{
  "spore": "profile",
  "id": "tool-steel-p20",
  "spore_version": "0.2",
  "family": "tool-steels",
  "name": "P20 plastic mould steel (AISI P20, UNS T51620, EN 1.2311)",
  "abbreviation": "P20 (UNS T51620)",
  "role": "plastic mould steel",
  "category": "metals",
  "type": "steels-and-stainless",
  "summary": "P20 is a pre-hardened chromium-molybdenum mould steel (UNS T51620; EN 1.2311) supplied at about 280 to 325 HB, so mould blocks can be machined and used without a further heat treatment. It machines and polishes well and is used for plastic moulds, mould frames and zinc die-casting dies. It is not corrosion resistant and rusts unless it is protected.",
  "best_for": "Plastic injection-mould blocks, mould frames and bolsters that are machined in the pre-hardened condition and then polished (Smith Metal Centres; Oberste-Beulmann; Abrams).",
  "weakest_at": "Corrosion resistance. The datasheets say it is not corrosion resistant and rusts unless protected; Aços Formosa points PVC and gas-releasing plastics to the stainless grade 1.2316 instead.",
  "identity": {
    "formula": "Fe balance; 0.28 to 0.40 C, 0.60 to 1.00 Mn, 0.20 to 0.80 Si, 1.40 to 2.00 Cr, 0.30 to 0.55 Mo, 0.25 max Cu, 0.03 max P, 0.03 max S (wt%, P20 limits as printed by Smith Metal Centres). The EN grade 1.2311 (40CrMnMo7) prints 0.35 to 0.45 C, 0.2 to 0.4 Si, 1.3 to 1.6 Mn, 1.8 to 2.1 Cr and 0.15 to 0.25 Mo (Abrams).",
    "designations": [
      {
        "system": "AISI / SAE",
        "code": "P20",
        "source": "smith-p20",
        "where": "Title block, P20 (T51620)"
      },
      {
        "system": "AISI",
        "code": "P-20",
        "source": "alro-p20",
        "where": "Heading AISI P-20 Steel"
      },
      {
        "system": "Trade name",
        "code": "P-20",
        "source": "formosa-p20",
        "where": "Plastic Molds, P-20 family"
      },
      {
        "system": "UNS",
        "code": "T51620",
        "source": "tm-p20",
        "where": "Page heading and chemical composition table"
      },
      {
        "system": "ASTM",
        "code": "A 681 Type P20",
        "source": "tm-p20",
        "where": "International Equivalent Materials table, row A 681 Type P20 (listed as Official)"
      },
      {
        "system": "EN",
        "code": "1.2311",
        "source": "beul-2311",
        "where": "Header, grade 1.2311+QT"
      },
      {
        "system": "EN name",
        "code": "40CrMnMo7",
        "source": "sij-2311",
        "where": "Designation by Standards table, DIN column"
      },
      {
        "system": "ISO",
        "code": "4957",
        "source": "doer-2738",
        "where": "Opening paragraph, listing 1.2311 (AISI P20) under DIN EN ISO 4957"
      },
      {
        "system": "AFNOR",
        "code": "35CMD7",
        "source": "beul-2311",
        "where": "Standards column, AFNOR row"
      },
      {
        "system": "AFNOR",
        "code": "40CMD8",
        "note": "Oberste-Beulmann prints 35CMD7 for the same EN grade",
        "source": "swiss-2311",
        "where": "Header, AISI P20 / AFNOR 40CMD8"
      },
      {
        "system": "GOST",
        "code": "40ХГМА",
        "source": "beul-2311",
        "where": "Standards column, GOST row"
      },
      {
        "system": "Trade name",
        "code": "SIMOLD 2311",
        "source": "sij-2311",
        "where": "Header, SIMOLD 2311 Steel"
      },
      {
        "system": "Trade name",
        "code": "PREMIUM 1.2311",
        "source": "abrams-12311",
        "where": "Page title, PREMIUM 1.2311 Steel"
      },
      {
        "system": "Trade name",
        "code": "THYROPLAST 2311",
        "source": "tm-p20",
        "where": "International Equivalent Materials table, proprietary row (listed as Official)"
      }
    ],
    "source": "smith-p20",
    "where": "Chemical Composition (weight %), Min and Max rows"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "mechanisms",
      "structures"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, average value",
      "value": 7.83,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "condition": "pre-hardened plastic mould steel, average value as printed",
        "temperature": "ambient, as printed",
        "heat_treatment": "not stated for density"
      },
      "method": "Physical properties table, average values at ambient temperature, as printed",
      "status": "ground",
      "source": "sij-2311",
      "where": "Physical properties, Density (g/cm3), 7.83",
      "source_detail": {
        "title": "SIJ Metal Ravne: SIMOLD 2311 (1.2311) datasheet",
        "id": "SIMOLD 2311, 1.2311, approx. P20",
        "url": "https://cms.sij.si/storage/190/SIMOLD-2311_Metal.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, specific gravity",
      "value": 7.86,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "temperature": "not stated",
        "heat_treatment": "not stated",
        "unit_in_source": "kg/m3 (7861 kg/m3 printed beside 0.284 lb/in3)"
      },
      "method": "Properties block as printed (Specific Gravity 7.86)",
      "status": "ground",
      "source": "alro-p20",
      "where": "Properties block, Density and Specific Gravity rows",
      "source_detail": {
        "title": "Alro Steel: P-20 tool steel grade information",
        "id": "AISI P-20",
        "url": "https://www.myalro.com/gradeinfo/Metals_Gridpt.aspx?gp=0335",
        "kind": "web",
        "license": "supplier web page, cited not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, average value",
      "value": 210,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "condition": "average value at ambient temperature, as printed",
        "heat_treatment": "not stated",
        "unit_in_source": "10^3 x N/mm2 (equal to GPa)"
      },
      "method": "Physical properties table as printed; the datasheet says its values are typical or average, not guaranteed",
      "status": "ground",
      "source": "sij-2311",
      "where": "Physical properties, Modulus of elasticity, row 210",
      "source_detail": {
        "title": "SIJ Metal Ravne: SIMOLD 2311 (1.2311) datasheet",
        "id": "SIMOLD 2311, 1.2311, approx. P20",
        "url": "https://cms.sij.si/storage/190/SIMOLD-2311_Metal.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Elastic modulus, typical",
      "value": 190,
      "value_high": 210,
      "bound": "range",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "condition": "pre-hardened P20, typical values (about 300 HB, 30 HRC as printed)"
      },
      "method": "Mechanical properties (typical) table as printed",
      "status": "ground",
      "source": "smith-p20",
      "where": "Mechanical Properties (typical) table, Elastic Modulus column",
      "source_detail": {
        "title": "Smith Metal Centres: P20 (T51620) product datasheet",
        "id": "P20 (T51620)",
        "url": "https://www.smithmetal.com/pdf/tool-steel/p20.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, 0 to 30 C",
      "value": 190,
      "value_high": 210,
      "bound": "range",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "0 to 30 C (as printed)",
        "heat_treatment": "not stated"
      },
      "method": "UNS T51620 physical properties table, range as printed",
      "status": "ground",
      "source": "tm-p20",
      "where": "UNS T51620 Physical Properties, Modulus of Elasticity row",
      "source_detail": {
        "title": "TotalMateria: UNS T51620 (P20) material page, chemical composition, physical properties and equivalents",
        "id": "UNS T51620",
        "url": "https://www.totalmateria.com/en-us/material/1241786",
        "kind": "database",
        "license": "database page, cited not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, typical",
      "value": 207,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "not stated",
        "heat_treatment": "not stated",
        "unit_in_source": "30 x 10^6 psi (printed with 207 GPa)"
      },
      "method": "Properties block as printed",
      "status": "ground",
      "source": "alro-p20",
      "where": "Properties block, Modulus of Elasticity row",
      "source_detail": {
        "title": "Alro Steel: P-20 tool steel grade information",
        "id": "AISI P-20",
        "url": "https://www.myalro.com/gradeinfo/Metals_Gridpt.aspx?gp=0335",
        "kind": "web",
        "license": "supplier web page, cited not reproduced"
      }
    },
    {
      "benchmark": "poissons_ratio",
      "label": "Poisson's ratio, 0 to 30 C",
      "value": 0.27,
      "value_high": 0.3,
      "bound": "range",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "temperature": "0 to 30 C (as printed)",
        "heat_treatment": "not stated"
      },
      "method": "UNS T51620 physical properties table, range as printed",
      "status": "ground",
      "source": "tm-p20",
      "where": "UNS T51620 Physical Properties, Poisson Coefficient row",
      "source_detail": {
        "title": "TotalMateria: UNS T51620 (P20) material page, chemical composition, physical properties and equivalents",
        "id": "UNS T51620",
        "url": "https://www.totalmateria.com/en-us/material/1241786",
        "kind": "database",
        "license": "database page, cited not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength, typical",
      "value": 827,
      "value_high": 862,
      "bound": "range",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "condition": "pre-hardened P20, typical (about 300 HB, 30 HRC as printed)",
        "test": "tensile, method not stated on the datasheet"
      },
      "method": "Mechanical properties (typical) table as printed, Yield column",
      "status": "ground",
      "source": "smith-p20",
      "where": "Mechanical Properties (typical) table, Tensile Strength Yield row",
      "source_detail": {
        "title": "Smith Metal Centres: P20 (T51620) product datasheet",
        "id": "P20 (T51620)",
        "url": "https://www.smithmetal.com/pdf/tool-steel/p20.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, typical",
      "value": 965,
      "value_high": 1030,
      "bound": "range",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "condition": "pre-hardened P20, typical (about 300 HB, 30 HRC as printed)",
        "test": "tensile, method not stated on the datasheet"
      },
      "method": "Mechanical properties (typical) table as printed, Ultimate column",
      "status": "ground",
      "source": "smith-p20",
      "where": "Mechanical Properties (typical) table, Tensile Strength Ultimate row",
      "source_detail": {
        "title": "Smith Metal Centres: P20 (T51620) product datasheet",
        "id": "P20 (T51620)",
        "url": "https://www.smithmetal.com/pdf/tool-steel/p20.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, converted from hardness",
      "value": 950,
      "value_high": 1100,
      "bound": "range",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "condition": "supplied quenched and tempered, 280 to 325 HB as delivered",
        "unit_in_source": "N/mm2"
      },
      "method": "Converted from hardness by the datasheet (DIN EN ISO 18265 Tab. A.1), not a tensile test; kept as calculated",
      "status": "calculated",
      "source": "beul-2311",
      "where": "Header table, Tensile strength (N/mm2), 950 - 1100",
      "source_detail": {
        "title": "Wilhelm Oberste-Beulmann: 1.2311+QT (40CrMnMo7) technical data sheet",
        "id": "1.2311+QT, code 40CrMnMo7",
        "url": "https://www.oberste-beulmann.de/Dateien/Datenblaetter/1.2311.qt.en.pdf",
        "year": 2018,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation at break, typical",
      "value": 20,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "condition": "pre-hardened P20, typical (about 300 HB, 30 HRC as printed)",
        "gauge": "50 mm (2 in.) as printed"
      },
      "method": "Mechanical properties (typical) table as printed",
      "status": "ground",
      "source": "smith-p20",
      "where": "Mechanical Properties (typical) table, Elongation at break in 50 mm row",
      "source_detail": {
        "title": "Smith Metal Centres: P20 (T51620) product datasheet",
        "id": "P20 (T51620)",
        "url": "https://www.smithmetal.com/pdf/tool-steel/p20.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_brinell",
      "label": "Hardness as delivered",
      "value": 280,
      "value_high": 325,
      "bound": "range",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "condition": "supplied quenched and tempered (pre-hardened, as delivered)",
        "scale": "HB"
      },
      "method": "Header table, Hardness (HB) row, as printed",
      "status": "ground",
      "source": "beul-2311",
      "where": "Header table, Hardness (HB) row, 280 - 325",
      "source_detail": {
        "title": "Wilhelm Oberste-Beulmann: 1.2311+QT (40CrMnMo7) technical data sheet",
        "id": "1.2311+QT, code 40CrMnMo7",
        "url": "https://www.oberste-beulmann.de/Dateien/Datenblaetter/1.2311.qt.en.pdf",
        "year": 2018,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_brinell",
      "label": "Hardness as delivered",
      "value": 280,
      "value_high": 325,
      "bound": "range",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "condition": "as-delivered pre-hardened condition",
        "scale": "HB"
      },
      "method": "Material Properties list as printed, hardness in as-delivered condition",
      "status": "ground",
      "source": "swiss-2311",
      "where": "Material Properties, Hardness in as-delivered condition 280 to 325 HB",
      "source_detail": {
        "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
        "id": "Formadur 2311, AISI P20 / AFNOR 40CMD8",
        "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_brinell",
      "label": "Hardness, typical",
      "value": 300,
      "bound": "exact",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "condition": "pre-hardened P20, typical values",
        "scale": "HB"
      },
      "method": "Mechanical properties (typical) table as printed, Brinell column",
      "status": "ground",
      "source": "smith-p20",
      "where": "Mechanical Properties (typical) table, Hardness Brinell 300",
      "source_detail": {
        "title": "Smith Metal Centres: P20 (T51620) product datasheet",
        "id": "P20 (T51620)",
        "url": "https://www.smithmetal.com/pdf/tool-steel/p20.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_brinell",
      "label": "Hardness after soft annealing, maximum",
      "value": 230,
      "bound": "upper",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "condition": "soft annealed at 710 to 740 C, cooled slowly in the furnace",
        "scale": "HB"
      },
      "method": "Soft Annealing paragraph as printed (maximum Brinell hardness of 230)",
      "status": "ground",
      "source": "sij-2311",
      "where": "Soft Annealing paragraph",
      "source_detail": {
        "title": "SIJ Metal Ravne: SIMOLD 2311 (1.2311) datasheet",
        "id": "SIMOLD 2311, 1.2311, approx. P20",
        "url": "https://cms.sij.si/storage/190/SIMOLD-2311_Metal.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness, typical",
      "value": 30,
      "bound": "exact",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "condition": "pre-hardened P20, typical values (about 300 HB as printed)",
        "scale": "HRC"
      },
      "method": "Mechanical properties (typical) table as printed, Rockwell column",
      "status": "ground",
      "source": "smith-p20",
      "where": "Mechanical Properties (typical) table, Hardness Rockwell 30",
      "source_detail": {
        "title": "Smith Metal Centres: P20 (T51620) product datasheet",
        "id": "P20 (T51620)",
        "url": "https://www.smithmetal.com/pdf/tool-steel/p20.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness, prehardened supply",
      "value": 30,
      "value_high": 34,
      "bound": "range",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "condition": "prehardened, supplied condition for the P-20 family (approximately, as printed)",
        "scale": "HRC"
      },
      "method": "Products and Applications text as printed, approximately 30 to 34 HRC",
      "status": "ground",
      "source": "formosa-p20",
      "where": "Introduction paragraph and P-20 Standard row (Prehardened 30-34 HRC)",
      "source_detail": {
        "title": "Aços Formosa: Plastic mold steels (P-20 family, 1.2311, 1.2312, 1.2738, 1.2316)",
        "id": "P-20 family",
        "url": "https://acosformosa.com.br/en/products/plastic-mold-steels/",
        "year": 2026,
        "kind": "web",
        "license": "supplier web page, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness, pre-hardened (vendor statement)",
      "value": 28,
      "value_high": 34,
      "bound": "range",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "condition": "pre-hardened, as supplied (vendor statement, no test conditions)",
        "scale": "HRC"
      },
      "method": "Vendor comparison page, In-depth Analysis paragraph, as printed; a vendor statement, not a datasheet value",
      "status": "ground",
      "note": "vendor statement; the datasheets read give 30 to 34 HRC or 280 to 325 HB",
      "source": "boxu-s136",
      "where": "In-depth Analysis paragraph, first sentence on P20",
      "source_detail": {
        "title": "Taizhou Boxumold: P20 vs S136 mold steel comparison (vendor article)",
        "id": "vendor comparison",
        "url": "https://www.boxumold.com/en/comparisons/p20-vs-s136-mold-steel",
        "year": 2026,
        "kind": "web",
        "license": "vendor page, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Working hardness, delivery condition",
      "value": 32,
      "bound": "exact",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "condition": "delivery condition (pre-hardened)",
        "scale": "HRC"
      },
      "method": "Standard values table as printed, approx. 32 HRC in the delivery condition",
      "status": "ground",
      "source": "abrams-12311",
      "where": "Standard values table, Working hardness row",
      "source_detail": {
        "title": "Abrams Industries: PREMIUM 1.2311 steel, standard values (text derived from stahlwissen.de)",
        "id": "PREMIUM 1.2311",
        "url": "https://eu.abrams-industries.com/steel/premium-12311",
        "kind": "web",
        "license": "supplier web page, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness after quenching",
      "value": 51,
      "bound": "exact",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "condition": "after hardening at 840 to 870 C with oil or salt-bath quench at 180 to 220 C (re-hardened, not the supplied condition)",
        "scale": "HRC"
      },
      "method": "Heat treatment table, Hardening row, as printed (51 HRC after quenching)",
      "status": "ground",
      "source": "swiss-2311",
      "where": "Heat treatment table, Hardening row",
      "source_detail": {
        "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
        "id": "Formadur 2311, AISI P20 / AFNOR 40CMD8",
        "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness after tempering at 500 C",
      "value": 42,
      "bound": "exact",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "condition": "after hardening, tempered at 500 C (tempering chart; hold time not printed)",
        "scale": "HRC"
      },
      "method": "Tempering chart as printed",
      "status": "ground",
      "source": "swiss-2311",
      "where": "Heat treatment, Tempering chart, 500 C row",
      "source_detail": {
        "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
        "id": "Formadur 2311, AISI P20 / AFNOR 40CMD8",
        "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness after tempering at 600 C",
      "value": 36,
      "bound": "exact",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "condition": "after hardening, tempered at 600 C (tempering chart; hold time not printed)",
        "scale": "HRC"
      },
      "method": "Tempering chart as printed",
      "status": "ground",
      "source": "swiss-2311",
      "where": "Heat treatment, Tempering chart, 600 C row",
      "source_detail": {
        "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
        "id": "Formadur 2311, AISI P20 / AFNOR 40CMD8",
        "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness after tempering at 700 C",
      "value": 28,
      "bound": "exact",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "condition": "after hardening, tempered at 700 C (tempering chart; hold time not printed)",
        "scale": "HRC"
      },
      "method": "Tempering chart as printed",
      "status": "ground",
      "source": "swiss-2311",
      "where": "Heat treatment, Tempering chart, 700 C row",
      "source_detail": {
        "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
        "id": "Formadur 2311, AISI P20 / AFNOR 40CMD8",
        "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, quenched and tempered",
      "value": 32.5,
      "bound": "exact",
      "unit": "W/m.K",
      "scope": "material",
      "conditions": {
        "condition": "quenched and tempered",
        "temperature": "23 C"
      },
      "method": "Physical properties table, Thermal conductivity, quenched and tempered column, as printed",
      "status": "ground",
      "source": "swiss-2311",
      "where": "Physical properties, Thermal conductivity (W/m.K), quenched and tempered, 23 C",
      "source_detail": {
        "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
        "id": "Formadur 2311, AISI P20 / AFNOR 40CMD8",
        "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, quenched and tempered",
      "value": 34,
      "bound": "exact",
      "unit": "W/m.K",
      "scope": "material",
      "conditions": {
        "condition": "quenched and tempered",
        "temperature": "100 C"
      },
      "method": "Physical properties paragraph as printed, average values",
      "status": "ground",
      "source": "sij-2311",
      "where": "Physical properties, Thermal conductivity, 34.0 at 100 C, quenched and tempered",
      "source_detail": {
        "title": "SIJ Metal Ravne: SIMOLD 2311 (1.2311) datasheet",
        "id": "SIMOLD 2311, 1.2311, approx. P20",
        "url": "https://cms.sij.si/storage/190/SIMOLD-2311_Metal.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, 20 to 100 C",
      "value": 12.6,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "condition": "quenched and tempered",
        "temperature": "20 to 100 C",
        "unit_in_source": "10^-6 K^-1 (same number as ppm/K)"
      },
      "method": "Physical properties table, coefficient of thermal expansion row, as printed",
      "status": "ground",
      "source": "swiss-2311",
      "where": "Physical properties, coefficient of thermal expansion, 20 to 100 C, quenched and tempered",
      "source_detail": {
        "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
        "id": "Formadur 2311, AISI P20 / AFNOR 40CMD8",
        "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, 20 to 500 C",
      "value": 14.3,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "condition": "quenched and tempered",
        "temperature": "20 to 500 C",
        "unit_in_source": "10^-6 K^-1 (same number as ppm/K)"
      },
      "method": "Physical properties table, coefficient of thermal expansion row, as printed",
      "status": "ground",
      "source": "swiss-2311",
      "where": "Physical properties, coefficient of thermal expansion, 20 to 500 C, quenched and tempered",
      "source_detail": {
        "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
        "id": "Formadur 2311, AISI P20 / AFNOR 40CMD8",
        "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, 20 to 100 C",
      "value": 11.7,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "temperature": "20 to 100 C",
        "heat_treatment": "not stated",
        "unit_in_source": "10^-6 C^-1 (same number as ppm/K)"
      },
      "method": "Physical properties table as printed, average values at ambient temperature",
      "status": "ground",
      "source": "sij-2311",
      "where": "Physical properties, coefficient of thermal expansion, 20-100 C row",
      "source_detail": {
        "title": "SIJ Metal Ravne: SIMOLD 2311 (1.2311) datasheet",
        "id": "SIMOLD 2311, 1.2311, approx. P20",
        "url": "https://cms.sij.si/storage/190/SIMOLD-2311_Metal.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    },
    {
      "benchmark": "machinability_relative",
      "label": "Machinability relative to a 1% carbon steel",
      "value": 60,
      "value_high": 65,
      "bound": "range",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "reference": "1% carbon steel, as printed",
        "heat_treatment": "not stated"
      },
      "method": "Properties block, Machinability row, as printed",
      "status": "ground",
      "source": "alro-p20",
      "where": "Properties block, Machinability row, 60-65% of a 1% carbon steel",
      "source_detail": {
        "title": "Alro Steel: P-20 tool steel grade information",
        "id": "AISI P-20",
        "url": "https://www.myalro.com/gradeinfo/Metals_Gridpt.aspx?gp=0335",
        "kind": "web",
        "license": "supplier web page, cited not reproduced"
      }
    },
    {
      "benchmark": "machinability_relative",
      "label": "Machinability relative to W-group water-hardening steel",
      "value": 80,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "reference": "W group water-hardening steels, as printed",
        "basis": "printed as about 80%"
      },
      "method": "Machinability paragraph as printed",
      "status": "ground",
      "note": "approximate, printed as about 80%",
      "source": "sij-2311",
      "where": "Machinability paragraph",
      "source_detail": {
        "title": "SIJ Metal Ravne: SIMOLD 2311 (1.2311) datasheet",
        "id": "SIMOLD 2311, 1.2311, approx. P20",
        "url": "https://cms.sij.si/storage/190/SIMOLD-2311_Metal.pdf",
        "year": 2016,
        "kind": "datasheet",
        "license": "supplier datasheet, cited not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Humid or wet storage, or service with no surface protection",
      "headline": "The datasheet says the alloy will corrode or rust unless protected.",
      "effect": "Simold 2311 states: 'This is a steel alloy and it will corrode or rust unless protected.' No exposure time, humidity or test is given. The low rating is an assistant judgement from this wording, not a test result.",
      "rating": "low",
      "conditions": {
        "basis": "datasheet statement",
        "test": "none printed"
      },
      "source": "sij-2311",
      "where": "Corrosion Resistance paragraph"
    },
    {
      "environment": "Storage and use in damp or wet conditions (EN 1.2311)",
      "headline": "Abrams says 1.2311 is not a corrosion resistant steel.",
      "effect": "Abrams says 1.2311 is not a corrosion resistant steel and that surface treatment, maintenance and dry storage of parts can extend corrosion resistance but cannot completely prevent rusting. Bluing gives a black oxide layer with some corrosion protection, though it is usually done for appearance. The low rating is an assistant judgement from this wording.",
      "rating": "low",
      "conditions": {
        "basis": "datasheet statement for the EN grade",
        "test": "none printed"
      },
      "source": "abrams-12311",
      "where": "Is the 1.2311 corrosion resistant? answer; Black oxide coating or blueing section"
    },
    {
      "environment": "Humid conditions with no protection (vendor comparison)",
      "headline": "A vendor says P20 has no corrosion resistance.",
      "effect": "The Boxumold comparison says P20 has no corrosion resistance and rusts in humid conditions without protection. It is a vendor statement with no test conditions. The low rating is an assistant judgement.",
      "rating": "low",
      "conditions": {
        "basis": "vendor statement",
        "test": "none printed"
      },
      "source": "boxu-s136",
      "where": "Side-by-Side Comparison table, Corrosion Resistance row"
    },
    {
      "environment": "PVC and plastics that release aggressive gases during moulding",
      "headline": "Aços Formosa points these plastics to stainless grades, not to P20.",
      "effect": "Aços Formosa points PVC and gas-releasing plastics to 420-series stainless steels and to the prehardened stainless grade 1.2316, not to P20. It gives no corrosion test for P20 itself.",
      "rating": "unknown",
      "conditions": {
        "basis": "supplier product guidance",
        "test": "none printed for P20"
      },
      "source": "formosa-p20",
      "where": "Best Choice for Stainless Steels for Molds list and Applications list"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem's aggregated GHS record for elemental chromium carries the signal word Danger. 50% of 2404 company reports (1202) say it does not meet GHS criteria. Reported codes include H317, may cause an allergic skin reaction (20.7% of reports), and H400, very toxic to aquatic life. The record describes the element, not the steel.",
        "ghs": [
          "H317",
          "H400"
        ],
        "source": "pubchem-cr",
        "where": "Safety and Hazards, GHS Classification (CID 23976)"
      },
      {
        "text": "PubChem's aggregated GHS record for elemental manganese: 46.1% (1429 of 3101) of reports say it does not meet GHS criteria. Reported codes include H228, flammable solid (11.6% of reports), H360, may damage fertility or the unborn child, and H372, damage to organs through prolonged or repeated exposure. The record describes the element, not the steel.",
        "ghs": [
          "H228",
          "H360",
          "H372"
        ],
        "source": "pubchem-mn",
        "where": "Safety and Hazards, GHS Classification (CID 23930)"
      },
      {
        "text": "PubChem's aggregated GHS record for elemental molybdenum: 57.4% (874 of 1523) of reports say it does not meet GHS criteria. Reported codes include H225 (11.6% of reports), H315, skin irritation, and H335, may cause respiratory irritation. The record describes the element, not the steel.",
        "ghs": [
          "H225",
          "H315",
          "H335"
        ],
        "source": "pubchem-mo",
        "where": "Safety and Hazards, GHS Classification (CID 23932)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Softening when a weld or reheat goes above 565 C",
        "trigger": "Weld repair or reheating above 565 C; the datasheet gives 540 C for weld tempering",
        "consequence": "Hardness is lost if the material is heated above 565 C during welding (Abrams).",
        "severity": "moderate",
        "source": "abrams-12311",
        "where": "Welding section"
      },
      {
        "mode": "Softening on reheating to a higher temper",
        "trigger": "Reheating or stress relief at 600 C or 700 C",
        "consequence": "The Swiss Steel tempering chart gives 42 HRC after tempering at 500 C, 36 HRC at 600 C and 28 HRC at 700 C; a reheat above the supply temper softens the block.",
        "severity": "moderate",
        "source": "swiss-2311",
        "where": "Heat treatment, Tempering chart"
      },
      {
        "mode": "Stress corrosion cracking after oil hardening",
        "trigger": "Oil hardening without interruption at 300 to 400 C, or cooling to room temperature before tempering",
        "consequence": "The datasheet warns of enhanced stress corrosion cracking susceptibility after oil hardening, and says to temper while the part is at about 80 C.",
        "severity": "moderate",
        "source": "beul-2311",
        "where": "Heat treatment table, Quenching remarks"
      },
      {
        "mode": "Thick blocks harden less through",
        "trigger": "Sections thicker than 400 mm",
        "consequence": "The Oberste-Beulmann datasheet recommends 1.2738 for thicknesses above 400 mm because of its better through-hardenability.",
        "severity": "moderate",
        "source": "beul-2311",
        "where": "Header table, Remarks"
      },
      {
        "mode": "Rust in humid storage or service",
        "trigger": "Storage or service in humid conditions without surface protection",
        "consequence": "The steel rusts; the Simold datasheet says it will corrode or rust unless protected.",
        "severity": "moderate",
        "source": "sij-2311",
        "where": "Corrosion Resistance paragraph"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Preheating before use at 200 to 300 C is recommended by the datasheet.",
        "source": "beul-2311",
        "where": "Header table, Remarks (preheating before use)"
      },
      {
        "text": "Hot forming between 1050 and 850 C (as printed for forging).",
        "source": "sij-2311",
        "where": "Forging paragraph"
      },
      {
        "text": "Soft anneal at 710 to 740 C in the furnace, cooling slowly; the Simold datasheet gives a maximum of 230 HB afterwards.",
        "source": "sij-2311",
        "where": "Soft Annealing paragraph"
      },
      {
        "text": "Stress relieve at 500 to 550 C in the quenched and tempered condition, then cool in the furnace (Oberste-Beulmann). Abrams gives 550 to 600 C for 1 hour per 25 mm.",
        "source": "beul-2311",
        "where": "Heat treatment table, Stress-relief annealing row"
      },
      {
        "text": "Stress relieve at 550 to 600 C for 1 hour per 25 mm of thickness, then cool in the furnace (Abrams).",
        "source": "abrams-12311",
        "where": "1.2311 Stress relieving section"
      },
      {
        "text": "Temper by holding at the tempering temperature for at least 1 hour per 25 mm of section, then cool in still air (Smith Metal Centres).",
        "source": "smith-p20",
        "where": "Tempering paragraph"
      },
      {
        "text": "Re-harden from 830 to 880 C, then quench in oil or a warm bath at 180 to 220 C; the hardness after quenching is 51 HRC (Simold).",
        "source": "sij-2311",
        "where": "Hardening paragraph"
      },
      {
        "text": "Weld with a preheat of 315 to 370 C, do not let the temperature fall below 315 C, cool slowly to 40 to 65 C, reheat to 540 C for 1 hour per 25 mm of weld depth, and do not exceed 565 C (Abrams).",
        "source": "abrams-12311",
        "where": "1.2311 Welding section"
      }
    ],
    "mitigations": [
      {
        "text": "Surface treatment, maintenance and dry storage can extend corrosion resistance but cannot completely prevent rusting (Abrams).",
        "source": "abrams-12311",
        "where": "Is the 1.2311 corrosion resistant? answer"
      },
      {
        "text": "Nitriding gives a hard, abrasion-resistant surface to a depth of 0.40 mm (Abrams); the surface can be made harder than the pre-hardened core.",
        "source": "abrams-12311",
        "where": "1.2311 Nitriding section, printed as 0,40 mm with a decimal comma"
      },
      {
        "text": "For thick blocks above 400 mm, the Oberste-Beulmann datasheet recommends 1.2738 for better through-hardening.",
        "source": "beul-2311",
        "where": "Header table, Remarks"
      },
      {
        "text": "For PVC and plastics that release aggressive gases, Aços Formosa points to the prehardened stainless grade 1.2316.",
        "source": "formosa-p20",
        "where": "Best Choice list, Stainless Steels for Molds"
      }
    ]
  },
  "uses": [
    {
      "application": "mechanisms",
      "device": "Plastic injection-mould cavities, cores and inserts",
      "example": "Aços Formosa lists cavities and cores among the applications of its P-20 family plastic mould steels.",
      "source": "formosa-p20",
      "where": "Applications list"
    },
    {
      "application": "structures",
      "device": "Mould frames, bolsters and die holders",
      "example": "Smith Metal Centres says P20 is commonly used to make large mould frames and bolsters; Alro lists die holders and bolsters.",
      "source": "smith-p20",
      "where": "Opening paragraph and Typical applications line"
    },
    {
      "application": "mechanisms",
      "device": "Zinc die-casting dies and pressure-casting dies",
      "example": "Smith Metal Centres and Alro list zinc die-casting dies among typical uses, and Simold lists pressure casting dies.",
      "source": "alro-p20",
      "where": "Typical Uses line"
    },
    {
      "application": "mechanisms",
      "device": "Rails and shafts (secondary use of the EN 1.2311 grade)",
      "example": "Abrams says the grade is mainly used for plastic moulds, die casts and tools but is also suitable for applications such as rails and shafts.",
      "source": "abrams-12311",
      "where": "Introduction paragraph"
    }
  ],
  "supply": [
    {
      "subject": "Chromium",
      "abundance": "World resources are greater than 12 billion tons of shipping-grade chromite, 95% of them in Kazakhstan and southern Africa. US net import reliance was 79% of apparent consumption in 2025e (USGS).",
      "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
        },
        {
          "country": "Finland",
          "share_percent": 3.7,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals, read from a fetch summary (the page returned 403 to curl)",
          "listed": true
        },
        {
          "list": "EU critical raw materials list, fifth list 2023 (34 CRMs, European Commission page)",
          "listed": false
        }
      ],
      "recycling": "Recycled chromium in stainless-steel scrap receipts was 21% of US apparent consumption in 2025.",
      "substitutes": [
        "Chromium has no substitute in stainless steel, the leading end use, or in superalloys (USGS 2026)."
      ],
      "source": "usgs-cr-2026",
      "where": "Salient Statistics; World Mine Production and Reserves (2025e; shares calculated by Space Mushroom from printed tonnage over the 51,000 thousand t world total); World Resources; Substitutes; Recycling"
    },
    {
      "subject": "Manganese",
      "abundance": "Land-based manganese resources are large but irregularly distributed; South Africa accounts for an estimated 70% of world resources. US net import reliance was 100% of apparent consumption in each year from 2021 to 2025e (USGS).",
      "producers": [
        {
          "country": "South Africa",
          "share_percent": 38,
          "year": 2025
        },
        {
          "country": "Gabon",
          "share_percent": 25,
          "year": 2025
        },
        {
          "country": "Ghana",
          "share_percent": 10,
          "year": 2025
        },
        {
          "country": "Australia",
          "share_percent": 8,
          "year": 2025
        },
        {
          "country": "Brazil",
          "share_percent": 4,
          "year": 2025
        },
        {
          "country": "India",
          "share_percent": 3.95,
          "year": 2025
        },
        {
          "country": "China",
          "share_percent": 3.5,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals, read from a fetch summary (the page returned 403 to curl)",
          "listed": true
        },
        {
          "list": "EU critical raw materials list, fifth list 2023 (34 CRMs, European Commission page)",
          "listed": true
        }
      ],
      "recycling": "Manganese was recycled incidentally in ferrous and nonferrous scrap, but scrap recovery specifically for manganese was negligible; it is recovered with iron from steel slag (USGS).",
      "substitutes": [
        "Manganese has no satisfactory substitute in its major applications (USGS 2026)."
      ],
      "source": "usgs-mn-2026",
      "where": "Salient Statistics; World Mine Production and Reserves (manganese content, 2025e; shares calculated by Space Mushroom from printed tonnage over the 20,000 thousand t world total); World Resources; Substitutes; Recycling"
    },
    {
      "subject": "Molybdenum",
      "abundance": "Identified resources are about 5.4 million tons in the United States and about 20 million tons in the rest of the world; world reserves were 17,000 thousand t (2025e). Molybdenum is used principally as an alloying agent in steels, cast irons and superalloys (USGS 2026).",
      "producers": [
        {
          "country": "China",
          "share_percent": 37.3,
          "year": 2025
        },
        {
          "country": "Chile",
          "share_percent": 16.2,
          "year": 2025
        },
        {
          "country": "United States",
          "share_percent": 15.4,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 15,
          "year": 2025
        },
        {
          "country": "Mexico",
          "share_percent": 6.5,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals, read from a fetch summary (no molybdenum entry)",
          "listed": false
        },
        {
          "list": "EU critical raw materials list, fifth list 2023 (34 CRMs, European Commission page)",
          "listed": false
        }
      ],
      "recycling": "Molybdenum is recycled as a component of catalysts, ferrous scrap and superalloy scrap; recycled material may be as much as 30% of the apparent supply (USGS 2026).",
      "substitutes": [
        "There is little substitution for molybdenum in steels and cast irons; potential substitutes in alloy steels include boron, chromium, niobium and vanadium (USGS 2026)."
      ],
      "source": "usgs-mo-2026",
      "where": "Salient Statistics and Events, Trends and Issues (China export controls, February 2025); World Mine Production and Reserves (2025e; shares calculated by Space Mushroom over the 260,000 thousand t world total); Substitutes; Recycling"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Smith Metal Centres: P20 (T51620) product datasheet",
      "type": "datasheet",
      "url": "https://www.smithmetal.com/pdf/tool-steel/p20.pdf",
      "year": 2023
    },
    {
      "title": "Wilhelm Oberste-Beulmann: 1.2311+QT (40CrMnMo7) technical data sheet",
      "type": "datasheet",
      "url": "https://www.oberste-beulmann.de/Dateien/Datenblaetter/1.2311.qt.en.pdf",
      "year": 2018
    },
    {
      "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
      "type": "datasheet",
      "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
      "year": 2026
    },
    {
      "title": "SIJ Metal Ravne: SIMOLD 2311 (1.2311) datasheet",
      "type": "datasheet",
      "url": "https://cms.sij.si/storage/190/SIMOLD-2311_Metal.pdf",
      "year": 2016
    },
    {
      "title": "Abrams Industries: PREMIUM 1.2311 steel, standard values",
      "type": "datasheet",
      "url": "https://eu.abrams-industries.com/steel/premium-12311"
    },
    {
      "title": "Alro Steel: P-20 tool steel grade information",
      "type": "datasheet",
      "url": "https://www.myalro.com/gradeinfo/Metals_Gridpt.aspx?gp=0335"
    },
    {
      "title": "Aços Formosa: Plastic mold steels (P-20 family)",
      "type": "datasheet",
      "url": "https://acosformosa.com.br/en/products/plastic-mold-steels/",
      "year": 2026
    },
    {
      "title": "TotalMateria: UNS T51620 (P20) material page",
      "type": "database",
      "url": "https://www.totalmateria.com/en-us/material/1241786"
    },
    {
      "title": "Taizhou Boxumold: P20 vs S136 mold steel comparison (vendor article)",
      "type": "report",
      "url": "https://www.boxumold.com/en/comparisons/p20-vs-s136-mold-steel",
      "year": 2026
    },
    {
      "title": "Dörrenberg: 1.2738 (P20+Ni) datasheet",
      "type": "datasheet",
      "url": "https://doerrenberg.de/fileadmin/special_steel/files/pdf_en_products_neues_Design/1.2738_en.pdf"
    },
    {
      "title": "Industeel (ArcelorMittal): DS Mold 2738 (1.2738) datasheet",
      "type": "datasheet",
      "url": "https://industeel.arcelormittal.com/fichier/ds-mold-2738"
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Chromium",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Manganese",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-manganese.pdf",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Molybdenum",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf",
      "year": 2026
    },
    {
      "title": "USGS: About the 2025 List of Critical Minerals",
      "type": "report",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025
    },
    {
      "title": "European Commission: Critical raw materials (fifth list 2023, 34 CRMs)",
      "type": "report",
      "url": "https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en",
      "year": 2023
    },
    {
      "title": "PubChem: Chromium (CID 23976), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON/?heading=GHS+Classification",
      "year": 2026
    },
    {
      "title": "PubChem: Manganese (CID 23930), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23930/JSON/?heading=GHS+Classification",
      "year": 2026
    },
    {
      "title": "PubChem: Molybdenum (CID 23932), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23932/JSON/?heading=GHS+Classification",
      "year": 2026
    }
  ],
  "gaps": [
    "No safety data sheet for P20 steel was read in this run. The hazard entries are PubChem records for the pure elements chromium, manganese and molybdenum, which do not describe the steel.",
    "Hardness as delivered is printed differently by each source: 280 to 325 HB (Oberste-Beulmann, Swiss Steel), about 300 HB and 30 HRC typical (Smith Metal Centres), 30 to 34 HRC (Aços Formosa), about 32 HRC (Abrams) and 28 to 34 HRC (Boxumold, a vendor). None of the pages read in this run printed 28 to 32 HRC for P20 itself, so the about 28 to 32 HRC figure in the brief is not confirmed here.",
    "Composition: the P20 ranges (Smith Metal Centres, TotalMateria) and the EN 1.2311 ranges (Abrams) differ, and the typical values in the 1.2311 datasheets (Simold, Swiss Steel) differ again. The recipe uses the P20 ranges.",
    "Nickel: the Smith Metal Centres text says nickel and chromium enhance hardness and toughness, but its P20 composition table gives no nickel limit, and no P20 table read here lists one.",
    "Soft-annealed hardness conflicts: Simold prints a maximum of 230 HB after soft annealing at 710 to 740 C, while Swiss Steel prints 325 HB or less for the same treatment. Both are kept with their sources; the two were not reconciled.",
    "Stress-relief temperatures differ: 500 to 550 C for the quenched and tempered condition (Oberste-Beulmann), 550 to 600 C for 1 hour per 25 mm (Abrams), and about 650 C for 1 to 2 hours to remove machining stresses (Simold). The Oberste-Beulmann tempering chart gives 32 HRC at 650 C, so the 650 C figure would soften a pre-hardened block; this is an inference, not a printed statement.",
    "Temper hold times differ: at least 1 hour per 25 mm (Smith Metal Centres), at least 2 hours or 1 hour per 25 mm (Abrams), and 1 hour per 20 mm with a minimum of 2 hours (Oberste-Beulmann).",
    "No P20 corrosion test was found in any fetched source. The corrosion entries are datasheet statements and a vendor comparison; no salt, acid or humidity exposure data for P20 were read. A nitriding corrosion study on Impax Supreme (its Gamry abstract calls it equivalent to AISI P20) was fetched but not used, because it is a different steel.",
    "Polishability is described in datasheets and vendor text, not measured: no surface roughness or finish data for P20 were read. The Boxumold SPI B-to-D statement is vendor text and is not used as a value.",
    "Hardness and machinability use snake_case benchmark names (hardness_brinell, hardness_rockwell_c, machinability_relative) because property-canon.yaml has no entry for them.",
    "Critical-mineral status for the USGS 2025 list was read from a WebFetch summary of the USGS page, because curl returned 403 for that page; it is not raw text. The EU status was read from the European Commission page.",
    "Supply shares are calculated by Space Mushroom from the printed USGS tonnage over the printed world totals; they are not printed percentages.",
    "No space, vacuum, radiation or flight use of P20 was found in these sources. The uses are terrestrial moulds, dies and machinery parts.",
    "No Charpy, fracture toughness or fatigue values for P20 were printed in the sources read; the Smith Metal Centres and Alro texts mention toughness without numbers.",
    "No photograph or micrograph of P20 with a licence we could cite was fetched in this run, so media is empty.",
    "Designations: the site's identity schema has no designations field, so identity.designations is likely dropped on import until the schema has that field.",
    "Not reached in this run: ASM Alloy Digest (login required), MakeItFrom (blocked), VEM Tooling and suppliersonline (no readable text), BGH datasheet (blocked), PACE Metallographic (database offline, no P20 values), and the Meusburger 12311 page (navigation only). Dillinger DIMO 2311 is a modified variant and was not read."
  ],
  "story": {
    "why": "P20 (UNS T51620, EN 1.2311) is a chromium-molybdenum mould steel. It is bought pre-hardened at about 280 to 325 HB, so mould blocks can be cut and used without a further heat treatment. Its machinability and polishing are good, and it is used for plastic moulds, mould frames and zinc die-casting dies. Its weak point is corrosion resistance: the datasheets say it rusts unless protected.",
    "uses": [
      {
        "where": "Plastic moulds and frames",
        "line": "Oberste-Beulmann and Swiss Steel list plastic moulds, mould frames and pressure-casting moulds. Smith Metal Centres calls P20 a common steel for large mould frames and bolsters."
      },
      {
        "where": "Zinc die-casting dies",
        "line": "Smith Metal Centres and Alro list zinc die-casting dies among the typical uses."
      },
      {
        "where": "Rails and shafts",
        "line": "Abrams also lists rails and shafts as suitable applications for the EN 1.2311 grade."
      }
    ],
    "can_do": [
      {
        "label": "Hardness",
        "line": "Supplied at 280 to 325 HB (Oberste-Beulmann and Swiss Steel), so blocks can be machined and used without a further heat treatment (Abrams).",
        "scope": "material"
      },
      {
        "label": "Strength",
        "line": "Typical yield strength is 827 to 862 MPa and tensile strength 965 to 1030 MPa in the pre-hardened condition (Smith Metal Centres, typical values).",
        "scope": "material"
      },
      {
        "label": "Stiffness",
        "line": "Modulus of elasticity is 190 to 210 GPa (Smith Metal Centres) and 210 GPa (Simold, average value).",
        "scope": "material"
      },
      {
        "label": "Machining",
        "line": "Machinability is 60 to 65 percent of a 1% carbon steel (Alro), or about 80 percent of W-group water-hardening steel (Simold).",
        "scope": "material"
      },
      {
        "label": "Polish",
        "line": "Polishes to a high gloss, but over-polishing can cause orange peel and pitting (Abrams). Oberste-Beulmann says it is better polishable than the 1.2312 grade.",
        "scope": "material"
      },
      {
        "label": "Weld",
        "line": "Can be welded by conventional methods with preheat and controlled cooling (Abrams). Smith Metal Centres says it has good weldability.",
        "scope": "material"
      },
      {
        "label": "Nitride",
        "line": "Can be nitrided to a case about 0.40 mm deep for a harder, wear-resistant surface (Abrams).",
        "scope": "material"
      }
    ],
    "compare": "P20 sits in a family of pre-hardened plastic mould steels from Aços Formosa: 1.2311 for small and medium moulds, 1.2312 for high machinability, 1.2738 (nickel-added) for large moulds, and P-20 ESR for high-gloss work. For corrosive plastics, Aços Formosa points to the stainless prehardened grade 1.2316 instead. The compare rows give P20's typical strength, stiffness and density.",
    "compare_rows": [
      {
        "label": "Strength",
        "benchmark": "yield_strength",
        "scope": "material"
      },
      {
        "label": "Stiffness",
        "benchmark": "elastic_modulus",
        "scope": "material"
      },
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      }
    ],
    "handling": [
      "Buy and machine it pre-hardened; Abrams says heat treatment is not normally required for the supplied condition.",
      "Keep reheats and welding inside the limits: loss of hardness is the risk above 565 C (Abrams).",
      "Protect it from rust with a surface treatment and dry storage; Abrams says these extend resistance but cannot completely prevent rusting.",
      "Stress relieve at 500 to 550 C for the quenched and tempered condition, then cool in the furnace (Oberste-Beulmann).",
      "Weld only with the preheat and controlled cool-down in the procedure (315 to 370 C preheat, Abrams).",
      "Take a safety data sheet for the specific bar before cutting, grinding or welding; none was read for P20 in this run."
    ],
    "good_for": [
      "Plastic injection-mould blocks and frames machined in the pre-hardened condition (Smith Metal Centres; Oberste-Beulmann).",
      "Zinc and pressure-casting dies, which the datasheets list as typical uses (Smith Metal Centres; Alro).",
      "Textured and polished mould faces; the datasheets say the grade takes texture and polish well (Simold; Abrams)."
    ],
    "watch_out": [
      "Rust: the steel rusts unless it is protected; surface treatment and dry storage extend resistance but cannot completely prevent rusting (Simold; Abrams).",
      "Heat above 565 C during welding or reheating can lose hardness (Abrams); tempering at 600 C leaves 36 HRC (Swiss Steel).",
      "Thick blocks: above 400 mm the Oberste-Beulmann datasheet recommends 1.2738 for better through-hardening.",
      "Corrosive plastics: for PVC and gas-releasing plastics, Aços Formosa points to the stainless 1.2316 instead."
    ],
    "verdict": "P20 is a practical, pre-hardened mould steel. It is supplied at about 280 to 325 HB, machines and polishes well, and suits plastic moulds, mould frames and zinc die-casting dies. It is not corrosion resistant, so protect it from rust, keep reheats within the datasheet limits, and use 1.2738 for thick blocks or a stainless grade for corrosive plastics.",
    "recipe": {
      "line": "P20 is an iron-based chromium-molybdenum tool steel with 0.28 to 0.40 percent carbon. The limits here are the P20 ranges printed by Smith Metal Centres. The EN grade 1.2311 has narrower manganese and chromium ranges (Abrams). Its strength comes from the pre-hardened heat treatment as much as from its composition.",
      "parts": [
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "The matrix of the steel. Heat treatment changes its structure between martensite and tempered martensite.",
          "share_note": "balance (the rest)"
        },
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Sets how hard the steel can become when quenched.",
          "share_percent": 0.28,
          "share_high": 0.4
        },
        {
          "name": "Manganese",
          "symbol": "Mn",
          "role": "Adds hardenability and helps the melt.",
          "share_percent": 0.6,
          "share_high": 1
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Deoxidiser in the melt.",
          "share_percent": 0.2,
          "share_high": 0.8
        },
        {
          "name": "Chromium",
          "symbol": "Cr",
          "role": "Adds hardness and toughness in the alloy (Smith Metal Centres). The grade is not stainless.",
          "share_percent": 1.4,
          "share_high": 2
        },
        {
          "name": "Molybdenum",
          "symbol": "Mo",
          "role": "Adds hardenability. The grade still rusts unless protected.",
          "share_percent": 0.3,
          "share_high": 0.55
        },
        {
          "name": "Copper",
          "symbol": "Cu",
          "role": "Upper limit as printed by Smith Metal Centres; no role is stated in the datasheet.",
          "share_percent": 0,
          "share_high": 0.25
        },
        {
          "name": "Phosphorus",
          "symbol": "P",
          "role": "Impurity, held to a maximum.",
          "share_percent": 0,
          "share_high": 0.03
        },
        {
          "name": "Sulfur",
          "symbol": "S",
          "role": "Impurity, held to a maximum.",
          "share_percent": 0,
          "share_high": 0.03
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The only hazard records found are PubChem entries for the pure elements chromium, manganese and molybdenum. No safety data sheet for P20 bar was read in this run.",
        "points": [
          {
            "label": "Chromium",
            "line": "PubChem lists elemental chromium as Danger. Half of 2404 company reports say it does not meet GHS criteria; H317, allergic skin reaction, appears for 20.7% of reports."
          },
          {
            "label": "Manganese",
            "line": "PubChem lists elemental manganese with H228 (flammable solid, 11.6% of reports), H360 (may damage fertility or the unborn child) and H372 (organ damage on repeated exposure)."
          },
          {
            "label": "Molybdenum",
            "line": "PubChem reports that 57.4% of its reports say elemental molybdenum does not meet GHS criteria; H315 (skin irritation) and H335 (respiratory irritation) appear among the codes."
          }
        ],
        "level": 1,
        "verdict": "No SDS for P20 read; element data only"
      },
      {
        "title": "In service",
        "lead": "The datasheets say the steel is not corrosion resistant, so rust is the main in-service concern.",
        "points": [
          {
            "label": "Rust",
            "line": "The Simold datasheet says the alloy will corrode or rust unless protected. Abrams says surface treatment and dry storage extend resistance but cannot completely prevent rusting."
          },
          {
            "label": "Corrosive plastics",
            "line": "Aços Formosa points PVC and plastics that release aggressive gases to the stainless grade 1.2316, not to P20."
          },
          {
            "label": "Reheating",
            "line": "The Swiss Steel tempering chart shows hardness falling from 42 HRC after tempering at 500 C to 36 HRC at 600 C and 28 HRC at 700 C."
          }
        ],
        "level": 2,
        "verdict": "Rust is the main watch point"
      },
      {
        "title": "Heat treatment and welding",
        "lead": "Heat sets the strength, and the reheat limits matter most.",
        "points": [
          {
            "label": "Welding",
            "line": "Abrams gives a preheat of 315 to 370 C and a limit of 565 C on reheating; above that, hardness can be lost."
          },
          {
            "label": "Stress relief",
            "line": "Oberste-Beulmann gives 500 to 550 C for the quenched and tempered condition; Abrams gives 550 to 600 C."
          },
          {
            "label": "Re-hardening",
            "line": "Re-hardening from 830 to 880 C in oil or a warm bath at 180 to 220 C gives about 51 HRC (Simold)."
          }
        ],
        "level": 1,
        "verdict": "Keep weld and reheat temperatures in check"
      }
    ]
  },
  "updated": "2026-10-24",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 30,
    "unreachable": 0,
    "caveats": 3,
    "note": "Read by an AI assistant on 2026-10-24 from pages fetched in this run. Caveats: the converted tensile value (calculated, not tested), the Boxumold hardness range (a vendor statement), and the about 80 percent machinability figure (approximate). The USGS 2025 critical-list page could not be read with curl (403); its status was read from a fetch summary. Blocked or empty: ASM Alloy Digest, MakeItFrom, VEM Tooling, suppliersonline, BGH and PACE."
  },
  "sources": {
    "smith-p20": {
      "title": "Smith Metal Centres: P20 (T51620) product datasheet",
      "id": "P20 (T51620)",
      "url": "https://www.smithmetal.com/pdf/tool-steel/p20.pdf",
      "year": 2023,
      "kind": "datasheet",
      "license": "supplier datasheet, cited not reproduced"
    },
    "beul-2311": {
      "title": "Wilhelm Oberste-Beulmann: 1.2311+QT (40CrMnMo7) technical data sheet",
      "id": "1.2311+QT, code 40CrMnMo7",
      "url": "https://www.oberste-beulmann.de/Dateien/Datenblaetter/1.2311.qt.en.pdf",
      "year": 2018,
      "kind": "datasheet",
      "license": "supplier datasheet, cited not reproduced"
    },
    "swiss-2311": {
      "title": "Swiss Steel Group: Formadur 2311 pre-hardened plastic mould steel data sheet, rev. 2",
      "id": "Formadur 2311, AISI P20 / AFNOR 40CMD8",
      "url": "https://swisssteel-group.com/content-media/documents/_import/20260428_SSG_DataSheets_Formadur2311_en_02.pdf",
      "year": 2026,
      "kind": "datasheet",
      "license": "supplier datasheet, cited not reproduced"
    },
    "sij-2311": {
      "title": "SIJ Metal Ravne: SIMOLD 2311 (1.2311) datasheet",
      "id": "SIMOLD 2311, 1.2311, approx. P20",
      "url": "https://cms.sij.si/storage/190/SIMOLD-2311_Metal.pdf",
      "year": 2016,
      "kind": "datasheet",
      "license": "supplier datasheet, cited not reproduced"
    },
    "abrams-12311": {
      "title": "Abrams Industries: PREMIUM 1.2311 steel, standard values (text derived from stahlwissen.de)",
      "id": "PREMIUM 1.2311",
      "url": "https://eu.abrams-industries.com/steel/premium-12311",
      "kind": "web",
      "license": "supplier web page, cited not reproduced"
    },
    "alro-p20": {
      "title": "Alro Steel: P-20 tool steel grade information",
      "id": "AISI P-20",
      "url": "https://www.myalro.com/gradeinfo/Metals_Gridpt.aspx?gp=0335",
      "kind": "web",
      "license": "supplier web page, cited not reproduced"
    },
    "formosa-p20": {
      "title": "Aços Formosa: Plastic mold steels (P-20 family, 1.2311, 1.2312, 1.2738, 1.2316)",
      "id": "P-20 family",
      "url": "https://acosformosa.com.br/en/products/plastic-mold-steels/",
      "year": 2026,
      "kind": "web",
      "license": "supplier web page, cited not reproduced"
    },
    "tm-p20": {
      "title": "TotalMateria: UNS T51620 (P20) material page, chemical composition, physical properties and equivalents",
      "id": "UNS T51620",
      "url": "https://www.totalmateria.com/en-us/material/1241786",
      "kind": "database",
      "license": "database page, cited not reproduced"
    },
    "boxu-s136": {
      "title": "Taizhou Boxumold: P20 vs S136 mold steel comparison (vendor article)",
      "id": "vendor comparison",
      "url": "https://www.boxumold.com/en/comparisons/p20-vs-s136-mold-steel",
      "year": 2026,
      "kind": "web",
      "license": "vendor page, cited not reproduced"
    },
    "doer-2738": {
      "title": "Dörrenberg: 1.2738 (P20+Ni) datasheet, opening paragraph on the DIN EN ISO 4957 grades",
      "id": "1.2738",
      "url": "https://doerrenberg.de/fileadmin/special_steel/files/pdf_en_products_neues_Design/1.2738_en.pdf",
      "kind": "datasheet",
      "license": "supplier datasheet, cited not reproduced"
    },
    "ind-2738": {
      "title": "Industeel (ArcelorMittal): DS Mold 2738 (W 1.2738) datasheet",
      "id": "W 1.2738",
      "url": "https://industeel.arcelormittal.com/fichier/ds-mold-2738",
      "kind": "datasheet",
      "license": "supplier datasheet, cited not reproduced"
    },
    "usgs-cr-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 (USGS)"
    },
    "usgs-mn-2026": {
      "title": "USGS Mineral Commodity Summaries 2026: Manganese",
      "id": "mcs2026-manganese",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-manganese.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-mo-2026": {
      "title": "USGS Mineral Commodity Summaries 2026: Molybdenum",
      "id": "mcs2026-molybdenum",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-crit-2025": {
      "title": "USGS: About the 2025 List of Critical Minerals",
      "id": "2025 list (60 minerals)",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025,
      "kind": "web",
      "license": "public domain (USGS)"
    },
    "ec-crm-2023": {
      "title": "European Commission: Critical raw materials (fifth list 2023, 34 CRMs)",
      "id": "fifth list 2023",
      "url": "https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en",
      "year": 2023,
      "kind": "web",
      "license": "European Commission web page, cited not reproduced"
    },
    "pubchem-cr": {
      "title": "PubChem: Chromium (CID 23976), Safety and Hazards, GHS Classification",
      "id": "CID 23976",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON/?heading=GHS+Classification",
      "year": 2026,
      "kind": "database",
      "license": "PubChem terms (public)"
    },
    "pubchem-mn": {
      "title": "PubChem: Manganese (CID 23930), Safety and Hazards, GHS Classification",
      "id": "CID 23930",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23930/JSON/?heading=GHS+Classification",
      "year": 2026,
      "kind": "database",
      "license": "PubChem terms (public)"
    },
    "pubchem-mo": {
      "title": "PubChem: Molybdenum (CID 23932), Safety and Hazards, GHS Classification",
      "id": "CID 23932",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23932/JSON/?heading=GHS+Classification",
      "year": 2026,
      "kind": "database",
      "license": "PubChem terms (public)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/tool-steel-p20/"
}