{
  "spore": "profile",
  "id": "stainless-303",
  "spore_version": "0.2",
  "family": "stainless-austenitic",
  "name": "Stainless steel 303",
  "abbreviation": "303 (UNS S30300)",
  "role": "free-machining structural alloy",
  "category": "metals",
  "type": "steels-and-stainless",
  "summary": "Type 303 (UNS S30300, EN 1.4305) is the free-machining modification of the basic 18 percent chromium, 8 percent nickel austenitic stainless steel (Rolled Alloys). Sulphur, at least 0.15 percent, is added so that it machines more readily than 304/304L and 316/316L (Rolled Alloys), and Aalco calls it the most readily machined of the austenitic grades. The same sulphur costs corrosion resistance below 304 and weldability (Aalco).\n",
  "best_for": "Heavily machined parts in mild service, such as screws, nuts, bolts, shafts and fittings (Aalco, UPMET)",
  "weakest_at": "Chloride and marine service, where Aalco says 303 is not suitable, and welded joints, where Aalco says weldability is poor",
  "identity": {
    "formula": "Fe balance, 17.0 to 19.0 Cr, 8.0 to 10.0 Ni, max 0.15 C, max 2.0 Mn, max 0.20 P, min 0.15 S, max 1.0 Si, max 0.6 Mo (optional), wt%",
    "designations": [
      {
        "system": "UNS",
        "code": "S30300",
        "source": "rolled-303",
        "where": "Specifications line, UNS: S30300"
      },
      {
        "system": "EN",
        "code": "1.4305",
        "source": "rolled-303",
        "where": "Specifications line, W. Nr./EN: 1.4305"
      },
      {
        "system": "ASTM",
        "code": "A582",
        "note": "bar products",
        "source": "aalco-303",
        "where": "Property data note: typical for bar products covered by ASTM A582"
      },
      {
        "system": "ASTM",
        "code": "A581",
        "note": "listed on the wire data sheet",
        "source": "ulbrich-303",
        "where": "Header list: AMS 5640, ASTM A314, ASTM A581, ASTM A582, QQ-S-764"
      },
      {
        "system": "ASTM",
        "code": "A895",
        "note": "plate, from the UPMET data sheet title",
        "source": "upmet-303",
        "where": "Data sheet title: Plate - UNS S30300 - ASTM-A-895"
      },
      {
        "system": "AMS",
        "code": "5640",
        "source": "upmet-303",
        "where": "Header line: AMS 5640 (Chem Only) / UNS S30300"
      },
      {
        "system": "AISI",
        "code": "303",
        "source": "outokumpu-global",
        "where": "Table 4, ASTM column, 4305 row"
      },
      {
        "system": "JIS",
        "code": "SUS 303",
        "source": "outokumpu-global",
        "where": "Table 4, JIS column, 4305 row"
      },
      {
        "system": "ISO",
        "code": "4305-303-00-I",
        "source": "outokumpu-global",
        "where": "Table 5, ISO column, 4305 row"
      },
      {
        "system": "BS",
        "code": "303S31",
        "source": "outokumpu-global",
        "where": "Table 5, BS/UK column, 4305 row"
      },
      {
        "system": "AFNOR",
        "code": "Z8 CNF 18-09",
        "source": "outokumpu-global",
        "where": "Table 5, NF/France column, 4305 row"
      },
      {
        "system": "SS",
        "code": "2346",
        "source": "outokumpu-global",
        "where": "Table 5, SS/Sweden column, 4305 row"
      },
      {
        "system": "GB",
        "code": "Y1Cr18Ni9",
        "source": "outokumpu-global",
        "where": "Table 5, GB/PR China column, 4305 row"
      },
      {
        "system": "GOST",
        "code": "12X18H10E",
        "source": "outokumpu-global",
        "where": "Table 5, GOST/Russia column, 4305 row"
      }
    ],
    "source": "rolled-303",
    "where": "Chemical Composition table, MIN and MAX rows (UNS S30300)"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "structures",
      "mechanisms"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "value": 7.9,
      "bound": "exact",
      "unit": "kg/dm3",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not stated",
        "temperature": "room temperature (RT)"
      },
      "method": "Physical properties table (Table 13), density value at RT for the 1.4305 row",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 13, 4305 row, density RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "density",
      "value": 7.89,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "plate (UPMET ASTM A895 data sheet)",
        "temper": "not printed",
        "temperature": "not printed"
      },
      "method": "Physical Properties table, density row, printed as 7.89 g/cm3 beside 0.289 lb/in3",
      "status": "ground",
      "source": "upmet-303",
      "where": "Physical Properties table, Density g/cm3 row",
      "source_detail": {
        "title": "United Performance Metals: Datasheet for 303 Stainless Steel Plate (UNS S30300, ASTM-A-895)",
        "id": "303-.pdf",
        "url": "https://www.upmet.com/sites/default/files/datasheets/303-.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "density",
      "value": 8,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "wire (Ulbrich wire data sheet)",
        "temper": "not printed",
        "temperature": "not printed"
      },
      "method": "Physical properties line, printed as 0.283 lb/in3, 8.00 g/cm3",
      "status": "ground",
      "source": "ulbrich-303",
      "where": "Physical Properties, Density line",
      "source_detail": {
        "title": "Ulbrich: 303 Stainless Steel, UNS S30300 wire data sheet",
        "id": "303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "url": "https://www.ulbrich.com/uploads/data-sheets/303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "density",
      "value": 8.03,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "bar (Aalco note: typical for ASTM A582 bar products)",
        "temper": "not printed",
        "temperature": "not printed"
      },
      "method": "Typical Physical Properties table, density row, as printed",
      "status": "ground",
      "source": "aalco-303",
      "where": "Typical Physical Properties table, Density row",
      "source_detail": {
        "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
        "id": "26031.pdf",
        "url": "https://www.farnell.com/datasheets/26031.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "value": 1455,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "bar (Aalco typical data)",
        "temper": "not printed",
        "temperature": "one typical value, not a range"
      },
      "method": "Typical Physical Properties table, Melting Point row, printed in °C",
      "status": "ground",
      "source": "aalco-303",
      "where": "Typical Physical Properties table, Melting Point row",
      "source_detail": {
        "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
        "id": "26031.pdf",
        "url": "https://www.farnell.com/datasheets/26031.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "value": 1400,
      "value_high": 1420,
      "bound": "range",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "wire (Ulbrich wire data sheet)",
        "temper": "not printed",
        "temperature": "melting range"
      },
      "method": "Physical properties line, Melting Range row, printed as 2550-2590 F (1400-1420 C)",
      "status": "ground",
      "source": "ulbrich-303",
      "where": "Physical Properties, Melting Range row",
      "source_detail": {
        "title": "Ulbrich: 303 Stainless Steel, UNS S30300 wire data sheet",
        "id": "303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "url": "https://www.ulbrich.com/uploads/data-sheets/303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "value": 193,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "bar (Aalco typical data)",
        "temper": "not printed",
        "temperature": "in tension, temperature not stated"
      },
      "method": "Typical Physical Properties table, Modulus of Elasticity row, printed as 193 GPa",
      "status": "ground",
      "source": "aalco-303",
      "where": "Typical Physical Properties table, Modulus of Elasticity row",
      "source_detail": {
        "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
        "id": "26031.pdf",
        "url": "https://www.farnell.com/datasheets/26031.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "value": 200,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not stated",
        "temperature": "room temperature (RT)"
      },
      "method": "Physical properties table (Table 13), modulus of elasticity E, RT column",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 13, 4305 row, E RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "value": 15,
      "bound": "exact",
      "unit": "W/m°C",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not stated",
        "temperature": "room temperature (RT)"
      },
      "method": "Physical properties table (Table 13), thermal conductivity RT column",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 13, 4305 row, thermal conductivity RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "value": 20,
      "bound": "exact",
      "unit": "W/m°C",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not stated",
        "temperature": "400 C"
      },
      "method": "Physical properties table (Table 13), thermal conductivity 400 C column",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 13, 4305 row, thermal conductivity 400 C column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "value": 16.2,
      "bound": "exact",
      "unit": "W/m-°K",
      "scope": "material",
      "conditions": {
        "form": "plate (UPMET ASTM A895 data sheet)",
        "temper": "not printed",
        "temperature": "100 C (212 F)"
      },
      "method": "Physical Properties table, thermal conductivity at 212 F (100 C), as printed",
      "status": "ground",
      "source": "upmet-303",
      "where": "Physical Properties table, Thermal Conductivity row",
      "source_detail": {
        "title": "United Performance Metals: Datasheet for 303 Stainless Steel Plate (UNS S30300, ASTM-A-895)",
        "id": "303-.pdf",
        "url": "https://www.upmet.com/sites/default/files/datasheets/303-.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "value": 16.3,
      "bound": "exact",
      "unit": "W/m.K",
      "scope": "material",
      "conditions": {
        "form": "bar (Aalco typical data)",
        "temper": "not printed",
        "temperature": "100 C"
      },
      "method": "Typical Physical Properties table, Thermal Conductivity row, printed as 16.3 W/m.K at 100 C",
      "status": "ground",
      "source": "aalco-303",
      "where": "Typical Physical Properties table, Thermal Conductivity row",
      "source_detail": {
        "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
        "id": "26031.pdf",
        "url": "https://www.farnell.com/datasheets/26031.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "specific_heat",
      "value": 500,
      "bound": "exact",
      "unit": "J/kg°C",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not stated",
        "temperature": "room temperature (RT)"
      },
      "method": "Physical properties table (Table 13), thermal capacity c RT column",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 13, 4305 row, thermal capacity RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "specific_heat",
      "value": 0.5,
      "bound": "exact",
      "unit": "J/g-°C",
      "scope": "material",
      "conditions": {
        "form": "wire (Ulbrich wire data sheet)",
        "temper": "not printed",
        "temperature": "0 to 100 C (32 to 212 F)"
      },
      "method": "Specific Heat line, printed as 0.12 (0.5) BTU/lb-F and J/g-C for 32 to 212 F",
      "status": "ground",
      "source": "ulbrich-303",
      "where": "Specific Heat line, 32-212 F (0-100 C)",
      "source_detail": {
        "title": "Ulbrich: 303 Stainless Steel, UNS S30300 wire data sheet",
        "id": "303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "url": "https://www.ulbrich.com/uploads/data-sheets/303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "value": 16,
      "bound": "exact",
      "unit": "10-6/°C",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not stated",
        "temperature": "20 to 100 C (mean between 20 C and T)"
      },
      "method": "Physical properties table (Table 13), coefficient of thermal expansion at 100 C column",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 13, 4305 row, CTE 100 C column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "value": 17.5,
      "bound": "exact",
      "unit": "10-6/°C",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not stated",
        "temperature": "20 to 400 C (mean between 20 C and T)"
      },
      "method": "Physical properties table (Table 13), coefficient of thermal expansion at 400 C column",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 13, 4305 row, CTE 400 C column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "value": 16.7,
      "bound": "exact",
      "unit": "µm/m-°C",
      "scope": "material",
      "conditions": {
        "form": "wire (Ulbrich wire data sheet)",
        "temper": "not printed",
        "temperature": "20 to 200 C (mean, 68 to 392 F)"
      },
      "method": "Mean Coefficient of Thermal Expansion line, printed as 9.3 (16.7) in the 68-392 F (20-200 C) row",
      "status": "ground",
      "source": "ulbrich-303",
      "where": "Mean Coefficient of Thermal Expansion line, 68-392 F (20-200 C)",
      "source_detail": {
        "title": "Ulbrich: 303 Stainless Steel, UNS S30300 wire data sheet",
        "id": "303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "url": "https://www.ulbrich.com/uploads/data-sheets/303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "value": 17.3,
      "bound": "exact",
      "unit": "10-6/K",
      "scope": "material",
      "conditions": {
        "form": "bar (Aalco typical data)",
        "temper": "not printed",
        "temperature": "100 C (averaging basis not stated)"
      },
      "method": "Typical Physical Properties table, Thermal Expansion row, printed as 17.3x10-6 /K at 100 C",
      "status": "ground",
      "source": "aalco-303",
      "where": "Typical Physical Properties table, Thermal Expansion row",
      "source_detail": {
        "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
        "id": "26031.pdf",
        "url": "https://www.farnell.com/datasheets/26031.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "value": 72,
      "bound": "exact",
      "unit": "microhm-cm",
      "scope": "material",
      "conditions": {
        "form": "plate (UPMET ASTM A895 data sheet)",
        "temper": "not printed",
        "temperature": "20 C"
      },
      "method": "Physical Properties table, Electrical Resistivity row, printed as 72.0 Microhm-cm at 20 C",
      "status": "ground",
      "source": "upmet-303",
      "where": "Physical Properties table, Electrical Resistivity row",
      "source_detail": {
        "title": "United Performance Metals: Datasheet for 303 Stainless Steel Plate (UNS S30300, ASTM-A-895)",
        "id": "303-.pdf",
        "url": "https://www.upmet.com/sites/default/files/datasheets/303-.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "value": 0.73,
      "bound": "exact",
      "unit": "μΩm",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not stated",
        "temperature": "room temperature (RT)"
      },
      "method": "Physical properties table (Table 13), electrical resistivity RT column",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 13, 4305 row, electrical resistivity RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 172,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "wire (Ulbrich wire data sheet)",
        "temper": "annealed (Annealed Typical block)",
        "temperature": "room temperature",
        "basis": "minimum, printed as 25 KSI min (172 MPa min)"
      },
      "method": "Mechanical Properties at Room Temperature, Annealed Typical block, Yield Strength line",
      "status": "ground",
      "source": "ulbrich-303",
      "where": "Mechanical Properties at Room Temperature, Yield Strength line",
      "source_detail": {
        "title": "Ulbrich: 303 Stainless Steel, UNS S30300 wire data sheet",
        "id": "303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "url": "https://www.ulbrich.com/uploads/data-sheets/303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 205,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "hot rolled plate, transverse (Table 7 note: EN and ASTM min values are mainly for this product)",
        "temper": "not printed",
        "temperature": "room temperature (RT)",
        "basis": "minimum, ASTM"
      },
      "method": "Table 7, ASTM min values at RT, Rp0.2 column, S30300 row",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 7, 4305 row, ASTM min Rp0.2 column (S30300)",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 190,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "hot rolled plate, transverse (Table 7 note: EN and ASTM min values are mainly for this product)",
        "temper": "not printed",
        "temperature": "room temperature (RT)",
        "basis": "minimum, EN"
      },
      "method": "Table 7, EN min values at RT, Rp0.2 column, 1.4305 row",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 7, 4305 row, EN min Rp0.2 column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 190,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "bar (Aalco note: typical for ASTM A582 bar products)",
        "temper": "not printed",
        "temperature": "not printed",
        "basis": "typical, 0.2 percent proof stress"
      },
      "method": "Mechanical properties table, Proof Stress 0.2 percent row, printed as 190 MPa",
      "status": "ground",
      "source": "aalco-303",
      "where": "Mechanical properties table, Proof Stress 0.2 percent (MPa) row",
      "source_detail": {
        "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
        "id": "26031.pdf",
        "url": "https://www.farnell.com/datasheets/26031.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 30,
      "bound": "exact",
      "unit": "ksi",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not printed in this row",
        "temperature": "not stated",
        "basis": "typical"
      },
      "method": "Typical Tensile Properties table, Yield Strength row, printed in ksi",
      "status": "ground",
      "source": "rolled-303",
      "where": "Mechanical Properties, Typical Tensile Properties, Yield Strength row",
      "source_detail": {
        "title": "Rolled Alloys: 303 Stainless Steel Data Sheet (Bulletin No. 1355)",
        "id": "303_stainless-steel-data-sheet-rolled-alloys.pdf",
        "url": "https://www.rolledalloys.com/wp-content/uploads/303_stainless-steel-data-sheet-rolled-alloys.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "value": 517,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "wire (Ulbrich wire data sheet)",
        "temper": "annealed (Annealed Typical block)",
        "temperature": "room temperature",
        "basis": "minimum, printed as 75 KSI min (517 MPa min)"
      },
      "method": "Mechanical Properties at Room Temperature, Annealed Typical block, Ultimate Tensile Strength line",
      "status": "ground",
      "source": "ulbrich-303",
      "where": "Mechanical Properties at Room Temperature, Ultimate Tensile Strength line",
      "source_detail": {
        "title": "Ulbrich: 303 Stainless Steel, UNS S30300 wire data sheet",
        "id": "303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "url": "https://www.ulbrich.com/uploads/data-sheets/303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "value": 515,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "hot rolled plate, transverse (Table 7 note: EN and ASTM min values are mainly for this product)",
        "temper": "not printed",
        "temperature": "room temperature (RT)",
        "basis": "minimum, ASTM"
      },
      "method": "Table 7, ASTM min values at RT, Rm column, S30300 row",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 7, 4305 row, ASTM min Rm column (S30300)",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "value": 500,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "hot rolled plate, transverse (Table 7 note: EN and ASTM min values are mainly for this product)",
        "temper": "not printed",
        "temperature": "room temperature (RT)",
        "basis": "minimum, EN"
      },
      "method": "Table 7, EN min values at RT, Rm column, 1.4305 row",
      "status": "ground",
      "source": "outokumpu-global",
      "where": "Table 7, 4305 row, EN min Rm column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "handbook",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "value": 500,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "bar (Aalco note: typical for ASTM A582 bar products)",
        "temper": "not printed",
        "temperature": "not printed",
        "basis": "typical"
      },
      "method": "Mechanical properties table, Tensile Strength (MPa) row, printed as 500",
      "status": "ground",
      "source": "aalco-303",
      "where": "Mechanical properties table, Tensile Strength (MPa) row",
      "source_detail": {
        "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
        "id": "26031.pdf",
        "url": "https://www.farnell.com/datasheets/26031.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "value": 75,
      "bound": "exact",
      "unit": "ksi",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not printed in this row",
        "temperature": "not stated",
        "basis": "typical"
      },
      "method": "Typical Tensile Properties table, Tensile Strength row, printed in ksi",
      "status": "ground",
      "source": "rolled-303",
      "where": "Mechanical Properties, Typical Tensile Properties, Tensile Strength row",
      "source_detail": {
        "title": "Rolled Alloys: 303 Stainless Steel Data Sheet (Bulletin No. 1355)",
        "id": "303_stainless-steel-data-sheet-rolled-alloys.pdf",
        "url": "https://www.rolledalloys.com/wp-content/uploads/303_stainless-steel-data-sheet-rolled-alloys.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "value": 35,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "wire (Ulbrich wire data sheet)",
        "temper": "annealed (Annealed Typical block)",
        "temperature": "room temperature",
        "gauge": "not printed",
        "basis": "minimum, printed as 35 % min"
      },
      "method": "Mechanical Properties at Room Temperature, Annealed Typical block, Elongation line",
      "status": "ground",
      "source": "ulbrich-303",
      "where": "Mechanical Properties at Room Temperature, Elongation line",
      "source_detail": {
        "title": "Ulbrich: 303 Stainless Steel, UNS S30300 wire data sheet",
        "id": "303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "url": "https://www.ulbrich.com/uploads/data-sheets/303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
        "year": 2015,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "value": 35,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "not stated",
        "temper": "not printed in this row",
        "temperature": "not stated",
        "gauge": "2 inches (printed as % Elongation in 2 inches)",
        "basis": "typical"
      },
      "method": "Typical Tensile Properties table, % Elongation in 2 inches row",
      "status": "ground",
      "source": "rolled-303",
      "where": "Mechanical Properties, Typical Tensile Properties, % Elongation in 2 inches row",
      "source_detail": {
        "title": "Rolled Alloys: 303 Stainless Steel Data Sheet (Bulletin No. 1355)",
        "id": "303_stainless-steel-data-sheet-rolled-alloys.pdf",
        "url": "https://www.rolledalloys.com/wp-content/uploads/303_stainless-steel-data-sheet-rolled-alloys.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "value": 35,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "bar (Aalco note: typical for ASTM A582 bar products)",
        "temper": "not printed",
        "temperature": "not printed",
        "gauge": "A5 (printed as Elongation A5)",
        "basis": "typical"
      },
      "method": "Mechanical properties table, Elongation A5 (%) row, printed as 35",
      "status": "ground",
      "source": "aalco-303",
      "where": "Mechanical properties table, Elongation A5 (%) row",
      "source_detail": {
        "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
        "id": "26031.pdf",
        "url": "https://www.farnell.com/datasheets/26031.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "hardness",
      "value": 202,
      "bound": "upper",
      "unit": "HBN",
      "scope": "material",
      "conditions": {
        "form": "plate (UPMET ASTM A895 data sheet)",
        "temper": "not printed",
        "temperature": "not printed",
        "basis": "maximum, printed as Max 202 (HBN)"
      },
      "method": "Mechanical Properties table, Hardness row, Max 202 (HBN) as printed",
      "status": "ground",
      "source": "upmet-303",
      "where": "Mechanical Properties table, Hardness row",
      "source_detail": {
        "title": "United Performance Metals: Datasheet for 303 Stainless Steel Plate (UNS S30300, ASTM-A-895)",
        "id": "303-.pdf",
        "url": "https://www.upmet.com/sites/default/files/datasheets/303-.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Mild environments",
      "headline": "Corrosion resistance remains good in mild environments (Aalco).",
      "effect": "Aalco says sulphur lowers corrosion resistance to less than that of 304, but corrosion resistance remains good in mild environments.",
      "rating": "low",
      "conditions": {
        "environment": "mild environments, as printed",
        "temperature": "not stated"
      },
      "source": "aalco-303",
      "where": "Corrosion Resistance section"
    },
    {
      "environment": "Compared with Type 304",
      "headline": "Sulphur gives pitting initiation sites, so 303 resists less than 304.",
      "effect": "Aalco says sulphur additions act as initiation sites for pitting corrosion, which decreases the corrosion resistance of 303 to less than that for 304.",
      "rating": "moderate",
      "conditions": {
        "comparison": "Type 304",
        "temperature": "not stated"
      },
      "source": "aalco-303",
      "where": "Corrosion Resistance section, first sentences"
    },
    {
      "environment": "Chloride-containing environments above 60 C",
      "headline": "Pitting and crevice corrosion in chloride environments over 60 C.",
      "effect": "Aalco says that in chloride containing environments over 60 C, 303 is subject to pitting and crevice corrosion.",
      "rating": "moderate",
      "conditions": {
        "environment": "chloride containing",
        "temperature": "over 60 C"
      },
      "source": "aalco-303",
      "where": "Corrosion Resistance section"
    },
    {
      "environment": "Marine environments",
      "headline": "Not suitable for marine use (Aalco).",
      "effect": "Aalco says grade 303 stainless steel is not suitable for use in marine environments.",
      "rating": "severe",
      "conditions": {
        "environment": "marine",
        "temperature": "not stated"
      },
      "source": "aalco-303",
      "where": "Corrosion Resistance section, last sentence"
    },
    {
      "environment": "Continuous use at 425 to 860 C",
      "headline": "Sensitive to carbide precipitation in continuous service at 425 to 860 C.",
      "effect": "Aalco says continuous service at 870 C is not recommended because 303 is sensitive to carbide precipitation with continuous use at 425 to 860 C.",
      "rating": "moderate",
      "conditions": {
        "temperature": "425 to 860 C continuous use"
      },
      "source": "aalco-303",
      "where": "Heat Resistance section"
    },
    {
      "environment": "Oxidation in air at high temperature",
      "headline": "Good oxidation resistance, intermittent to 760 C and continuous to 870 C.",
      "effect": "Aalco says 303 has good resistance to oxidation when intermittently exposed to temperatures up to 760 C, and good oxidation resistance in continuous service to 870 C.",
      "rating": "low",
      "conditions": {
        "temperature": "intermittent up to 760 C; continuous to 870 C"
      },
      "source": "aalco-303",
      "where": "Heat Resistance section"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem aggregated GHS notifications for elemental nickel include H317 (may cause an allergic skin reaction), H351 (suspected of causing cancer), H372 (causes damage to organs through prolonged or repeated exposure), H334 (may cause allergy or asthma symptoms or breathing difficulties if inhaled) and H412 (harmful to aquatic life with long lasting effects). These cover the element, not the 303 alloy.",
        "ghs": [
          "H317",
          "H351",
          "H372",
          "H334",
          "H412"
        ],
        "source": "pubchem-nickel",
        "where": "GHS Classification, aggregated notifications (CID 935)"
      },
      {
        "text": "PubChem notifications for elemental chromium include H317 (may cause an allergic skin reaction), H319 (causes serious eye irritation), H334 (may cause allergy or asthma symptoms or breathing difficulties if inhaled) and H341 (suspected of causing genetic defects). These cover the element, not the alloy.",
        "ghs": [
          "H317",
          "H319",
          "H334",
          "H341"
        ],
        "source": "pubchem-chromium",
        "where": "GHS Classification, notifications (CID 23976)"
      },
      {
        "text": "PubChem notifications for elemental manganese include H372 (causes damage to organs through prolonged or repeated exposure), H360 (may damage fertility or the unborn child), H370 (causes damage to organs), H228 (flammable solid, 11.6 percent share in the notifications) and H411 (toxic to aquatic life with long lasting effects).",
        "ghs": [
          "H372",
          "H360",
          "H370",
          "H228",
          "H411"
        ],
        "source": "pubchem-manganese",
        "where": "GHS Classification, notifications (CID 23930)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Pitting and crevice corrosion at the sulphur additions",
        "trigger": "Chloride-containing environment above 60 C, or marine service",
        "consequence": "Aalco says 303 is subject to pitting and crevice corrosion in chloride above 60 C and is not suitable for marine environments",
        "severity": "high",
        "source": "aalco-303",
        "where": "Corrosion Resistance section"
      },
      {
        "mode": "Poor weldability from the sulphur addition",
        "trigger": "Fusion welding of 303 parts",
        "consequence": "Aalco says the sulphur addition results in poor weldability, and recommends 308L or 309 filler and annealed welds",
        "severity": "moderate",
        "source": "aalco-303",
        "where": "Welding section"
      },
      {
        "mode": "Carbide precipitation (sensitisation)",
        "trigger": "Continuous use at 425 to 860 C",
        "consequence": "Aalco says 303 is sensitive to carbide precipitation, and continuous service at 870 C is not recommended",
        "severity": "moderate",
        "source": "aalco-303",
        "where": "Heat Resistance section"
      },
      {
        "mode": "Slightly lower toughness",
        "trigger": "The sulphur addition",
        "consequence": "Aalco says sulphur causes a slight lowering of the toughness",
        "severity": "low",
        "source": "aalco-303",
        "where": "Opening paragraph"
      },
      {
        "mode": "Poor cold formability",
        "trigger": "Sharp bending or cold working",
        "consequence": "Aalco says type 303 is not readily cold workable and sharp bending should not be attempted",
        "severity": "moderate",
        "source": "aalco-303",
        "where": "Cold Working section"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Keep cutting edges sharp, make cuts light but deep enough to avoid work hardening, use chip breakers, and use coolants and lubricants in large quantities (Aalco).",
        "source": "aalco-303",
        "where": "Machining section"
      },
      {
        "text": "Rolled Alloys gives starting speeds of 65 to 75 sfpm for twist drills in annealed type 303 with high speed tooling, at feeds of 0.0045 to 0.0055 inch per revolution.",
        "source": "rolled-303",
        "where": "Feeds and Speeds table, Twisting Drill rows"
      },
      {
        "text": "Use tooling and work surfaces dedicated to stainless steel, and clean them before use, to avoid contamination (Aalco).",
        "source": "aalco-303",
        "where": "Fabrication section"
      },
      {
        "text": "Not hardenable by heat treatment; solution treatment or annealing by rapid cooling after heating to 1010 to 1120 C (Aalco).",
        "source": "aalco-303",
        "where": "Heat Treatment section"
      },
      {
        "text": "Hot working after uniform heating to 1149 to 1260 C, then rapid cooling of the fabricated components for maximum corrosion resistance (Aalco).",
        "source": "aalco-303",
        "where": "Hot Working section"
      },
      {
        "text": "Type 303 is not readily cold workable, and sharp bending should not be attempted (Aalco).",
        "source": "aalco-303",
        "where": "Cold Working section"
      }
    ],
    "mitigations": [
      {
        "text": "If 303 must be welded, use 308L or 309 stainless steel filler rods or electrodes (Aalco).",
        "source": "aalco-303",
        "where": "Welding section"
      },
      {
        "text": "Anneal the welds for maximum corrosion resistance (Aalco).",
        "source": "aalco-303",
        "where": "Welding section"
      }
    ]
  },
  "uses": [
    {
      "application": "structures",
      "device": "Nuts, bolts and screws",
      "example": "Aalco lists nuts and bolts and screws among the applications that need parts heavily machined.",
      "source": "aalco-303",
      "where": "Applications list"
    },
    {
      "application": "structures",
      "device": "Aircraft fittings",
      "example": "UPMET lists aircraft applications including fittings, shafts and spindles; Aalco lists aircraft fittings.",
      "source": "upmet-303",
      "where": "Industry Applications list"
    },
    {
      "application": "mechanisms",
      "device": "Shafts, gears and bushings",
      "example": "Aalco lists gears, bushings and shafts; UPMET lists shafts and spindles.",
      "source": "aalco-303",
      "where": "Applications list"
    },
    {
      "application": "mechanisms",
      "device": "Automatic screw machine parts",
      "example": "UPMET lists automatic screw machine applications; Rolled Alloys also lists automatic screw machines.",
      "source": "upmet-303",
      "where": "Industry Applications list"
    }
  ],
  "supply": [
    {
      "subject": "Chromium production by country",
      "abundance": "World mine production was 51,000 thousand metric tons (gross weight) in 2025e, against 49,600 in 2024. World resources are greater than 12 billion tons of shipping-grade chromite, 95 percent in Kazakhstan and southern Africa. Shares are for the six largest producers, computed from the printed 2025e tonnage over the 51,000 world total.",
      "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
        },
        {
          "country": "Brazil",
          "share_percent": 3.9,
          "year": 2025
        },
        {
          "country": "Zimbabwe",
          "share_percent": 3.9,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "In 2025, recycled chromium in reported stainless-steel scrap receipts accounted for 21 percent of apparent consumption.",
      "substitutes": [
        "Chromium has no substitute in stainless steel, the leading end use (USGS 2026)."
      ],
      "source": "usgs-chromium-2026",
      "where": "World Mine Production and Reserves table (2025e column); World Resources; Substitutes; Recycling"
    },
    {
      "subject": "Chromium import reliance",
      "abundance": "US net import reliance was 79 percent of apparent consumption in 2025e (76 percent in 2021). Chromite ore imports for 2021 to 2024 came from South Africa (96 percent), Turkey (3 percent) and other sources (1 percent).",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "usgs-chromium-2026",
      "where": "Salient Statistics, net import reliance row (2025e); Import Sources (2021-24)"
    },
    {
      "subject": "Nickel production by country",
      "abundance": "World nickel mine production was an estimated 3.9 million tons in 2025, up 5 percent from 2024. World reserves are printed as more than 140,000,000, of which Indonesia holds 62,000,000. Shares are for the six largest producers, computed from the printed 2025e tonnage over the 3.9 million world total.",
      "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
        },
        {
          "country": "China",
          "share_percent": 3.1,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "In 2025, nickel recovered from scrap accounted for approximately 60 percent of apparent consumption.",
      "substitutes": [
        "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 column); Recycling; Substitutes"
    },
    {
      "subject": "Nickel use and US import reliance",
      "abundance": "Stainless and alloy steel and nickel-containing alloys typically account for more than 85 percent of domestic consumption. US net import reliance was 41 percent of apparent consumption in 2025e (38 percent in 2021).",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "usgs-nickel-2026",
      "where": "Salient Statistics, net import reliance row (2025e); Domestic Production and Use"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
      "type": "datasheet",
      "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf"
    },
    {
      "title": "Rolled Alloys: 303 Stainless Steel Data Sheet (Bulletin No. 1355)",
      "type": "datasheet",
      "url": "https://www.rolledalloys.com/wp-content/uploads/303_stainless-steel-data-sheet-rolled-alloys.pdf"
    },
    {
      "title": "United Performance Metals: Datasheet for 303 Stainless Steel Plate (UNS S30300, ASTM-A-895)",
      "type": "datasheet",
      "url": "https://www.upmet.com/sites/default/files/datasheets/303-.pdf",
      "year": 2026
    },
    {
      "title": "Ulbrich: 303 Stainless Steel, UNS S30300 wire data sheet",
      "type": "datasheet",
      "url": "https://www.ulbrich.com/uploads/data-sheets/303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
      "year": 2015
    },
    {
      "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
      "type": "datasheet",
      "url": "https://www.farnell.com/datasheets/26031.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": "PubChem: Nickel (CID 935), UN GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/935/JSON"
    },
    {
      "title": "PubChem: Chromium (CID 23976), UN GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON"
    },
    {
      "title": "PubChem: Manganese (CID 23930), UN GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23930/JSON"
    }
  ],
  "gaps": [
    "Weldability comes from one source only (Aalco): the sulphur addition gives poor weldability, with 308L or 309 filler. No weld-metal, weld toughness or weld cracking test was read.",
    "Composition conflicts: carbon maximum is 0.15 in Rolled Alloys and Aalco but 0.12 in Ulbrich, which also gives sulphur 0.150 minimum. UPMET prints sulphur 0.15 to 0.35, and its carbon and manganese maxima sit in a column the PDF text does not label, so they are taken from Rolled Alloys and Aalco. Rolled Alloys and Aalco print no sulphur maximum.",
    "Density: UPMET prints 7.89 g/cm3 beside 0.289 lb/in3, which does not agree with Ulbrich (8.00 g/cm3) or Aalco (8.03 g/cm3). All four values are kept with their own form.",
    "Melting point: Aalco prints one value (1455 C) and Ulbrich prints a range (1400 to 1420 C). UPMET prints 2552 F only, and it is not converted here.",
    "Hardness is not in the canonical property list, so the short name hardness is used. Only UPMET prints a value (202 HBN maximum, plate). Aalco prints 262max against the label Hardness Rockwell (HB), which is ambiguous, so it is not used.",
    "EN name X8CrNiS18-9 was not printed on any page read in this run, so the EN entry is the number 1.4305 only.",
    "SAE 30303 was not printed on any page read in this run, so it is not listed.",
    "The selenium-bearing variant (303Se) was not read and is not listed as an alias.",
    "Machinability is given as Rolled Alloys starting speeds and as qualitative statements (Aalco, Rolled Alloys, Ulbrich). No machinability rating index was printed on any page read.",
    "Outokumpu typical values apply to hot rolled plate; EN and ASTM minimums are mainly for hot rolled plate in the transverse direction (Table 7 note). Rolled Alloys and Aalco print typical values with no temper. Ulbrich gives annealed values for wire.",
    "Elevated-temperature and cryogenic strength values for 303 were not read. Poisson's ratio, shear modulus and bulk modulus were not printed on the pages read.",
    "Corrosion ratings are judgements on printed text, not test results. No pitting resistance number (PREN) was printed on the pages read.",
    "No safety data sheet for 303 was read. The hazards are PubChem GHS notifications for elemental nickel, chromium and manganese, not a supplier classification.",
    "Supply shares are computed from printed 2025e tonnage; refinery and smelter shares were not read. No EU or BGS critical-mineral list was read, so critical_lists is empty.",
    "No NASA or ESA source naming 303 in a spacecraft part was read, so the space link is not sourced.",
    "The web search budget for this turn ran out, so no ATI, Carpenter, AK Steel or Cleveland-Cliffs, AZoM or other 303 product page was reached."
  ],
  "story": {
    "why": "Type 303 is the free-machining version of the basic 18 percent chromium, 8 percent nickel stainless steel. Sulphur makes it the most readily machined of the austenitic grades (Aalco), and the price is lower corrosion resistance than 304 and poor weldability (Aalco). Aalco says the toughness is still excellent, though sulphur lowers it slightly. Rolled Alloys says the grade is non-magnetic and not hardenable by heat treatment.",
    "uses": [
      {
        "where": "Nuts, bolts and screws",
        "line": "Aalco lists them among the applications that need parts heavily machined."
      },
      {
        "where": "Aircraft fittings, shafts and spindles",
        "line": "UPMET lists aircraft applications including fittings, shafts and spindles; Aalco lists aircraft fittings."
      },
      {
        "where": "Gears and bushings",
        "line": "Aalco lists gears and bushings among its typical applications."
      },
      {
        "where": "Automatic screw machine parts",
        "line": "UPMET lists automatic screw machine applications, and Rolled Alloys lists automatic screw machines."
      }
    ],
    "can_do": [
      {
        "label": "Strength",
        "line": "Ulbrich gives a 517 MPa minimum for annealed wire. Aalco gives a typical 500 MPa for bar.",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Yield",
        "line": "Ulbrich gives a 172 MPa minimum for annealed wire. Outokumpu gives minimums of 190 MPa (EN) and 205 MPa (ASTM) for hot rolled plate.",
        "benchmark": "yield_strength",
        "scope": "material"
      },
      {
        "label": "Stiffness",
        "line": "Elastic modulus is 193 GPa (Aalco) and 200 GPa at room temperature (Outokumpu).",
        "benchmark": "elastic_modulus",
        "scope": "material"
      },
      {
        "label": "Density",
        "line": "Density is 7.89 g/cm3 (UPMET) to 8.03 g/cm3 (Aalco) across the datasheets; Ulbrich gives 8.00 g/cm3.",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Machining",
        "line": "Rolled Alloys gives starting speeds of 65 to 75 sfpm for twist drills in annealed type 303, at feeds of 0.0045 to 0.0055 inch per revolution.",
        "scope": "material"
      }
    ],
    "compare": "Against 304, type 303 machines more readily, which Aalco ties to its sulphur, and it resists corrosion less, because sulphur gives pitting initiation sites (Aalco). Aalco also calls its weldability poor. Rolled Alloys says 303 has improved machinability over 304/304L and 316/316L. No 304 or 316 composition or property values were read in this run, so none are compared as numbers.",
    "compare_rows": [
      {
        "label": "Tensile strength",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Melting point",
        "benchmark": "melting_point",
        "scope": "material"
      }
    ],
    "handling": [
      "Keep cutting edges sharp and use light but deep cuts with chip breakers; use coolants and lubricants in large quantities (Aalco).",
      "Rolled Alloys gives starting speeds of 65 to 75 sfpm for twist drills on annealed type 303, at feeds of 0.0045 to 0.0055 inch per revolution.",
      "Use tooling dedicated to stainless steel (Aalco).",
      "Not hardenable by heat treatment; anneal by rapid cooling from 1010 to 1120 C (Aalco).",
      "If it must be welded, use 308L or 309 filler and anneal the welds (Aalco)."
    ],
    "good_for": [
      "Heavily machined parts such as nuts, bolts, screws, shafts, bushings and gears (Aalco, UPMET).",
      "Automatic screw machine work and aircraft fittings (UPMET).",
      "Mild-environment parts, where Aalco says corrosion resistance remains good."
    ],
    "watch_out": [
      "Chloride above 60 C and marine service: pitting and crevice corrosion, and Aalco says 303 is not suitable for marine environments.",
      "Welding: Aalco says the sulphur addition gives poor weldability.",
      "Continuous use at 425 to 860 C: sensitive to carbide precipitation (Aalco).",
      "Cold bending: not readily cold workable, and sharp bending should not be attempted (Aalco)."
    ],
    "verdict": "Aalco calls 303 the most readily machined of the austenitic grades. Its sulphur costs corrosion resistance below 304 and weldability, so use it for machined parts in mild service and not for marine use.",
    "recipe": {
      "line": "Type 303 is an iron-based austenitic stainless steel with 17.0 to 19.0 percent chromium and 8.0 to 10.0 percent nickel. Sulphur, at least 0.15 percent, is the free-machining addition (Rolled Alloys, Ulbrich, Aalco). The figures are datasheet limits in weight percent, not one heat's analysis.",
      "parts": [
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "The matrix of the alloy; Rolled Alloys calls 303 a non-magnetic austenitic stainless steel.",
          "share_note": "balance"
        },
        {
          "name": "Chromium",
          "symbol": "Cr",
          "role": "Chromium content of the basic 18 percent chromium, 8 percent nickel grade (Rolled Alloys).",
          "share_percent": 17,
          "share_high": 19,
          "source": "rolled-303",
          "where": "Chemical Composition table, MIN and MAX rows"
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Nickel content of the basic 18 percent chromium, 8 percent nickel grade (Rolled Alloys).",
          "share_percent": 8,
          "share_high": 10,
          "source": "rolled-303",
          "where": "Chemical Composition table, MIN and MAX rows"
        },
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Maximum limit only (Rolled Alloys and Aalco); Ulbrich prints 0.12.",
          "share_percent": 0,
          "share_high": 0.15,
          "source": "rolled-303",
          "where": "Chemical Composition table, MAX row"
        },
        {
          "name": "Manganese",
          "symbol": "Mn",
          "role": "Maximum limit only; the datasheets print no role for it.",
          "share_percent": 0,
          "share_high": 2,
          "source": "rolled-303",
          "where": "Chemical Composition table, MAX row"
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Maximum limit only; the datasheets print no role for it.",
          "share_percent": 0,
          "share_high": 1,
          "source": "rolled-303",
          "where": "Chemical Composition table, MAX row"
        },
        {
          "name": "Phosphorus",
          "symbol": "P",
          "role": "Maximum limit only; the datasheets print no role for it.",
          "share_percent": 0,
          "share_high": 0.2,
          "source": "rolled-303",
          "where": "Chemical Composition table, MAX row"
        },
        {
          "name": "Sulphur",
          "symbol": "S",
          "role": "Free-machining addition. It gives the machinability and costs corrosion resistance (Aalco).",
          "share_percent": 0.15,
          "share_note": "minimum; UPMET prints a maximum of 0.35",
          "source": "rolled-303",
          "where": "Chemical Composition table, MIN row"
        },
        {
          "name": "Molybdenum",
          "symbol": "Mo",
          "role": "Optional element, maximum 0.6 (Rolled Alloys).",
          "share_percent": 0,
          "share_high": 0.6,
          "source": "rolled-303",
          "where": "Chemical Composition table, MAX row (optional)"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The PubChem records are for elemental nickel, chromium and manganese, not for the 303 alloy. No safety data sheet for 303 was read.",
        "points": [
          {
            "label": "Nickel",
            "line": "PubChem lists elemental nickel with H317, H351, H372, H334 and H412 in its aggregated notifications."
          },
          {
            "label": "Chromium",
            "line": "PubChem lists elemental chromium with H317, H319, H334 and H341 in its notifications."
          },
          {
            "label": "Manganese",
            "line": "PubChem lists elemental manganese with H372, H360, H370, H228 and H411 in its notifications."
          }
        ],
        "level": 1,
        "verdict": "No SDS read; element notifications only"
      },
      {
        "title": "In the environment",
        "lead": "Pitting at the sulphur additions is the main failure route. Aalco says 303 is not suitable for marine environments.",
        "points": [
          {
            "label": "Chloride",
            "line": "Aalco says chloride-containing environments over 60 C cause pitting and crevice corrosion."
          },
          {
            "label": "Marine",
            "line": "Aalco says grade 303 stainless steel is not suitable for use in marine environments."
          }
        ],
        "level": 3,
        "verdict": "Chloride and marine service are the watch points"
      },
      {
        "title": "Welding and heat",
        "lead": "Aalco calls the weldability poor because of the sulphur addition, and says continuous use at 425 to 860 C causes carbide precipitation.",
        "points": [
          {
            "label": "Welding",
            "line": "The sulphur addition results in poor weldability. Use 308L or 309 filler, and anneal the welds for maximum corrosion resistance."
          },
          {
            "label": "Heat",
            "line": "Sensitive to carbide precipitation with continuous use at 425 to 860 C. Continuous service at 870 C is not recommended."
          }
        ],
        "level": 2,
        "verdict": "Sulphur and heat history set the risk"
      }
    ]
  },
  "updated": "2026-10-24",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 34,
    "unreachable": 0,
    "caveats": 5,
    "note": "Read by an AI assistant on 2026-10-24 from pages fetched in this run: Outokumpu global standards PDF (Tables 4, 5, 7 and 13), Rolled Alloys 303 data sheet, UPMET 303 data sheet, Ulbrich 303 wire data sheet, Aalco 1.4305 data sheet (PDF hosted by Farnell), USGS Mineral Commodity Summaries 2026 (nickel and chromium), and PubChem records for nickel, chromium and manganese. The web search budget for this turn was used up, so no other 303 page was read."
  },
  "sources": {
    "outokumpu-global": {
      "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 4, 5, 7 and 13)",
      "id": "outokumpu-steel-grades-properties-global-standards.pdf",
      "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
      "kind": "handbook",
      "license": "cited, not reproduced"
    },
    "rolled-303": {
      "title": "Rolled Alloys: 303 Stainless Steel Data Sheet (Bulletin No. 1355)",
      "id": "303_stainless-steel-data-sheet-rolled-alloys.pdf",
      "url": "https://www.rolledalloys.com/wp-content/uploads/303_stainless-steel-data-sheet-rolled-alloys.pdf",
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "upmet-303": {
      "title": "United Performance Metals: Datasheet for 303 Stainless Steel Plate (UNS S30300, ASTM-A-895)",
      "id": "303-.pdf",
      "url": "https://www.upmet.com/sites/default/files/datasheets/303-.pdf",
      "year": 2026,
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "ulbrich-303": {
      "title": "Ulbrich: 303 Stainless Steel, UNS S30300 wire data sheet",
      "id": "303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
      "url": "https://www.ulbrich.com/uploads/data-sheets/303-Stainless-Steel-Wire-UNS-S30300-wire.pdf",
      "year": 2015,
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "aalco-303": {
      "title": "Aalco: Stainless Steel Grade 303 / 1.4305 data sheet (PDF hosted by Farnell)",
      "id": "26031.pdf",
      "url": "https://www.farnell.com/datasheets/26031.pdf",
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "usgs-nickel-2026": {
      "title": "USGS Mineral Commodity Summaries 2026: Nickel",
      "id": "mcs2026-nickel",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain"
    },
    "usgs-chromium-2026": {
      "title": "USGS Mineral Commodity Summaries 2026: Chromium",
      "id": "mcs2026-chromium",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain"
    },
    "pubchem-nickel": {
      "title": "PubChem: Nickel (CID 935), UN GHS classification",
      "id": "CID 935",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/935/JSON",
      "kind": "database",
      "license": "PubChem terms (public)"
    },
    "pubchem-chromium": {
      "title": "PubChem: Chromium (CID 23976), UN GHS classification",
      "id": "CID 23976",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON",
      "kind": "database",
      "license": "PubChem terms (public)"
    },
    "pubchem-manganese": {
      "title": "PubChem: Manganese (CID 23930), UN GHS classification",
      "id": "CID 23930",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23930/JSON",
      "kind": "database",
      "license": "PubChem terms (public)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/stainless-303/"
}