{
  "spore": "profile",
  "id": "vespel-sp-3",
  "spore_version": "0.2",
  "family": "polyimides",
  "name": "Vespel SP-3 (15 % MoS2 polyimide)",
  "abbreviation": "SP-3",
  "role": "self-lubricating bearing and seal material for vacuum and dry running",
  "category": "tribology",
  "type": "dry-lubricants",
  "summary": "Vespel SP-3 is a DuPont polyimide grade filled with 15 % molybdenum disulfide (MoS2), sold as isostatic shapes and machined parts for seals and bearings in vacuum or dry environments (DuPont product information sheet). The DuPont typical properties table gives a tensile strength of 58.5 MPa and a strain at break of 4.0 % at 23 °C (ASTM D-1708 or E8), and a friction coefficient of 0.03 in vacuum against 0.25 in air at PV 0.875 MPa·m/s. Its flexural modulus falls from 3275 MPa at 23 °C to 1862 MPa at 260 °C (ASTM D-790), and the DuPont safety data sheet lists combustible dust as its only hazard category.\n",
  "best_for": "Dry-running or vacuum bearings and seals: a typical friction coefficient of 0.03 in vacuum (DuPont)",
  "weakest_at": "Stiffness and strength at high temperature: flexural modulus 1862 MPa at 260 °C against 3275 MPa at 23 °C (DuPont)",
  "identity": {
    "formula": "Polyimide made from pyromellitic dianhydride and 4,4'-oxydianiline, filled with 15 % molybdenum disulfide (MoS2)",
    "designations": [
      {
        "system": "ASTM",
        "code": "D6456-99",
        "note": "Type 3",
        "source": "emco-sp3",
        "where": "At a Glance, certifications line"
      },
      {
        "system": "AMS",
        "code": "3644",
        "note": "Class 5",
        "source": "emco-sp3",
        "where": "At a Glance, certifications line"
      }
    ],
    "source": "dupont-sp3-pis",
    "where": "Title and opening paragraph (SP-3 is a filled polymer); 15 % MoS2 from boedeker-sp3 (15% MoS2 Filled) and kiriuri-sp3; monomers from mfgrobots-vespel (family statement for Vespel)"
  },
  "tags": {
    "environments": [],
    "stresses": [
      "vacuum-and-outgassing",
      "extreme-cold",
      "extreme-heat"
    ],
    "applications": [
      "mechanisms"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Specific gravity (ASTM D792), Vespel SP-3",
      "value": 1.6,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "unit_in_source": "specific gravity, no unit printed",
        "temperature": "not printed"
      },
      "method": "Typical value printed as specific gravity 1.60 (ASTM D792); the number is entered as g/cm3 because the same figure is the density in g/cm3",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Other Properties block, Specific Gravity row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength at 23 °C, Vespel SP-3",
      "value": 58.5,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "23 °C (73 °F)",
        "specimen": "machined isostatic tensile specimens made per ASTM D1708",
        "unit_in_source": "MPa (ksi), printed as 58.5 (8.5)"
      },
      "method": "Typical value, ASTM D-1708 or E8, printed in the DuPont table; the table does not say yield or break",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Tensile Strength row, 23 °C",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Strain at break at 23 °C, Vespel SP-3",
      "value": 4,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "temperature": "23 °C (73 °F)",
        "test": "ASTM D-1708 or E8"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Strain at Break row, 23 °C",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "flexural_strength",
      "label": "Flexural strength at 23 °C, Vespel SP-3",
      "value": 75.8,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "23 °C (73 °F)",
        "test": "ASTM D-790",
        "unit_in_source": "MPa (kpsi), printed as 75.8 (11.0)"
      },
      "method": "Typical value printed in the DuPont table; Kiriuri reprints the same 75.8 MPa",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Flexural Strength row, 23 °C",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "flexural_strength",
      "label": "Flexural strength at 260 °C, Vespel SP-3",
      "value": 39.9,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "260 °C (500 °F)",
        "test": "ASTM D-790",
        "unit_in_source": "MPa (kpsi), printed as 39.9 (5.8)"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Flexural Strength row, 260 °C",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "flexural_modulus",
      "label": "Flexural modulus at 23 °C, Vespel SP-3",
      "value": 3275,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "23 °C (73 °F)",
        "test": "ASTM D-790",
        "unit_in_source": "MPa (kpsi), printed as 3275 (475)"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Flexural Modulus row, 23 °C",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "flexural_modulus",
      "label": "Flexural modulus at 260 °C, Vespel SP-3",
      "value": 1862,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "260 °C (500 °F)",
        "test": "ASTM D-790",
        "unit_in_source": "MPa (kpsi), printed as 1862 (270)"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Flexural Modulus row, 260 °C",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "compressive_stress",
      "label": "Compressive stress at 1 % strain, Vespel SP-3",
      "value": 34.5,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "23 °C (73 °F)",
        "test": "ASTM D-695",
        "unit_in_source": "MPa (kpsi), printed as 34.5 (5.0)"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Compressive Stress at 1 % strain row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "compressive_stress",
      "label": "Compressive stress at 10 % strain, Vespel SP-3",
      "value": 127.6,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "23 °C (73 °F)",
        "test": "ASTM D-695",
        "unit_in_source": "MPa (kpsi), printed as 127.6 (18.5)"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Compressive Stress at 10 % strain row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "compressive_modulus",
      "label": "Compressive modulus at 23 °C, Vespel SP-3",
      "value": 2413,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temperature": "23 °C (73 °F)",
        "test": "ASTM D-695",
        "unit_in_source": "MPa (kpsi), printed as 2413 (350)"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Compressive Modulus row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "izod_impact",
      "label": "Notched Izod impact strength at 23 °C, Vespel SP-3",
      "value": 21.3,
      "bound": "exact",
      "unit": "J/m",
      "scope": "material",
      "conditions": {
        "temperature": "23 °C (73 °F)",
        "test": "ASTM D-256",
        "notch": "notched"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Izod Notched Impact Strength row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "izod_impact",
      "label": "Unnotched Izod impact strength at 23 °C, Vespel SP-3",
      "value": 112,
      "bound": "exact",
      "unit": "J/m",
      "scope": "material",
      "conditions": {
        "temperature": "23 °C (73 °F)",
        "test": "ASTM D-256",
        "notch": "unnotched"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Izod Unnotched Impact Strength row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "wear_rate",
      "label": "Wear rate, Vespel SP-3 (unlubricated in air)",
      "value": 17,
      "value_high": 23,
      "bound": "range",
      "unit": "m/s x 10-10",
      "scope": "material",
      "conditions": {
        "condition": "unlubricated in air, PV 0.875 MPa·m/s (DuPont footnote ††)",
        "unit_in_source": "m/s x 10-10"
      },
      "method": "Range printed in the DuPont table, Wear and Friction block",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Wear and Friction block, Wear Rate row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "friction_coefficient",
      "label": "Friction coefficient at PV 0.875 MPa·m/s, Vespel SP-3",
      "value": 0.25,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "condition": "steady state, unlubricated in air, PV 0.875 MPa·m/s (DuPont footnote **)"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Wear and Friction block, Friction Coefficient row, PV = 0.875 MPa·m/s",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "friction_coefficient",
      "label": "Friction coefficient at PV 3.5 MPa·m/s, Vespel SP-3",
      "value": 0.17,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "condition": "steady state, unlubricated in air, PV 3.5 MPa·m/s (DuPont footnote **)"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Wear and Friction block, Friction Coefficient row, PV = 3.5 MPa·m/s",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "friction_coefficient",
      "label": "Friction coefficient in vacuum, Vespel SP-3",
      "value": 0.03,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "environment": "in vacuum",
        "load_speed_temperature": "not printed in the DuPont table"
      },
      "method": "Typical value printed in the DuPont table, In Vacuum row",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Wear and Friction block, In Vacuum row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of linear expansion, 23 to 260 °C, Vespel SP-3",
      "value": 52,
      "bound": "exact",
      "unit": "µm/m/°C",
      "scope": "material",
      "conditions": {
        "temperature": "23 to 260 °C (73 to 500 °F)",
        "test": "ASTM D-696",
        "unit_in_source": "µm/m/°C, printed as 52 (29) in/in/°F"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Thermal Property block, Coefficient of Linear Expansion row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity at 40 °C, Vespel SP-3",
      "value": 0.47,
      "bound": "exact",
      "unit": "W/m·°C",
      "scope": "material",
      "conditions": {
        "temperature": "40 °C (104 °F)",
        "unit_in_source": "W/m·°C"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Thermal Property block, Thermal Conductivity row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "deformation_under_load",
      "label": "Deformation under 14 MPa load at 50 °C, Vespel SP-3",
      "value": 0.12,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "load": "14 MPa",
        "temperature": "50 °C (122 °F)",
        "test": "ASTM D-621"
      },
      "method": "Typical value printed in the DuPont table",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Thermal Property block, Deformation Under 14 MPa Load row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "moisture_absorption",
      "label": "Water absorption after 24 h at 23 °C, Vespel SP-3",
      "value": 0.23,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "time": "24 h",
        "temperature": "23 °C (73 °F)",
        "test": "ASTM D570"
      },
      "method": "Typical value printed in the DuPont table; Boedeker and Kiriuri reprint the same 0.23 %",
      "status": "ground",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Other Properties block, Water Absorption, 24 h row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "moisture_absorption",
      "label": "Water absorption after 48 h, Vespel SP-3",
      "value": 0.65,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "time": "48 h",
        "temperature": "50 °C (122 °F) as printed by DuPont",
        "test": "ASTM D570"
      },
      "method": "Typical value printed in the DuPont table. Kiriuri prints the same 0.65 % at 23 °C, so the two sources disagree on the test temperature; this entry keeps the DuPont value",
      "status": "ground",
      "note": "Kiriuri (Japanese reprint of the DuPont sheet) prints 48 h at 23 °C; DuPont prints 50 °C. Both sources are cited.",
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Other Properties block, Water Absorption, 48 h row",
      "source_detail": {
        "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
        "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
        "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "DuPont product information; cited, not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Maximum continuous operating temperature, Vespel SP-3",
      "value": 500,
      "bound": "exact",
      "unit": "°F",
      "scope": "material",
      "conditions": {
        "basis": "maximum continuous operating temperature as printed by a distributor; no test condition printed"
      },
      "method": "Printed as 500 °F on the Emco Plastics product page; kept in °F as printed (500 °F equals 260 °C)",
      "status": "ground",
      "source": "emco-sp3",
      "where": "Properties table, Max Continuous Operating Temperature row",
      "source_detail": {
        "title": "Emco Plastics product page, Vespel SP-3",
        "id": "emcoplastics.com/vespel-sp-3",
        "url": "https://www.emcoplastics.com/vespel-sp-3/",
        "kind": "web",
        "license": "distributor page, cited"
      }
    },
    {
      "benchmark": "decomposition_temperature",
      "label": "Decomposition temperature, Vespel SP-3",
      "value": 550,
      "bound": "lower",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "basis": "printed as greater than 550 °C; the material decomposes without melting"
      },
      "method": "Value printed in the DuPont safety data sheet, physical and chemical properties block",
      "status": "ground",
      "note": "Section 10 of the same SDS lists temperature above 450 °C as a condition to avoid.",
      "source": "dupont-sp3-sds",
      "where": "Section 9, Decomposition temperature row",
      "source_detail": {
        "title": "Safety Data Sheet, Vespel SP-3 parts and shapes, version 4.1 (DuPont, Ref. 150000003867)",
        "id": "Issue date 09/07/2023; revision date 06/07/2021",
        "url": "https://www.boedeker.com/Portals/0/Safety%20Data%20Sheets%20SDS/DuPont%20Vespel/Safety-Data-Sheet-SDS-DuPont-Vespel%20SP-3-Boedeker-Plastics-2025.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "supplier safety data sheet, linked not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Humid air, 23 °C",
      "headline": "Vespel SP-3 takes up water slowly and reaches 0.23 % in 24 hours.",
      "effect": "Water absorption is 0.23 % after 24 h at 23 °C and 0.65 % after 48 h (DuPont, printed at 50 °C). Wikipedia says the material absorbs some atmospheric moisture, which lengthens pump-down time in a vacuum; the page gives no figure for that effect.",
      "rating": "low",
      "conditions": {
        "test": "ASTM D570",
        "basis": "typical values; the DuPont sheet gives no equilibrium value at 50 % RH"
      },
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Other Properties block, Water Absorption rows"
    },
    {
      "environment": "Contact with strong acids, strong bases or strong oxidising agents",
      "headline": "The DuPont safety data sheet lists strong acids, strong bases and strong oxidising agents as incompatible with Vespel SP-3.",
      "effect": "No attack rate, concentration, time or temperature is printed for any of the three groups. The sheet gives no corrosion test.",
      "rating": "unknown",
      "conditions": {
        "basis": "incompatibility list only"
      },
      "source": "dupont-sp3-sds",
      "where": "Section 10, Incompatible materials row"
    },
    {
      "environment": "Elevated temperature, 260 °C",
      "headline": "At 260 °C the flexural strength and stiffness are about half their 23 °C values.",
      "effect": "Flexural strength falls from 75.8 MPa at 23 °C to 39.9 MPa at 260 °C, and flexural modulus from 3275 MPa to 1862 MPa (ASTM D-790, DuPont). The sheet gives no ageing time for these figures.",
      "rating": "moderate",
      "conditions": {
        "test": "ASTM D-790, typical values",
        "time": "not printed"
      },
      "source": "dupont-sp3-pis",
      "where": "Typical ISO Properties table, Mechanical Property block, Flexural Strength and Flexural Modulus rows, 23 °C and 260 °C"
    },
    {
      "environment": "Vacuum, including ultra-high vacuum",
      "headline": "Vespel SP-3 is described as giving little outgassing in vacuum, but no TML or CVCM value was read for this grade.",
      "effect": "Wikipedia says Vespel does not produce significant outgassing even at high temperatures and performs well in vacuum down to extremely low cryogenic temperatures. The Copeplastics page lists low outgassing as a property. Neither source gives a mass-loss number for SP-3.",
      "rating": "low",
      "conditions": {
        "basis": "qualitative statements; no ASTM E595 test read for SP-3"
      },
      "source": "wikipedia-vespel",
      "where": "Uses and properties text (summary of the page)"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Combustible dust: if small particles are generated during further processing, handling or by other means, they may form combustible dust concentrations in air. The signal word is Warning and no pictogram is required.",
        "ghs": [],
        "source": "dupont-sp3-sds",
        "where": "Section 2, Product hazard category and Label content"
      },
      {
        "text": "Not a fire or explosion hazard: the product does not burn without an external flame. Carbon monoxide and carbon dioxide are listed as combustion products.",
        "ghs": [],
        "source": "dupont-sp3-sds",
        "where": "Section 5, Specific hazards"
      },
      {
        "text": "Dust exposure limits printed for the dust (OSHA PEL 15 mg/m3 total dust TWA and 5 mg/m3 respirable fraction TWA; ACGIH TLV 3 mg/m3 respirable and 10 mg/m3 inhalable particulate TWA).",
        "ghs": [],
        "source": "dupont-sp3-sds",
        "where": "Section 8, Non-constituent dust exposure limits"
      }
    ],
    "failure_risks": [
      {
        "mode": "Thermal decomposition",
        "trigger": "Temperature above 450 °C, or abnormally long processing time or high temperature",
        "consequence": "The sheet says this can produce irritating and toxic fumes; traces of hydrogen cyanide and isocyanic acid, with carbon monoxide and carbon dioxide, are listed as decomposition products.",
        "severity": "moderate",
        "source": "dupont-sp3-sds",
        "where": "Section 10, Conditions to avoid and Hazardous decomposition products"
      },
      {
        "mode": "Loss of stiffness at high temperature",
        "trigger": "Service at 260 °C",
        "consequence": "Flexural modulus is 1862 MPa at 260 °C against 3275 MPa at 23 °C (ASTM D-790, typical values).",
        "severity": "moderate",
        "source": "dupont-sp3-pis",
        "where": "Typical ISO Properties table, Flexural Modulus row"
      }
    ],
    "side_effects": [
      {
        "text": "Machining dust and fibres from parts or shapes can build up on surfaces and form combustible dust clouds if released.",
        "affects": "Workshop air and surfaces",
        "source": "dupont-sp3-sds",
        "where": "Section 6, Spill cleanup; Section 7, Handling"
      },
      {
        "text": "When overheated, the material releases traces of hydrogen cyanide and isocyanic acid, plus carbon monoxide and carbon dioxide.",
        "affects": "People near an overheated part",
        "source": "dupont-sp3-sds",
        "where": "Section 10, Hazardous decomposition products"
      }
    ],
    "handling": [
      {
        "text": "Wet machining is the preferred method, because the liquid cools the part and reduces dust. Aqueous coolants are preferred. If parts are cleaned after dry machining, rinse with deionised water.",
        "source": "dupont-sp3-sds",
        "where": "Section 8, Engineering controls"
      },
      {
        "text": "Clean fines and dust with HEPA-filtered vacuum equipment. Do not use compressed air, which can generate combustible dust clouds.",
        "source": "dupont-sp3-sds",
        "where": "Section 6, Spill cleanup; Section 7, Handling (Personnel)"
      },
      {
        "text": "Wear leather or cotton gloves when grinding, sawing, routing, drilling or sanding.",
        "source": "dupont-sp3-sds",
        "where": "Section 8, Hand protection"
      },
      {
        "text": "Keep the container closed to prevent contamination, in an area equipped with sprinklers.",
        "source": "dupont-sp3-sds",
        "where": "Section 7, Storage"
      }
    ],
    "mitigations": [
      {
        "text": "Wet machining with mist collection and local exhaust ventilation or dust collection, to keep airborne dust below the exposure limits.",
        "source": "dupont-sp3-sds",
        "where": "Section 8, Engineering controls"
      }
    ]
  },
  "uses": [
    {
      "application": "mechanisms",
      "device": "Seals and plain bearings in vacuum or dry environments",
      "example": "DuPont specifies Vespel SP-3 parts and shapes for seals and bearings in vacuum or dry environments.",
      "source": "dupont-sp3-pis",
      "where": "Opening paragraph"
    },
    {
      "application": "mechanisms",
      "device": "Gears and other wear surfaces for outer space, ultra-high vacuum or dry-gas use",
      "example": "Wikipedia lists seals, plain bearings, gears and other wear surfaces for outer space, ultra-high vacuum or dry-gas applications for SP-3.",
      "source": "wikipedia-vespel",
      "where": "Uses text (summary of the page); no flight or mission is named"
    }
  ],
  "supply": [
    {
      "subject": "Molybdenum (for the MoS2 filler)",
      "producers": [
        {
          "country": "China",
          "share_percent": 37.3,
          "year": 2025
        },
        {
          "country": "Chile",
          "share_percent": 16.2,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 15,
          "year": 2025
        },
        {
          "country": "United States",
          "share_percent": 15.4,
          "year": 2025
        },
        {
          "country": "Mexico",
          "share_percent": 6.5,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: molybdenum is recycled in catalysts, ferrous scrap and superalloy scrap, and recycling may supply as much as 30 % of the apparent supply.",
      "substitutes": [
        "USGS: there is little substitution for molybdenum in its major application in steels and cast irons; the chapter does not discuss molybdenum disulfide lubricants."
      ],
      "source": "usgs-mcs2026-molybdenum",
      "where": "World Mine Production and Reserves table, 2025e column (shares calculated by Space Mushroom from the printed world total of 260,000 t, molybdenum content); Events, Trends, and Issues; Recycling; Substitutes"
    },
    {
      "subject": "Vespel SP-3 parts and shapes",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "dupont-sp3-sds",
      "where": "Section 1, Manufacturer/Supplier; Section 13, Waste disposal methods"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet",
      "type": "datasheet",
      "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
      "year": 2026
    },
    {
      "title": "DuPont Vespel SP-3 parts and shapes, Safety Data Sheet, version 4.1 (hosted by Boedeker Plastics)",
      "type": "sds",
      "url": "https://www.boedeker.com/Portals/0/Safety%20Data%20Sheets%20SDS/DuPont%20Vespel/Safety-Data-Sheet-SDS-DuPont-Vespel%20SP-3-Boedeker-Plastics-2025.pdf",
      "year": 2023
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026, Molybdenum",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf",
      "year": 2026
    }
  ],
  "gaps": [
    "No TML, CVCM or WVR (ASTM E595 outgassing) value for Vespel SP-3 was found. NASA/TM-2000-209897 has no Vespel entry, and the NASA outgassing database did not return an SP-3 row. A TML of 1.09 % and CVCM of 0.00 % appears on a secondary page for SP-1 flight approval; it is not SP-3 and is not used.",
    "No flight, orbital or radiation result for SP-3 was found in the sources opened.",
    "Maximum continuous service temperature is given only by Emco Plastics (500 °F, no test condition) and by Curbell Plastics (550, no unit printed; not used). The DuPont sheet leaves its deflection temperature at 2 MPa blank.",
    "Limiting PV is printed by Curbell Plastics as 40000 with no unit; not used because no unit is printed.",
    "Dielectric constant, dissipation factor, dielectric strength, volume and surface resistivity, specific heat, Poisson's ratio, oxygen index, fatigue endurance limits and equilibrium moisture at 50 % RH are blank in the DuPont sheet.",
    "The DuPont sheet and Kiriuri disagree on the test temperature of the 48 h water absorption value (50 °C against 23 °C). Both are cited; the DuPont figure is kept.",
    "Water absorption, friction and wear test loads, speeds and temperatures for the in-vacuum friction value are not printed.",
    "Steam hydrolysis and resistance to acids and bases were mentioned by Boedeker in a search summary but were not found on the page we opened, so no such numbers are given.",
    "Molybdenum critical-mineral status (USGS 2025 List of Critical Minerals and the EU critical raw materials list) was not opened, so critical_lists is empty.",
    "The repeat unit drawing and molecular formula were not found on any page opened. The identity is given as a description of the polyimide monomers and the filler; the Wikipedia Polyimide page confirms PMDA and ODA for Kapton, not for Vespel.",
    "Monomer supply (pyromellitic dianhydride and oxydianiline) and the producer of the polymer resin were not found in a source opened in this run; DuPont is named as supplier of the parts.",
    "The date of Vespel's introduction and its product history were not found on the pages opened; the Wikipedia summary gives a 1969 patent in its references but does not link it to Vespel.",
    "No source named an orbit, so the environments tag is empty.",
    "Several properties use names that are not in spores/property-canon.yaml (izod_impact, compressive_stress, compressive_modulus, wear_rate, friction_coefficient, deformation_under_load, decomposition_temperature).",
    "Most values come from the DuPont product information sheet, read as text from the PDF in this run. Wikipedia, Emco, Copeplastics, Boedeker, Kiriuri and mfgrobots were read through a summarising fetch, so their wording is paraphrased; they are cited only for composition, uses and the single distributor temperature."
  ],
  "story": {
    "why": "Vespel SP-3 is a polyimide shape with 15 % molybdenum disulfide added to give low friction and wear without oil or grease. DuPont specifies it for seals and bearings in vacuum or dry environments, and the typical friction coefficient in vacuum is 0.03 against 0.25 in air at PV 0.875 MPa·m/s. It is chosen where a lubricant would evaporate, outgas or be unusable, and the trade-off is strength that falls by about half at 260 °C.",
    "uses": [
      {
        "where": "Vacuum and dry-running bearings and seals",
        "line": "DuPont states that Vespel SP-3 parts and shapes are specified for seals and bearings in vacuum or dry environments."
      },
      {
        "where": "Gears and wear surfaces for space and vacuum use",
        "line": "Wikipedia lists seals, plain bearings, gears and other wear surfaces for outer space, ultra-high vacuum or dry-gas applications for SP-3. The page names no mission or flight."
      }
    ],
    "can_do": [
      {
        "label": "Friction in vacuum",
        "line": "In vacuum the friction coefficient is printed as 0.03 (DuPont typical value). The load, speed and temperature for that test are not printed.",
        "benchmark": "friction_coefficient",
        "scope": "material",
        "value": "0.03"
      },
      {
        "label": "Strength at 23 °C",
        "line": "Tensile strength at 23 °C is 58.5 MPa with a strain at break of 4.0 % (ASTM D-1708 or E8, DuPont typical values).",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material",
        "value": "58.5 MPa"
      },
      {
        "label": "Stiffness at 260 °C",
        "line": "Flexural modulus at 260 °C is 1862 MPa, against 3275 MPa at 23 °C (ASTM D-790, DuPont typical values).",
        "benchmark": "flexural_modulus",
        "scope": "material",
        "value": "1862 MPa"
      },
      {
        "label": "Service temperature",
        "line": "The distributor Emco Plastics prints a maximum continuous operating temperature of 500 °F with no test condition.",
        "benchmark": "max_service_temp",
        "scope": "material",
        "value": "500 °F"
      }
    ],
    "compare": "Vespel SP-3 is a dry-running polymer rather than a metal or oil-based lubricant, and its advantage is friction in vacuum, not strength. Its typical friction coefficient is 0.03 in vacuum and 0.25 in air at PV 0.875 MPa·m/s, against a flexural modulus of 3275 MPa at 23 °C that falls to 1862 MPa at 260 °C. The table compares its density, flexural modulus and service temperature.",
    "compare_rows": [
      {
        "label": "Specific gravity",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Flexural modulus at 23 °C",
        "benchmark": "flexural_modulus",
        "scope": "material"
      },
      {
        "label": "Maximum continuous service temperature",
        "benchmark": "max_service_temp",
        "scope": "material"
      }
    ],
    "handling": [
      "The solid part is not classified as a fire or explosion hazard, but machining dust can form combustible clouds. Use wet machining and HEPA vacuum cleaning.",
      "Wear leather or cotton gloves when grinding, sawing, routing, drilling or sanding.",
      "Keep the container closed and avoid overheating above 450 °C, which can release irritating and toxic fumes."
    ],
    "good_for": [
      "Dry-running bearings and seals in vacuum. The DuPont typical friction coefficient in vacuum is 0.03.",
      "Parts that must not outgas a lubricant. Wikipedia says the grade does not produce significant outgassing, though no mass-loss number was found for SP-3."
    ],
    "watch_out": [
      "Strength at high temperature. The flexural modulus is 1862 MPa at 260 °C, against 3275 MPa at 23 °C.",
      "Water absorption of 0.23 % in 24 h at 23 °C, which can add pump-down time in vacuum.",
      "Combustible dust from machining. Use wet cutting and HEPA cleaning."
    ],
    "verdict": "Vespel SP-3 is a dry-running polymer for vacuum bearings and seals. It gives a low friction coefficient in vacuum, and its strength and stiffness drop by about half at 260 °C in DuPont's typical values.",
    "recipe": {
      "line": "Vespel SP-3 is a polyimide filled with molybdenum disulfide. The polyimide is a condensation polymer of pyromellitic dianhydride and 4,4'-oxydianiline (ODA). The grade contains 15 % MoS2 by weight as the solid lubricant.",
      "parts": [
        {
          "name": "Pyromellitic dianhydride (PMDA)",
          "role": "The dianhydride that, with ODA, forms the imide rings of the polyimide chain (Vespel is described as a condensation-type polyimide made from PMDA and ODA)."
        },
        {
          "name": "4,4'-oxydianiline (ODA)",
          "role": "The diamine that, with PMDA, makes up the polyimide repeat unit."
        },
        {
          "name": "Molybdenum disulfide (MoS2)",
          "role": "Solid lubricant filler that gives wear and friction resistance in vacuum and moisture-free environments."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The DuPont safety data sheet gives combustible dust as the only hazard category. The solid part does not burn without an external flame.",
        "points": [
          {
            "label": "The solid part",
            "line": "The sheet says the product does not burn without an external flame and is not a fire or explosion hazard. No pictogram is required, and the signal word is Warning because of dust."
          },
          {
            "label": "Dust from machining",
            "line": "Fine dust and fibres from machining can form combustible dust clouds in air. The sheet gives OSHA limits of 15 mg/m3 total dust and 5 mg/m3 respirable fraction, both as time-weighted averages."
          },
          {
            "label": "In a fire",
            "line": "Combustion products are carbon monoxide and carbon dioxide. Overheating above 450 °C can release traces of hydrogen cyanide and isocyanic acid."
          }
        ],
        "level": 0,
        "verdict": "Combustible dust, not a fire or explosion hazard as a…"
      },
      {
        "title": "If the part overheats",
        "lead": "These are the limits printed by the manufacturer. The sheet gives no field incidents.",
        "points": [
          {
            "label": "Decomposition",
            "line": "The material decomposes without melting, at temperatures greater than 550 °C. The sheet lists temperatures above 450 °C as a condition to avoid."
          },
          {
            "label": "Strength at 260 °C",
            "line": "At 260 °C the flexural strength is 39.9 MPa and the flexural modulus is 1862 MPa, against 75.8 MPa and 3275 MPa at 23 °C (ASTM D-790, DuPont typical values)."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Machining",
            "line": "Wet machining is preferred, with aqueous coolant and mist collection. Clean dust with a HEPA-filtered vacuum, not with compressed air."
          },
          {
            "label": "Storage",
            "line": "Keep the container closed and store the material in an area equipped with sprinklers."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 23,
    "unreachable": 0,
    "caveats": 1,
    "note": "Written by an AI assistant on 2026-11-01 from the DuPont product information sheet and SDS (read as PDF text), the USGS molybdenum table, and distributor and Wikipedia pages read through a summarising fetch. Not yet checked by verify-values."
  },
  "sources": {
    "dupont-sp3-pis": {
      "title": "DuPont Vespel SP-3 Polyimide Isostatic Shapes, Product Information Sheet (Typical ISO Properties)",
      "id": "DuPont VPE-A10869-00-B0614 (printed reference A20 VPE-A40173-00-B0526)",
      "url": "https://www.dupont.com/content/dam/dupont/amer/us/en/vespel/public/documents/en/VPE-A10869-00-B0614.pdf",
      "year": 2026,
      "kind": "datasheet",
      "license": "DuPont product information; cited, not reproduced"
    },
    "dupont-sp3-sds": {
      "title": "Safety Data Sheet, Vespel SP-3 parts and shapes, version 4.1 (DuPont, Ref. 150000003867)",
      "id": "Issue date 09/07/2023; revision date 06/07/2021",
      "url": "https://www.boedeker.com/Portals/0/Safety%20Data%20Sheets%20SDS/DuPont%20Vespel/Safety-Data-Sheet-SDS-DuPont-Vespel%20SP-3-Boedeker-Plastics-2025.pdf",
      "year": 2023,
      "kind": "datasheet",
      "license": "supplier safety data sheet, linked not reproduced"
    },
    "boedeker-sp3": {
      "title": "Boedeker Plastics product page, Vespel SP-3",
      "id": "boedeker.com/Product/Vespel-SP-3",
      "url": "https://www.boedeker.com/Product/Vespel-SP-3",
      "kind": "web",
      "license": "distributor page, cited"
    },
    "emco-sp3": {
      "title": "Emco Plastics product page, Vespel SP-3",
      "id": "emcoplastics.com/vespel-sp-3",
      "url": "https://www.emcoplastics.com/vespel-sp-3/",
      "kind": "web",
      "license": "distributor page, cited"
    },
    "copeplastics-sp3": {
      "title": "Cope Plastics material page, Vespel SP-3",
      "id": "copeplastics.com/materials/vespel-sp-3",
      "url": "https://www.copeplastics.com/materials/vespel-sp-3/",
      "kind": "web",
      "license": "distributor page, cited"
    },
    "kiriuri-sp3": {
      "title": "Kiriuri material data sheet, Vespel SP-3 (Japanese reprint of the DuPont product information sheet, issued 2026-08-27)",
      "id": "Kiriuri, Material Data Sheet (butsuseihyou_vespel-sp-3)",
      "url": "https://files.bcart.jp/kurimotokakou/uploads/zaisitusyoumeisyo/butuseihyou/grade/butsuseihyou_vespel-sp-3.pdf",
      "year": 2026,
      "kind": "web",
      "license": "reseller reprint, cited"
    },
    "wikipedia-vespel": {
      "title": "Vespel, Wikipedia",
      "id": "en.wikipedia.org/wiki/Vespel",
      "url": "https://en.wikipedia.org/wiki/Vespel",
      "kind": "web",
      "license": "CC BY-SA (Wikipedia), cited"
    },
    "mfgrobots-vespel": {
      "title": "Vespel material article, MFG Robots (monomer statement)",
      "id": "mfgrobots.com/Article/material/resin/8298",
      "url": "https://www.mfgrobots.com/Article/material/resin/8298.html",
      "kind": "web",
      "license": "web article, cited"
    },
    "usgs-mcs2026-molybdenum": {
      "title": "Mineral Commodity Summaries 2026, Molybdenum",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/vespel-sp-3/"
}