Fluoroelastomer FKM (Viton) FKM

spore: profile
id: fkm-viton
spore_version: 0.2
family: fluoroelastomers
name: Fluoroelastomer FKM (Viton)
abbreviation: FKM
role: O-ring and seal elastomer for vacuum, fuel and chemical service
category: seals-adhesives
type: elastomers-and-o-rings
summary: |
  FKM, sold under the name Viton, is a fluorocarbon rubber used for O-rings and seals. Polymax describes its O-rings as having excellent chemical resistance and an operating range of -15 to 200 degC. Parker's O-ring handbook says it resists high temperature, ozone, oxygen, mineral oil, fuels, aromatics and many solvents, but has poor low-temperature flexibility for static seals.
best_for: Seals that must resist fuels, oils, aromatics and heat up to about 200 degC
weakest_at: Low-temperature flexibility (static limit about -26 degC in Parker's handbook, dynamic limit about -15 to -18 degC) and no outgassing data found in this run
identity:
  formula: 'Fluorocarbon elastomer (FKM, FPM): a fluorine-rich rubber. The sources here give no monomer composition.'
  source: parker-handbook
  where: Section 2.2.7 (Fluorocarbon FKM); Polymax datasheets state that FPM, FKM and Viton are one base material
tags:
  environments: []
  stresses:
    - extreme-heat
    - extreme-cold
  applications:
    - mechanisms
    - propulsion-and-tanks
properties:
  - benchmark: max_service_temp
    label: Operating temperature range (75 Shore A grade)
    value: 200
    unit: degC
    scope: material
    conditions:
      grade: FKM (Viton) 75 ShA, black
      lower_limit: '-15 degC'
    method: Datasheet operating range, stated by the supplier
    status: ground
    source: polymax-75
    where: Header, Operating temperature range
  - benchmark: min_service_temp
    label: Low-temperature resistance (ASTM D 1329 TR10, 75 Shore A grade)
    value: -17
    unit: degC
    scope: material
    conditions:
      test: ASTM D 1329 TR10
    method: Supplier datasheet, typical value
    status: ground
    source: polymax-75
    where: Physical property table
  - benchmark: min_service_temp
    label: Static seal low-temperature limit (general FKM)
    value: -26
    unit: degC
    scope: material
    conditions:
      basis: static seals; Parker gives -15 degF
      special_compounds: some compounds to -46 degC
    method: Statement in Parker O-ring handbook
    status: ground
    source: parker-handbook
    where: Section 2.2.7 (Fluorocarbon FKM)
  - benchmark: max_service_temp
    label: Heat resistance (general FKM)
    value: 204
    unit: degC
    scope: material
    conditions:
      basis: Parker gives 400 degF; higher temperatures are possible with shorter life expectancy
    method: Statement in Parker O-ring handbook
    status: ground
    source: parker-handbook
    where: Section 2.2.7 (Fluorocarbon FKM), heat resistance
  - benchmark: hardness
    label: Hardness (75 Shore A grade)
    value: 79
    unit: Shore A
    scope: material
    conditions:
      test: ASTM D 2240
      grade: 75 ShA, black
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-75
    where: Physical property table
  - benchmark: hardness
    label: Hardness (90 Shore A grade)
    value: 91
    unit: Shore A
    scope: material
    conditions:
      test: ASTM D 2240
      grade: 90 ShA, black
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-90
    where: Physical property table
  - benchmark: tensile_strength
    label: Tensile strength (75 Shore A grade)
    value: 14
    unit: MPa
    scope: material
    conditions:
      test: ASTM D 412
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-75
    where: Physical property table
  - benchmark: tensile_strength
    label: Tensile strength (90 Shore A grade)
    value: 14
    unit: MPa
    scope: material
    conditions:
      test: ASTM D 412
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-90
    where: Physical property table
  - benchmark: elongation
    label: Elongation at break (75 Shore A grade)
    value: 175
    unit: '%'
    scope: material
    conditions:
      test: ASTM D 412
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-75
    where: Physical property table
  - benchmark: elongation
    label: Elongation at break (90 Shore A grade)
    value: 110
    unit: '%'
    scope: material
    conditions:
      test: ASTM D 412
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-90
    where: Physical property table
  - benchmark: compression_set
    label: Compression set (75 Shore A grade)
    value: 22
    unit: '%'
    scope: material
    conditions:
      test: ASTM D 395 B
      time: 22 h
      temperature: 200 degC
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-75
    where: Physical property table
  - benchmark: compression_set
    label: Compression set (90 Shore A grade)
    value: 16
    unit: '%'
    scope: material
    conditions:
      test: ASTM D 395 B
      time: 22 h
      temperature: 200 degC
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-90
    where: Physical property table
  - benchmark: density
    label: Specific gravity (75 Shore A grade)
    value: 1.85
    unit: g/cm3
    scope: material
    conditions:
      test: ASTM D 297
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-75
    where: Physical property table
  - benchmark: density
    label: Specific gravity (90 Shore A grade)
    value: 1.87
    value_high: 1.9
    bound: range
    unit: g/cm3
    scope: material
    conditions:
      basis: printed as 1.87 plus or minus 0.03
    method: Typical value from supplier datasheet
    status: ground
    source: polymax-90
    where: Physical property table
  - benchmark: cte
    label: Coefficient of thermal expansion (expansion, 24 to 191 degC)
    value: 0.00009
    unit: in/in/degF
    scope: material
    conditions:
      basis: fluorocarbon elastomer row, expansion from 75 to 375 degF
    method: Table of linear expansion data in Parker handbook (printed in US units)
    status: ground
    source: parker-handbook
    where: Thermal expansion table, Fluorocarbon Elastomer row (section number not read)
  - benchmark: vacuum_weight_loss
    label: Weight loss in vacuum (V0747-75 fluorocarbon compound)
    value: 0.09
    unit: '%'
    scope: material
    conditions:
      vacuum: about 1 x 10-6 torr
      time: 336 h
      temperature: 25 degC
    method: Parker weight loss of compounds in vacuum test, which is not the ASTM E595 TML method
    status: ground
    source: parker-handbook
    where: Section 3.11.1 Vacuum Weight Loss, Table 3-19
  - benchmark: vacuum_weight_loss
    label: Weight loss in vacuum (V0884-75 fluorocarbon compound)
    value: 0.07
    unit: '%'
    scope: material
    conditions:
      vacuum: about 1 x 10-6 torr
      time: 336 h
      temperature: 25 degC
    method: Parker weight loss of compounds in vacuum test, which is not the ASTM E595 TML method
    status: ground
    source: parker-handbook
    where: Section 3.11.1 Vacuum Weight Loss, Table 3-19
  - benchmark: compression_set
    label: Compression set after air ageing (V0747-75 fluorocarbon compound)
    value: 66
    unit: '%'
    scope: material
    conditions:
      test: air age
      time: 1000 h
      temperature: 204 degC
    method: Parker air age test result, as stated in the handbook text
    status: ground
    source: parker-handbook
    where: Section 3.10.1 High Temperature
  - benchmark: compression_set
    label: Compression set after gamma radiation (V0747-75 fluorocarbon compound)
    value: 66.7
    unit: '%'
    scope: material
    conditions:
      dose: 1 x 10^7 rad gamma
      temperature: room temperature
      compound: V0747-75
    method: Parker radiation table, compression set after gamma exposure, footnote 1; the exponent is read as 10^7 from the PDF text
    status: ground
    source: parker-handbook
    where: Section 3.9.14 Radiation, Data on Radiation Resistant Compounds table
  - benchmark: max_service_temp
    label: Temperature for 90% set after 1000 h (V0747-75 fluorocarbon compound)
    value: 204
    unit: degC
    scope: material
    conditions:
      compound: V0747-75
      basis: temperature at which a 0.139 in cross section ring takes 90% compression set after 1000 h, not exposed to radiation or fluids
    method: Parker radiation table, footnote 2, printed as 204 C (400 F)
    status: ground
    source: parker-handbook
    where: Section 3.9.14 Radiation, Data on Radiation Resistant Compounds table, footnote 2
  - benchmark: min_service_temp
    label: Low-temperature compound V1289-75, advised down to -45 degC
    value: -45
    unit: degC
    scope: material
    conditions:
      compound: V1289-75
      basis: Parker advises considering this compound for temperatures down to -45 degC (-50 degF)
    method: Parker application guidance, stated limit for the compound
    status: ground
    source: parker-handbook
    where: Section 3.10.2 Low Temperature
corrosion:
  - environment: Hot air, 250 degC, 70 h
    headline: Hot air ageing changes hardness and strength only slightly.
    effect: After 70 h at 250 degC in air (ASTM D 573), the 75 Shore A grade gained 1 point of hardness, lost 13% tensile strength and 2% ultimate elongation.
    rating: low
    conditions:
      time: 70 h
      temperature: 250 degC
      standard: ASTM D 573
    source: polymax-75
    where: Aging property table
  - environment: ASTM 101 service liquid, 200 degC, 70 h
    headline: Hot service liquid softens the 75 Shore A grade slightly and swells it by 13%.
    effect: After 70 h at 200 degC in ASTM 101 service liquid (ASTM D 471), hardness changed by -10 points, tensile strength by -15%, ultimate elongation by -6% and volume by +13%.
    rating: moderate
    conditions:
      time: 70 h
      temperature: 200 degC
      standard: ASTM D 471
    source: polymax-75
    where: Aging property table
  - environment: ASTM Fuel C, 23 degC, 70 h
    headline: Fuel C at room temperature has a small effect.
    effect: After 70 h at 23 degC in ASTM Fuel C (ASTM D 471), hardness changed by -4 points, tensile strength by -21%, ultimate elongation by -7% and volume by +4%.
    rating: low
    conditions:
      time: 70 h
      temperature: 23 degC
      standard: ASTM D 471
    source: polymax-75
    where: Aging property table
  - environment: Fuels, oils and chemicals in general
    headline: Parker lists broad resistance to fuels, oils and many chemicals.
    effect: Parker's handbook says FKM has excellent resistance to ozone, oxygen, mineral oil, synthetic hydraulic fluids, fuels, aromatics and many organic solvents and chemicals, and that special compounds improve resistance to acids and fuels.
    rating: none
    conditions:
      basis: qualitative statement, no test conditions given
    source: parker-handbook
    where: Section 2.2.7 (Fluorocarbon FKM)
  - environment: Hot water or steam
    headline: Fluorocarbons harden and take a premature set in hot water or steam.
    effect: Parker says fluorocarbons tend to harden and take a premature set in hot water or steam, where ethylene propylene is generally superior. Parker's radiation table rates its V0747-75 compound Poor for steam and water resistance.
    rating: severe
    conditions:
      basis: qualitative statement and table rating
    source: parker-handbook
    where: Section 3.10.1 High Temperature; Section 3.9.14 Radiation, Data on Radiation Resistant Compounds table
  - environment: Hot air, 204 degC, 1000 h
    headline: The high-temperature compound keeps sealing for many hours at 204 degC, but its life is short at 232 degC.
    effect: After 1000 h in air at 204 degC, Parker's V0747-75 took a 66% set and kept enough recovery to continue sealing for many additional hours. At 232 degC the anticipated useful life falls to about 336 hours.
    rating: moderate
    conditions:
      time: 1000 h
      temperature: 204 degC
      compound: V0747-75
    source: parker-handbook
    where: Section 3.10.1 High Temperature
  - environment: Gamma radiation, 1 x 10^7 rad
    headline: Gamma dose raises the compression set of the fluorocarbon compound.
    effect: After 10^7 rads of gamma radiation at room temperature, Parker's V0747-75 took a 66.7% compression set. Parker's footnote says that above 40% set the compound should be used only at a lower dose level.
    rating: severe
    conditions:
      dose: 1 x 10^7 rad
      temperature: room temperature
    source: parker-handbook
    where: Section 3.9.14 Radiation, Data on Radiation Resistant Compounds table, footnote 1
risks:
  hazards:
    - text: No hazard classification found in this run. The safety data sheet for a specific FKM product was not retrieved.
      ghs: []
      source: parker-handbook
      where: not found
    - text: Vinylidene fluoride is a gas. PubChem lists it as extremely flammable, a gas under pressure that may explode if heated, and a suspected cancer hazard in 11% of notifications. This is for the monomer, not for the FKM compound.
      ghs:
        - H220
        - H280
        - H350
      source: pubchem-vdf
      where: GHS Classification (CID 6369)
    - text: Hexafluoropropylene is a gas. PubChem lists it as harmful if inhaled and as causing respiratory irritation in all notifications, and suspected of causing cancer in 48.6% of notifications. Gases under pressure may explode if heated.
      ghs:
        - H332
        - H335
        - H351
        - H280
      source: pubchem-hfp
      where: GHS Classification (CID 8302)
    - text: Tetrafluoroethylene is a flammable gas. PubChem lists a suspected or confirmed cancer hazard (H350) and damage to organs (H371, reported in 32.2% of notifications). When heated to decomposition it emits highly toxic fumes of fluorine.
      ghs:
        - H220
        - H280
        - H350
        - H371
      source: pubchem-tfe
      where: GHS Classification and Decomposition (CID 8301)
  failure_risks:
    - mode: Stiffening and loss of seal at low temperature
      trigger: Operation below the static or dynamic low-temperature limit (static about -26 degC, dynamic about -15 to -18 degC)
      consequence: Seal loses flexibility and may leak
      severity: moderate
      source: parker-handbook
      where: Section 2.2.7 (Fluorocarbon FKM)
    - mode: Permanent set after long compression at heat
      trigger: Compressed at 200 degC for 22 h
      consequence: The seal recovers less of its shape (22% set for the 75 Shore A grade, 16% for the 90 Shore A grade)
      severity: moderate
      source: polymax-75
      where: Physical property table
    - mode: Premature set in hot water or steam
      trigger: Service in hot water or steam
      consequence: The fluorocarbon hardens and takes a premature set, so it recovers less and may leak
      severity: moderate
      source: parker-handbook
      where: Section 3.10.1 High Temperature
    - mode: Compression set after gamma dose
      trigger: Gamma dose of 1 x 10^7 rads
      consequence: The V0747-75 compound takes a 66.7% set and Parker says to use it only at a lower dose
      severity: critical
      source: parker-handbook
      where: Section 3.9.14 Radiation
  side_effects:
    - text: No side effects found in this run.
      affects: Not sourced
      source: parker-handbook
      where: not found
  handling:
    - text: Use a product safety data sheet for the specific FKM compound before handling; none was retrieved in this run.
      source: polymax-75
    - text: Keep monomer gases away from heat, as the PubChem precautionary codes P210 and P410+P403 advise for vinylidene fluoride.
      source: pubchem-vdf
  mitigations:
    - text: Choose a low-temperature grade or compound when the seal sees cold, as Parker advises for compounds down to -46 degC.
      source: parker-handbook
uses:
  - application: mechanisms
    device: O-rings and seals in aircraft, automotive and chemical equipment
    example: Polymax says FKM has found wide acceptance in the aircraft, automotive and chemical industries. No space mission was named.
    source: polymax-75
    where: Product description
  - application: propulsion-and-tanks
    device: O-ring seals in jet-fuel service (dynamic)
    example: Parker says its V1164-75 fluorocarbon may be used in dynamic applications with the jet fuels in that section because it swells less than 2%. Its low-temperature capability does not normally extend below -29 degC.
    source: parker-handbook
    where: Section 3.9.12.1 Jet Fuels
  - application: mechanisms
    device: Seals in vacuum equipment, where low weight loss matters
    example: Parker's vacuum test gives 0.09% weight loss for V0747-75 and 0.07% for V0884-75 after 336 h at about 1 x 10-6 torr. These are ground results. No spacecraft flight use was named in the sources read.
    source: parker-handbook
    where: Section 3.11.1 Vacuum Weight Loss, Table 3-19
supply:
  - subject: Fluorspar (calcium fluoride), the feedstock for fluorine chemistry
    abundance: 'World mine production was about 10,000 thousand t in 2025 and world reserves about 330,000 thousand t. 2025 mine production in thousand t: China 6,000; Mexico 1,500; Mongolia 1,500; South Africa 410; Vietnam 160 (USGS). Aqueous HF made from fluorspar is the primary feedstock for fluorine chemicals, particularly refrigerants and fluoropolymers (USGS). The United States had no significant fluorspar mine production after 1995 and is 100% net import reliant. Import sources for 2021 to 2024: Mexico 64%, Vietnam 12%, China 10%, South Africa 9%, other 5% (USGS).'
    producers: []
    critical_lists: []
    recycling: Synthetic fluorspar can be made from neutralised waste from uranium enrichment, petroleum alkylation and stainless-steel pickling, but impurities limit its use. Primary aluminium producers recycle HF and fluorides from smelting (USGS).
    substitutes:
      - Fluorosilicic acid has been used as an alternative to fluorspar in making AlF3 and HF (USGS).
    source: usgs-fluorspar
    where: Domestic Production and Use; World Mine Production and Reserves table; Recycling; Substitutes
media: []
documents:
  - title: Polymax FKM (Viton) 75 Shore A O-ring datasheet
    type: datasheet
    url: https://www.polymax.co.uk/media/documents/Datasheet/fkm_viton_75sha_oring_polymax.pdf
    year: 2017
  - title: USGS Mineral Commodity Summaries 2026, fluorspar
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf
    year: 2026
  - title: NASA RP-1124 Revision 4, Outgassing Data for Selecting Spacecraft Materials
    type: report
    url: https://ntrs.nasa.gov/api/citations/19970027853/downloads/19970027853.pdf
    year: 1997
  - title: Parker O-Ring Handbook (copy hosted by the University of Arizona)
    type: report
    url: https://nfc.arizona.edu/sites/default/files/2022-02/parker_o-ring_handbook.pdf
    year: 2022
gaps:
  - 'Outgassing to ASTM E595 (TML and CVCM) for FKM: not found. NASA RP-1124 Revision 4 (NTRS 19970027853) was read in this run and has no Viton or FKM entry. The Parker vacuum weight loss in this profile is a different test.'
  - Parker vacuum weight loss is recorded under the benchmark name vacuum_weight_loss, which is not in property-canon.yaml.
  - Chemours Viton product pages could not be read in this run (blocked). Monomer composition (vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene), the fluorine content by weight for Viton A, B and GF/GLT grades, and the cure system (peroxide or bisphenol) were not stated in any page read in this run.
  - 'Safety data sheet for an FKM compound: not retrieved, so no FKM GHS data. The monomer GHS data are from PubChem and describe the gases, not the compound.'
  - 'Atomic oxygen and spaceflight data for FKM: not searched or not found. No spacecraft flight use was named in the sources read, so the spacecraft seal use is open.'
  - 'Amine compatibility for FKM: Parker''s amine rows were not mapped to the FKM column in this run.'
  - 'Nitrogen tetroxide and other liquid rocket propellants: Parker says most elastomers are degraded by N2O4 and that its special compounds resist it, but the text read does not name FKM.'
  - Producers of FKM or fluorspar (Chemours, Daikin, 3M, Solvay) were not confirmed from a page read in this run.
  - 'Critical-mineral status of fluorspar: not stated in the USGS fluorspar summary read in this run.'
  - Fluid resistance was read from Parker qualitatively and from three Polymax ASTM tests; no peer-reviewed data were found.
  - 'Trelleborg datasheets: not fetched in this run.'
story:
  recipe:
    line: FKM is a fluorocarbon-based synthetic rubber, listed under ASTM D1418 and, as FPM, under ISO/DIN 1629 (Wikipedia). Parker says cross-linking during vulcanization turns the rubber into an elastic material, and that a post-cure may follow. Polymax can supply Viton grades A, B, G, GF, GLT and others on special request. The monomers and the fluorine share of each grade were not stated in any page read in this run.
    parts: []
  risk_groups:
    - title: For people
      lead: No hazard classification was retrieved for FKM in this run.
      points:
        - label: Safety data
          line: Read the safety data sheet for the specific compound before handling. None was retrieved here.
    - title: For the monomers
      verdict: Flammable or pressurised gases, with suspected cancer
      lead: PubChem classifies the monomer gases, not the FKM compound. No classification for FKM itself was found. Flammable or pressurised gases, with suspected cancer hazards
      points:
        - label: Vinylidene fluoride
          line: PubChem lists it as an extremely flammable gas under pressure that may explode if heated. A suspected cancer hazard (H350) is reported by 11% of notifications.
        - label: Hexafluoropropylene
          line: PubChem lists it as harmful if inhaled and as causing respiratory irritation in all notifications. Suspected cancer (H351) is reported by 48.6% of notifications.
        - label: In a fire
          line: Vinylidene fluoride decomposes in heat or fire to toxic and corrosive fumes, including hydrogen fluoride, fluorine and fluorides.
  why: 'FKM (Viton) is a fluorocarbon rubber made into O-rings and seals. Parker''s handbook describes it as resistant to high temperature, ozone, oxygen, mineral oil, fuels, aromatics and many solvents, with very low gas permeability. Its weak point is cold: static seals are limited to about -26 degC.'
  uses:
    - where: O-rings and seals in aircraft, automotive and chemical equipment
      line: Polymax says FKM has found wide acceptance in the aircraft, automotive and chemical industries. No space mission was named in the source.
    - where: Fuel and jet-fuel systems
      line: Parker says its V1164-75 fluorocarbon may be used in dynamic jet-fuel service because it swells less than 2%, but its low-temperature capability does not normally extend below -29 degC.
    - where: Vacuum equipment
      line: Parker's vacuum test gives 0.09% weight loss for V0747-75 after 336 h at about 1 x 10-6 torr. These are ground results; no spacecraft flight use was found.
  can_do:
    - label: Temperature
      value: '-15 to 200 degC'
      line: The 75 Shore A datasheet gives an operating temperature range of -15 to 200 degC. Parker gives up to 204 degC for general FKM, with shorter life at the top end.
    - label: Hardness and strength
      value: 79 Shore A
      line: The 75 Shore A grade has a hardness of 79 Shore A, a tensile strength of 14 MPa and an elongation of 175%. The 90 Shore A grade is harder at 91 Shore A with 110% elongation.
    - label: Compression set
      value: 22%
      line: After 22 hours at 200 degC (ASTM D 395 B), the 75 Shore A grade keeps 22% set and the 90 Shore A grade 16%.
    - label: Cold limit
      value: '-17 degC'
      line: Low-temperature resistance is -17 degC (ASTM D 1329 TR10) for the 75 Shore A grade. Parker gives -26 degC as the static limit for general FKM.
    - label: Steam and radiation
      value: 66.7% set
      line: Parker says fluorocarbons harden and take a premature set in hot water or steam. After 10^7 rads of gamma dose, its V0747-75 compound took a 66.7% compression set.
  compare: FKM is a general-purpose fluoroelastomer for heat and fuel service. The sources read here give its heat and fuel resistance qualitatively and a few numbers for two grades. No comparison with other seal elastomers was made in this run.
  compare_rows:
    - scope: material
      label: Operating range
      benchmark: max_service_temp
    - scope: material
      label: Low-temperature limit
      benchmark: min_service_temp
    - scope: material
      label: Compression set
      benchmark: compression_set
  handling:
    - Read the product safety data sheet before use. None was retrieved here.
    - Choose a low-temperature grade if the seal sees cold.
    - Keep monomer gases away from heat. PubChem gives precautionary codes P210 and P410+P403 for vinylidene fluoride.
  good_for:
    - 'Heat and fuel resistance: operating range of -15 to 200 degC, and resistance to fuels and oils per the Parker handbook.'
    - Low gas permeability, similar to butyl rubber (Parker handbook).
    - 'Vacuum: Parker weight loss is 0.09% for V0747-75 after 336 h at about 1 x 10-6 torr, lower than the nitrile and polyurethane compounds in the same table.'
  watch_out:
    - 'Cold: static limit about -26 degC and dynamic limit about -15 to -18 degC.'
    - Compression set rises with heat over time (22% for the 75 Shore A grade after 22 h at 200 degC).
    - No outgassing (ASTM E595) value was found, so it cannot be cleared for vacuum use from this profile.
    - 'Steam and hot water: Parker says fluorocarbons harden and take a premature set in them, and rates V0747-75 Poor for steam and water.'
    - 'Radiation: at 10^7 rads the V0747-75 compound took a 66.7% set. Parker advises a lower dose where the set is over 40%.'
  verdict: FKM is a dependable seal elastomer for hot fuel and oil service. Parker's data add vacuum weight loss, radiation and steam limits. ASTM E595 outgassing, monomer composition and flight data are still missing from this profile.
sources:
  polymax-75:
    title: FKM (Viton) 75 ShA O-ring datasheet, Polymax
    id: Polymax datasheet fkm_viton_75sha_oring
    url: https://www.polymax.co.uk/media/documents/Datasheet/fkm_viton_75sha_oring_polymax.pdf
    year: 2017
    kind: datasheet
    license: Supplier datasheet, cited
  polymax-90:
    title: FKM (Viton) 90 ShA O-ring datasheet, Polymax
    id: Polymax datasheet fkm_viton_90sha_oring
    url: https://www.polymax.co.uk/media/documents/Datasheet/fkm_viton_90sha_oring_polymax.pdf
    year: 2017
    kind: datasheet
    license: Supplier datasheet, cited
  parker-handbook:
    title: Parker O-Ring Handbook (copy hosted by the University of Arizona)
    id: Parker O-Ring Handbook, copy at the University of Arizona
    url: https://nfc.arizona.edu/sites/default/files/2022-02/parker_o-ring_handbook.pdf
    year: 2022
    kind: handbook
    license: Manufacturer handbook, cited
  usgs-fluorspar:
    title: Mineral Commodity Summaries 2026, Fluorspar, U.S. Geological Survey
    id: USGS MCS 2026, fluorspar
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf
    year: 2026
    kind: report
    license: U.S. Government work, public domain
  pubchem-vdf:
    title: PubChem, Vinylidene fluoride (CID 6369)
    id: PubChem CID 6369
    url: https://pubchem.ncbi.nlm.nih.gov/compound/6369
    kind: database
    license: PubChem, public database
  pubchem-hfp:
    title: PubChem, Hexafluoropropylene (CID 8302)
    id: PubChem CID 8302
    url: https://pubchem.ncbi.nlm.nih.gov/compound/8302
    kind: database
    license: PubChem, public database
  pubchem-tfe:
    title: PubChem, Tetrafluoroethylene (CID 8301)
    id: PubChem CID 8301
    url: https://pubchem.ncbi.nlm.nih.gov/compound/8301
    kind: database
    license: PubChem, public database
  nasa-rp1124:
    title: NASA Reference Publication 1124 Revision 4, Outgassing Data for Selecting Spacecraft Materials
    id: NTRS 19970027853
    url: https://ntrs.nasa.gov/api/citations/19970027853/downloads/19970027853.pdf
    year: 1997
    kind: report
    license: NASA public document
  wikipedia-fluoroelastomer:
    title: Wikipedia, Fluoroelastomer
    id: Wikipedia Fluoroelastomer; lists FKM under ASTM D1418 and FPM under ISO/DIN 1629
    url: https://en.wikipedia.org/wiki/Fluoroelastomer
    kind: web
    license: CC BY-SA 4.0
license: CC-BY-4.0
updated: '2026-10-19'
review:
  status: draft
  method: assistant
  checked_values: 21
  note: Deepened on 2026-10-19 from USGS fluorspar 2026, the Parker O-Ring Handbook, NASA RP-1124 Revision 4, PubChem and Wikipedia, all read in this run.