical limit"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "nks309",
      "where": "Physical Properties section, Oxidation Resistance - Continuous Service (oF)",
      "source_detail": {
        "title": "309 & 309S Stainless Steel (NKS datasheet)",
        "id": "ASTM A167 (309), ASTM A240 (309S)",
        "url": "https://nks.com/wp-content/uploads/309-309S-Stainless-Steel.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Oxidation resistance, intermittent service",
      "value": 1800,
      "bound": "exact",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "environment": "air",
        "basis": "oxidation rating for intermittent service, not a mechanical limit"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "nks309",
      "where": "Physical Properties section, Oxidation Resistance - Intermittent Service (oF)",
      "source_detail": {
        "title": "309 & 309S Stainless Steel (NKS datasheet)",
        "id": "ASTM A167 (309), ASTM A240 (309S)",
        "url": "https://nks.com/wp-content/uploads/309-309S-Stainless-Steel.pdf",
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Oxidation resistance, constant temperature",
      "value": 1900,
      "bound": "exact",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "environment": "air",
        "basis": "oxidation rating under constant temperature; about 1850 °F with frequent thermal cycling (same sheet)"
      },
      "method": "Value printed in a manufacturer datasheet",
      "status": "ground",
      "source": "rolled309",
      "where": "Opening paragraph, 309 is an austenitic heat resistant alloy with oxidation resistance to 1900°F under constant temperature conditions",
      "source_detail": {
        "title": "Bulletin No. 109, 309 Stainless Steel data sheet (Rolled Alloys)",
        "id": "UNS S30908, S30909; W. Nr. 1.4833; AMS 5523",
        "url": "https://www.rolledalloys.com/wp-content/uploads/309_stainless-steel-data-sheet-rolled-alloys.pdf",
        "year": 2012,
        "kind": "datasheet",
        "license": "Manufacturer datasheet (cited, not reproduced)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Aqueous and nitric-acid service at room temperature",
      "headline": "Both NKS and Jacquet describe excellent general corrosion resistance; the grade is more resistant to marine air than 304.",
      "effect": "NKS says 309 provides excellent general corrosion resistance, is more resistant to marine atmospheres than Type 304, and is useful for handling nitric acid, nitric-sulfuric mixtures, and acetic, citric and lactic acids. Jacquet says the grade is resistant to aqueous corrosion because of its high chromium and nickel contents. Neither sheet prints a corrosion rate for 309.",
      "rating": "low",
      "conditions": {
        "basis": "datasheet statements; no corrosion rate or test duration printed for 309"
      },
      "source": "nks309",
      "where": "Corrosion section of the NKS datasheet; Jacquet, Aqueous Corrosion Resistance, opening paragraph"
    },
    {
      "environment": "High-temperature air oxidation",
      "headline": "Chromium-rich scale protects the grade in air up to about 1900 to 2000 °F.",
      "effect": "Rolled Alloys and NKS print oxidation ratings of 1900 °F (constant) and 2000 °F (continuous) in air. Jacquet says scale volatilisation becomes a significant problem above about 2000 °F and is worse in rapidly flowing gases, and that oxide scale spallation is the most common oxidation problem in stainless steels.",
      "rating": "low",
      "conditions": {
        "basis": "datasheet ratings and general oxidation discussion; no weight-gain or spalling data for 309 printed"
      },
      "source": "rolled309",
      "where": "Opening paragraph of the Rolled Alloys sheet; Jacquet, Elevated Temperature Oxidation Resistance"
    },
    {
      "environment": "Sulphur-bearing hot gases",
      "headline": "Good resistance to high-temperature sulphur atmospheres, with nickel content below the level that favours sulphidation.",
      "effect": "Rolled Alloys says the high chromium and relatively low nickel content of 309 give good resistance to high-temperature sulphur-bearing atmospheres. Jacquet says sulphidation is enhanced in alloys with about 25 % or more nickel, which is above the 309 range of 12 to 15 %.",
      "rating": "low",
      "conditions": {
        "basis": "datasheet statements; no sulphidation rate printed for 309"
      },
      "source": "rolled309",
      "where": "Opening paragraph of the Rolled Alloys sheet; Jacquet, Elevated Temperature Oxidation Resistance, sulfidation paragraph"
    },
    {
      "environment": "Carburising and metal-dusting atmospheres",
      "headline": "Moderate resistance to carbon absorption; not recommended for highly carburising atmospheres.",
      "effect": "Rolled Alloys says 309 has only moderate resistance to carbon absorption and is not suggested for highly carburising atmospheres. Jacquet says carburisation generally occurs above 800 °C (1470 °F) and metal dusting at 350 to 900 °C (660 to 1650 °F), and that higher nickel and silicon are somewhat effective in reducing carburisation susceptibility.",
      "rating": "moderate",
      "conditions": {
        "basis": "datasheet statements; no carburisation depth or weight-gain test printed for 309"
      },
      "source": "rolled309",
      "where": "Opening paragraph of the Rolled Alloys sheet; Jacquet, Carburization paragraphs"
    }
  ],
  "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 sheet says massive steel needs 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 309 sheet)"
      },
      {
        "text": "The same sheet quotes the CLP rule for steels: more than 10 % nickel should be classed STOT RE1, 1 to 10 % nickel STOT RE 2, and more than 1 % nickel Carcinogen Category 2. The 309 range of 12.00 to 15.00 % nickel is above the 10 % line and above the 1 % line, so the rule would apply to the grade; the sheet gives it as a general rule, not as a classification for 309.",
        "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": "Sigma phase embrittlement",
        "trigger": "Prolonged exposure in the 1100 to 1600 °F range",
        "consequence": "Rolled Alloys says sigma forms and lowers room-temperature ductility and impact resistance, so heavy impact at room temperature should be avoided after such exposure.",
        "severity": "moderate",
        "source": "rolled309",
        "where": "Opening paragraph of the Rolled Alloys sheet"
      },
      {
        "mode": "Carburisation and metal dusting",
        "trigger": "Service above about 800 °C (1470 °F) in carbon-bearing atmospheres; metal dusting at 350 to 900 °C",
        "consequence": "Internal carbides form, changing mechanical and physical properties; metal dusting can cause deep craters through the metal (Jacquet). Rolled Alloys says 309 is not suggested for highly carburising atmospheres.",
        "severity": "moderate",
        "source": "jacquet309",
        "where": "Carburization paragraphs of the Jacquet sheet; Rolled Alloys opening paragraph"
      },
      {
        "mode": "Loss of strength when hot",
        "trigger": "Service at 1200 °F",
        "consequence": "Typical tensile strength falls from 90.0 ksi at 77 °F to 55.0 ksi at 1200 °F, and typical 0.2 % yield strength from 42.0 ksi to 22.0 ksi (Jacquet).",
        "severity": "low",
        "source": "jacquet309",
        "where": "Typical Short-Term Mechanical Properties table, grade 309, rows 77 and 1200"
      },
      {
        "mode": "Hot cracking in welds",
        "trigger": "Restrained or wide joints welded with a low-ferrite filler metal",
        "consequence": "Jacquet says the high thermal expansion, low thermal conductivity and low ferrite in the weld metal can lead to hot cracking; a filler with lower alloy content, such as ER308, raises ferrite and reduces the risk, but dilutes the weld corrosion and heat resistance.",
        "severity": "moderate",
        "source": "jacquet309",
        "where": "Welding paragraph of the Jacquet sheet"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Anneal and water quench or rapidly air cool. NKS prints an anneal at 1900 to 2050 °F (1038 to 1121 °C); Jacquet prints a hold at 2050 to 2150 °F (1120 to 1175 °C) for about 30 minutes per inch of section. The two ranges differ, so follow the producer's heat-treatment instruction.",
        "source": "nks309",
        "where": "Processing section of the NKS datasheet; Jacquet, Heat Treatment / Annealing paragraph"
      },
      {
        "text": "Rolled Alloys recommends welding with AWS E309-16 covered electrodes or ER309 bare wire. Jacquet says the S grades are low in carbon, that ER309L can be used where low carbon is needed, and that heat tint must be removed to restore corrosion resistance near the weld.",
        "source": "rolled309",
        "where": "Opening paragraph and Welding paragraph of the Rolled Alloys sheet; Jacquet, Welding paragraphs"
      },
      {
        "text": "NKS says 309 is not hardenable by heat treatment, is essentially nonmagnetic as annealed, becomes lightly magnetic when cold worked, and forms readily; in-process annealing is usually needed to reduce hardness and restore ductility.",
        "source": "nks309",
        "where": "Description, Processing and Forming sections of the NKS datasheet"
      }
    ],
    "mitigations": [
      {
        "text": "Jacquet says oxygen normally prevents carbon ingress by forming a protective external scale, so carburisation is most likely where the gas is oxygen-poor.",
        "source": "jacquet309",
        "where": "Carburization paragraph of the Jacquet sheet"
      }
    ]
  },
  "uses": [
    {
      "application": "thermal-control",
      "device": "Furnace parts, heating elements and heat exchangers",
      "example": "NKS lists furnace parts, heating elements, aircraft and jet engine parts, heat exchangers, kiln liners and boiler baffles among the typical applications of 309 and 309S. The NKS page covers both grades.",
      "source": "nks309",
      "where": "Typical Applications section"
    },
    {
      "application": "thermal-control",
      "device": "Heat-treatment furnace parts, retorts and radiant tubes",
      "example": "Jacquet lists conveyor belts, rollers, burner parts, refractory supports, retorts, oven linings, fans and tube hangers for heat-treatment furnaces, and baskets and trays for small parts.",
      "source": "jacquet309",
      "where": "Applications paragraph of the Jacquet sheet"
    },
    {
      "application": "structures",
      "device": "Power boiler tube hangers and anchor bolts",
      "example": "Rolled Alloys lists power boiler tube hangers, anchor bolts, thermowells and glass forming equipment among its 309 applications.",
      "source": "rolled309",
      "where": "Applications list of the Rolled Alloys sheet"
    }
  ],
  "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 approximately 60 % of apparent consumption in 2025; most recycled nickel went into new alloys and stainless steel.",
      "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."
    },
    {
      "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, contained in stainless-steel scrap receipts, accounted for 21 % of apparent consumption in 2025.",
      "substitutes": [
        "USGS: chromium has no substitute in stainless steel, the leading end use, or in superalloys."
      ],
      "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."
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
      "type": "datasheet",
      "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
      "year": 2025
    },
    {
      "title": "309 & 309S Stainless Steel data sheet (NKS, 800-722-5029)",
      "type": "datasheet",
      "url": "https://nks.com/wp-content/uploads/309-309S-Stainless-Steel.pdf"
    },
    {
      "title": "Bulletin No. 109, 309 Stainless Steel data sheet (Rolled Alloys, rev 07/12)",
      "type": "datasheet",
      "url": "https://www.rolledalloys.com/wp-content/uploads/309_stainless-steel-data-sheet-rolled-alloys.pdf",
      "year": 2012
    },
    {
      "title": "UNS S30900 Stainless steels (TotalMateria)",
      "type": "database",
      "url": "https://www.totalmateria.com/en-us/material/1241521"
    },
    {
      "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",
      "year": 2018
    },
    {
      "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
    }
  ],
  "gaps": [
    "No hardness value for AISI 309 was read in a fetched source; the sheets give only 309S or unlabelled values, so no hardness property is entered.",
    "No EN, JIS or AMS designation was printed for AISI 309 by a source read in this run. EN 1.4833 and JIS SUS 309 belong to the 309S row of the Outokumpu table, and EN 1.4828 is the silicon-enriched 309Si grade, so they are left out.",
    "No vacuum, radiation, outgassing, atomic-oxygen, cryogenic or flight data were found for 309 in this run.",
    "The two sheets give different melting ranges (NKS 2550 to 2650 °F; Rolled Alloys 2500 to 2590 °F) and different annealing ranges (NKS 1900 to 2050 °F; Jacquet 2050 to 2150 °F). Both are kept as printed; no value was chosen.",
    "The modulus of 200 GPa is one value the Jacquet sheet says is common to both 309 and 310; it is not a grade-specific measurement.",
    "Nickel for UNS S30900 was not visible on the TotalMateria page (behind a free registration); the nickel range comes from the Jacquet and NKS sheets, which agree.",
    "No process route (melting, refining) for 309 was read from a primary source, so the recipe gives no process description.",
    "Atomic weights were not read from a fetched page and are left out of the recipe parts.",
    "Official critical-mineral list status for nickel and chromium was not read, so critical_lists is left empty.",
    "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 309 classification. No safety data sheet for a 309 base alloy was opened, and PubChem was not read for nickel.",
    "Aperam and ICAST sheets that describe 309S were found but not used, because 309S is a separate grade and their values are for 309S.",
    "Seven sources were reached, below the eight the lithium standard asks for. A search for Smiths Metal Centres, Combined Metals and Aalco 309 datasheets found no such page."
  ],
  "story": {
    "why": "AISI 309 is a chromium-nickel austenitic stainless steel built for heat. It carries 22 to 24 % chromium and 12 to 15 % nickel, which gives it oxidation resistance to about 1900 to 2000 °F in air and a good share of its strength at elevated temperature. Its carbon limit of 0.20 % is higher than the 309S variant, which is why 309S is the more common weldable choice. The Jacquet sheet prints a density of 8.03 g/cm3 and a modulus of 200 GPa for the family.",
    "uses": [
      {
        "where": "Furnace parts and heating elements",
        "line": "NKS lists furnace parts, heating elements, aircraft and jet engine parts, heat exchangers and kiln liners. Jacquet lists conveyor belts, rollers, burner parts, retorts and radiant parts for heat-treatment furnaces."
      },
      {
        "where": "Boiler and furnace supports",
        "line": "Rolled Alloys lists power boiler tube hangers, anchor bolts, thermowells and glass forming equipment among its 309 applications."
      }
    ],
    "can_do": [
      {
        "label": "Carry heat in air",
        "line": "NKS prints an oxidation rating of 2000 °F for continuous service and 1800 °F for intermittent service. Rolled Alloys prints 1900 °F for constant temperature.",
        "benchmark": "max_service_temp",
        "scope": "material",
        "value": "2000 °F"
      },
      {
        "label": "Strength when hot",
        "line": "Jacquet gives a typical tensile strength of 55.0 ksi at 1200 °F (379 MPa), down from 90.0 ksi at 77 °F.",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material",
        "value": "55 ksi at 1200 °F"
      },
      {
        "label": "Stiffness",
        "line": "The Jacquet sheet prints a modulus of elasticity of 200 GPa for annealed material, a value it says is common to 309 and 310.",
        "benchmark": "elastic_modulus",
        "scope": "material",
        "value": "200 GPa"
      },
      {
        "label": "Strength at room temperature",
        "line": "Jacquet gives a typical 0.2 % yield strength of 290 MPa (42.0 ksi) at 77 °F. The NKS minimum for ASTM A167 is 30 ksi.",
        "benchmark": "yield_strength",
        "scope": "material",
        "value": "290 MPa yield"
      }
    ],
    "compare": "309 sits in the same chromium-nickel family as 310, which carries more chromium and nickel than 309 (Jacquet). The sibling 310 profile is in this site as stainless-310. Jacquet says 310 has higher oxidation resistance and retains more room-temperature strength than the common austenitic alloys such as Type 304. Rolled Alloys says 309 is oxidation resistant to 1900 °F and has moderate strength at high temperature.",
    "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 grade (309 or 309S) and the product form, because the carbon limit and the minimum values differ between them.",
      "Anneal to restore ductility after heavy forming, and pick the annealing range that the producer prints for the heat.",
      "Weld with an AWS E309-16 electrode or ER309 wire (Rolled Alloys); remove heat tint after welding (Jacquet).",
      "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": [
      "Hot furnace and heat-treatment parts in air, rated to about 1900 to 2000 °F (Rolled Alloys, NKS).",
      "Sulphur-bearing hot gases, where the chromium-rich, low-nickel composition gives good resistance (Rolled Alloys).",
      "Heating elements, furnace fans and radiant tubes (NKS, Jacquet)."
    ],
    "watch_out": [
      "Carburising atmospheres: moderate resistance to carbon absorption, and not suggested for highly carburising service (Rolled Alloys).",
      "Prolonged exposure at 1100 to 1600 °F forms sigma, which lowers room-temperature ductility and impact resistance (Rolled Alloys).",
      "Strength falls when hot: 90.0 ksi at 77 °F against 55.0 ksi at 1200 °F (Jacquet).",
      "Nickel content of 12 to 15 % puts the hazard class above the 10 % CLP line, so check the heat certificate and treat dust as a hazard (Uddeholm sheet).",
      "No space-environment data (vacuum, radiation, atomic oxygen) were found for this profile."
    ],
    "verdict": "AISI 309 is an austenitic heat-resistant stainless steel rated to about 1900 to 2000 °F in air, with a modulus of 200 GPa and typical strength of 621 MPa at room temperature. Its strength falls steeply at high temperature, carburising atmospheres are a weak point, and the grade has no space-environment data in this profile.",
    "recipe": {
      "line": "AISI 309 is an iron-based austenitic alloy. Composition in weight percent is the ASTM A167 and A240 limits printed in the Jacquet sheet and the NKS datasheet; the TotalMateria UNS S30900 page prints the same carbon, manganese and chromium limits. The process route (melting and refining) 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 oxidation and corrosion resistance; the high chromium content is the main reason for the oxidation rating (Jacquet, Rolled Alloys)."
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Keeps the structure austenitic and non-magnetic when annealed (NKS); the 12 to 15 % range is also the source of the hazard class above the 10 % line (Uddeholm)."
        },
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Kept at a low level; the 309S variant limits it to 0.08 % maximum to reduce carbide precipitation (NKS)."
        },
        {
          "name": "Manganese",
          "symbol": "Mn",
          "role": "Printed in the ASTM A167 and A240 limits; the sheets give no function for it."
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Printed in the ASTM A167 and A240 limits; the sheets give no function for it."
        },
        {
          "name": "Phosphorus",
          "symbol": "P",
          "role": "An impurity limit in the ASTM A167 and A240 composition."
        },
        {
          "name": "Sulphur",
          "symbol": "S",
          "role": "An impurity limit in the ASTM A167 and 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 309 range of 12 to 15 % nickel sits above both lines, so the rule would apply to the grade."
          }
        ],
        "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": "Sigma phase",
            "line": "Rolled Alloys says prolonged exposure at 1100 to 1600 °F forms sigma, which lowers room-temperature ductility and impact resistance."
          },
          {
            "label": "Carburisation",
            "line": "Rolled Alloys says the grade has only moderate resistance to carbon absorption. Jacquet says carburisation occurs above 800 °C and metal dusting at 350 to 900 °C."
          },
          {
            "label": "Hot strength",
            "line": "Jacquet gives a typical tensile strength of 90.0 ksi at 77 °F and 55.0 ksi at 1200 °F."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Annealing",
            "line": "NKS prints an anneal at 1900 to 2050 °F and a water quench or rapid air cool. Jacquet prints a hold at 2050 to 2150 °F for about 30 minutes per inch. The two ranges differ."
          },
          {
            "label": "Welding",
            "line": "Rolled Alloys recommends AWS E309-16 electrodes or ER309 wire. Jacquet warns that the joint can hot-crack when it is restrained or wide."
          },
          {
            "label": "Magnetism",
            "line": "NKS says the grade is essentially nonmagnetic when annealed and becomes lightly magnetic when cold worked."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 27,
    "unreachable": 1,
    "caveats": 4,
    "note": "Values were read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry. Unreachable: Rolled Alloys HTML data-sheet pages (HTTP 404), Outokumpu grade page (HTTP 404), and the Aalco or Smiths 309 pages (not found by search). Caveats: the Jacquet modulus is common to 309 and 310; the NKS and Rolled Alloys melting and annealing ranges differ; the hazard classes come from a general steel-article sheet for Uddeholm alloys; the nickel composition is from two sheets, not from a 309-specific SDS."
  },
  "sources": {
    "jacquet309": {
      "title": "Technical Sheet 309/309S, 310/310S Stainless Steel: Austenitic (Jacquet)",
      "id": "UNS S30900, S30908, S31000, S31008",
      "url": "https://usa.myjacquet.com/wp-content/uploads/sites/55/2025/08/Technical_Sheet_309_310.pdf",
      "year": 2025,
      "kind": "datasheet",
      "license": "Manufacturer technical sheet (cited, not reproduced)"
    },
    "nks309": {
      "title": "309 & 309S Stainless Steel (NKS datasheet)",
      "id": "ASTM A167 (309), ASTM A240 (309S)",
      "url": "https://nks.com/wp-content/uploads/309-309S-Stainless-Steel.pdf",
      "kind": "datasheet",
      "license": "Manufacturer datasheet (cited, not reproduced)"
    },
    "rolled309": {
      "title": "Bulletin No. 109, 309 Stainless Steel data sheet (Rolled Alloys)",
      "id": "UNS S30908, S30909; W. Nr. 1.4833; AMS 5523",
      "url": "https://www.rolledalloys.com/wp-content/uploads/309_stainless-steel-data-sheet-rolled-alloys.pdf",
      "year": 2012,
      "kind": "datasheet",
      "license": "Manufacturer datasheet (cited, not reproduced)"
    },
    "totalmateria309": {
      "title": "UNS S30900 Stainless steels (TotalMateria)",
      "id": "UNS S30900",
      "url": "https://www.totalmateria.com/en-us/material/1241521",
      "kind": "database",
      "license": "Database page, reference only (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",
      "year": 2018,
      "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)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/stainless-309/"
}