spore: profile
id: krytox-143ab
spore_version: 0.2
family: perfluoropolyethers
name: Krytox 143AB perfluoropolyether oil
abbreviation: PFPE
role: liquid lubricant for bearings, valves and seals
category: tribology
type: liquid-lubricants
summary: |
  Krytox 143AB is a clear, colorless perfluoropolyether (PFPE) oil sold by Chemours for lubrication in aerospace and other demanding service. The Chemours aerospace datasheet gives a kinematic viscosity of 1070 cSt at 0 °C, 78 cSt at 40 °C and 10.2 cSt at 100 °C (ASTM D445), a viscosity index of 113, and a pour point of -40 °C (ASTM D97). Its estimated useful range is -40 °C to 232 °C. The safety data sheet classifies it as not a hazardous substance, but its decomposition temperature is 350 °C, and decomposition gives off hydrogen fluoride.
best_for: Liquid lubrication where a nonflammable, chemically inert oil must work from -40 °C to 232 °C; the Chemours datasheet calls the 143 series safe in chemical and oxygen service
weakest_at: 'Volatility and creep: the datasheet shows 17.3 wt% loss in 22 hours at 204 °C, and NASA reports that PFPE oils creep over bearing surfaces'
identity:
  formula: F-(CF(CF3)-CF2-O)n-CF2CF3, n = 10 to 60 (perfluoropolyether, PFPE)
  composition: 'Typical oil by weight: 21.6% carbon, 9.4% oxygen and 69.0% fluorine (Chemours datasheet, PDF page 4)'
  designations:
    - system: Trade name
      code: Krytox 143AB
      source: chemours-aero-datasheet
      where: Table header, 143AB column
  source: chemours-aero-datasheet
  where: Structure and composition text on PDF page 4 ('Krytox 143 series oils'). The SDS gives the substance as 'PFPE fluid' with CAS number 'Trade secret'.
tags:
  stresses:
    - vacuum-and-outgassing
    - extreme-cold
  applications:
    - mechanisms
properties:
  - benchmark: kinematic_viscosity
    label: Kinematic viscosity at -32 °C
    value: 44620
    unit: cSt
    scope: material
    conditions:
      temperature: '-32 °C (-25 °F)'
      method_printed: ASTM D445
      grade: Krytox 143AB
    method: Typical value printed in the Chemours table. The footnote calls the table typical properties, not specifications, and says viscosity may vary within ±10%.
    status: ground
    source: chemours-aero-datasheet
    where: Table 'Typical Properties of Krytox Aerospace Grade Fluorinated Oils', Viscosity row, 143AB column, -32 °C line (printed as 44,620)
  - benchmark: kinematic_viscosity
    label: Kinematic viscosity at 0 °C
    value: 1070
    unit: cSt
    scope: material
    conditions:
      temperature: 0 °C (32 °F)
      method_printed: ASTM D445
    method: Typical value printed in the Chemours table; the footnote says viscosity may vary within ±10%.
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Viscosity row, 143AB column, 0 °C line. The ChemPoint specifications list also prints 1,070 cSt at 0 °C.
  - benchmark: kinematic_viscosity
    label: Kinematic viscosity at 20 °C
    value: 240
    unit: cSt
    scope: material
    conditions:
      temperature: 20 °C (68 °F)
      method_printed: ASTM D445
    method: Typical value printed in the Chemours table; the footnote says viscosity may vary within ±10%.
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Viscosity row, 143AB column, 20 °C line
  - benchmark: kinematic_viscosity
    label: Kinematic viscosity at 40 °C
    value: 78
    unit: cSt
    scope: material
    conditions:
      temperature: 40 °C (104 °F)
      method_printed: ASTM D445
    method: Typical value printed in the Chemours table; the footnote says viscosity may vary within ±10%.
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Viscosity row, 143AB column, 40 °C line. The ChemPoint specifications list also prints 78 cSt at 40 °C.
  - benchmark: kinematic_viscosity
    label: Kinematic viscosity at 100 °C
    value: 10.2
    unit: cSt
    scope: material
    conditions:
      temperature: 100 °C (212 °F)
      method_printed: ASTM D445
    method: Typical value printed in the Chemours table; the footnote says viscosity may vary within ±10%.
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Viscosity row, 143AB column, 100 °C line (the 99 °C line prints 10.5)
  - benchmark: kinematic_viscosity
    label: Kinematic viscosity at 204 °C
    value: 2.1
    unit: cSt
    scope: material
    conditions:
      temperature: 204 °C (400 °F)
      method_printed: ASTM D445
    method: Typical value printed in the Chemours table; the footnote says viscosity may vary within ±10%.
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Viscosity row, 143AB column, 204 °C line
  - benchmark: viscosity_index
    label: Viscosity index
    value: 113
    unit: '-'
    scope: material
    conditions:
      method_printed: ASTM D2270
    method: Typical value printed in the Chemours table
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Viscosity Index row, 143AB column. The ChemPoint specifications list also prints 113.
  - benchmark: pour_point
    label: Pour point
    value: -40
    unit: °C
    scope: material
    conditions:
      method_printed: ASTM D97
      printed_fahrenheit: '-40 °F'
    method: Typical value printed in the Chemours table
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Pour Point row, °C line, 143AB column. The ChemPoint specifications list prints -40 °C (-40 °F).
  - benchmark: density
    label: Oil density at 0 °C
    value: 1.93
    unit: g/mL
    scope: material
    conditions:
      temperature: 0 °C (32 °F)
    method: Typical value printed in the Chemours table; the table gives no ASTM method for oil density
    status: ground
    note: The Chemours SDS, section 9, gives a relative density of 1.86 - 1.91 with no temperature. Both are listed; neither is averaged.
    source: chemours-aero-datasheet
    where: Same table, Oil Density row, 0 °C line, 143AB column. The ChemPoint page prints 1.93 g/mL at 0 °C.
  - benchmark: density
    label: Oil density at 100 °C
    value: 1.75
    unit: g/mL
    scope: material
    conditions:
      temperature: 100 °C (212 °F)
    method: Typical value printed in the Chemours table; the table gives no ASTM method for oil density
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Oil Density row, 100 °C line, 143AB column
  - benchmark: vapor_pressure
    label: Vapour pressure at 38 °C (Knudsen method)
    value: 0.000005
    unit: torr
    scope: material
    conditions:
      temperature: 38 °C (100 °F)
      method_printed: Knudsen
    method: Typical value printed in the Chemours table; the table gives the test method as Knudsen
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Vapor Pressure row, torr line at 38 °C, 143AB column (printed as 5 x 10-6). The ChemPoint page prints 5 x 10−6 torr at 38 °C.
  - benchmark: vapor_pressure
    label: Vapour pressure at 260 °C (Knudsen method)
    value: 0.03
    unit: torr
    scope: material
    conditions:
      temperature: 260 °C (500 °F)
      method_printed: Knudsen
    method: Typical value printed in the Chemours table
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Vapor Pressure row, torr line at 260 °C, 143AB column (printed as 3 x 10-2)
  - benchmark: vapor_pressure
    label: Vapour pressure at 20 °C (NASA table)
    value: 0.0002
    unit: Pa
    scope: material
    conditions:
      temperature: 20 °C
      grade: Krytox 143AB
    method: Value printed in Table 4 of the NASA report. The report does not state the test method for these values.
    status: ground
    note: Different document and possibly a different test from the Chemours Knudsen values above. Both are listed; they are not averaged.
    source: nasa-tm-2000-209924
    where: Table 4, Vapor Pressure at 20 °C column, Pascal, Krytox 143AB row (report page 17)
  - benchmark: vapor_pressure
    label: Vapour pressure at 100 °C (NASA table)
    value: 0.04
    unit: Pa
    scope: material
    conditions:
      temperature: 100 °C
      grade: Krytox 143AB
    method: Value printed in Table 4 of the NASA report. The report does not state the test method for these values.
    status: ground
    note: Different document from the Chemours values above; both are listed, not averaged.
    source: nasa-tm-2000-209924
    where: Table 4, Vapor Pressure at 100 °C column, Pascal, Krytox 143AB row (report page 17)
  - benchmark: vapor_pressure
    label: Vapour pressure at 38 °C for Krytox 143AC (comparison grade)
    value: 8.e-8
    unit: torr
    scope: material
    conditions:
      temperature: 38 °C (100 °F)
      method_printed: Knudsen
      grade: Krytox 143AC
    method: Typical value for a neighbouring grade in the same Chemours table, included for comparison only
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Vapor Pressure row, torr line at 38 °C, 143AC column (printed as 8 x 10-8)
  - benchmark: vapor_pressure
    label: Vapour pressure at 38 °C for Krytox 143AD (comparison grade)
    value: 6.e-9
    unit: torr
    scope: material
    conditions:
      temperature: 38 °C (100 °F)
      method_printed: Knudsen
      grade: Krytox 143AD
    method: Typical value for a neighbouring grade in the same Chemours table, included for comparison only
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Vapor Pressure row, torr line at 38 °C, 143AD column (printed as 6 x 10-9)
  - benchmark: evaporation_loss
    label: Volatility, 22 hours at 149 °C
    value: 1.9
    unit: wt%
    scope: material
    conditions:
      temperature: 149 °C (300 °F)
      time: 22 hours
      method_printed: ASTM D2595
    method: Typical value printed in the Chemours table; the table gives the result as weight percent loss
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Volatility row, wt% loss line at 149 °C, 143AB column
  - benchmark: evaporation_loss
    label: Volatility, 22 hours at 204 °C
    value: 17.3
    unit: wt%
    scope: material
    conditions:
      temperature: 204 °C (400 °F)
      time: 22 hours
      method_printed: ASTM D2595
    method: Typical value printed in the Chemours table
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Volatility row, wt% loss line at 204 °C, 143AB column
  - benchmark: evaporation_loss
    label: Volatility, 22 hours at 260 °C
    value: 76.2
    unit: wt%
    scope: material
    conditions:
      temperature: 260 °C (500 °F)
      time: 22 hours
      method_printed: ASTM D2595
    method: Typical value printed in the Chemours table
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Volatility row, wt% loss line at 260 °C, 143AB column
  - benchmark: distillation_range
    label: Distillation range
    value: 215
    value_high: 290
    bound: range
    unit: °C
    scope: material
    conditions:
      method_printed: ASTM D1160
      pressure: 53 Pa (0.4 torr)
    method: Typical value printed in the Chemours table (printed as 215/290 °C and 420/555 °F)
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Distillation Range row, °C line, 143AB column
  - benchmark: max_service_temp
    label: Estimated useful range, upper limit
    value: 232
    unit: °C
    scope: material
    conditions:
      basis: estimated useful range printed in the Chemours table, not a specification
    method: Estimate printed in the Chemours table (also 450 °F); the page does not give the basis for the estimate
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Estimated Useful Range row, 143AB column (printed as -40 to 232 °C, -40 to 450 °F). The ChemPoint page also prints -40 to 232 °C.
  - benchmark: min_service_temp
    label: Estimated useful range, lower limit
    value: -40
    unit: °C
    scope: material
    conditions:
      basis: estimated useful range printed in the Chemours table, not a specification
    method: Estimate printed in the Chemours table (also -40 °F)
    status: ground
    source: chemours-aero-datasheet
    where: Same table, Estimated Useful Range row, 143AB column
  - benchmark: decomposition_temperature
    label: Decomposition temperature
    value: 350
    unit: °C
    scope: material
    conditions:
      printed: 662 °F / 350 °C
    method: Value printed in SDS section 9. The SDS does not state the test method or atmosphere.
    status: ground
    source: chemours-sds-143ab
    where: Section 9 (Physical and chemical properties), Decomposition temperature row
  - benchmark: melting_point
    label: Melting or freezing point (lower bound as printed)
    value: -55
    bound: lower
    unit: °C
    scope: material
    conditions:
      printed: '> -67 °F / > -55 °C'
    method: SDS section 9 prints the melting or freezing point as greater than -55 °C. This is a bound, not a measured freezing point.
    status: ground
    source: chemours-sds-143ab
    where: Section 9, Melting point/freezing point row
  - benchmark: pressure_viscosity_coefficient
    label: Pressure-viscosity coefficient at 38 °C
    value: 4.2
    unit: Pa-1 x 10^8 (as printed)
    scope: material
    conditions:
      temperature: 38 °C
      fluid: K Fluid (143AB)
    method: Table 5 of the NASA report, which credits the values to Jones et al. 1975. Printed as alpha, Pa-1 x 10^8.
    status: ground
    source: nasa-tm-2000-209924
    where: Table 5, K Fluid (143AB) row, 38 °C column (report page 17)
  - benchmark: pressure_viscosity_coefficient
    label: Pressure-viscosity coefficient at 149 °C
    value: 3
    unit: Pa-1 x 10^8 (as printed)
    scope: material
    conditions:
      temperature: 149 °C
      fluid: K Fluid (143AB)
    method: Table 5 of the NASA report, which credits the values to Jones et al. 1975. Printed as alpha, Pa-1 x 10^8.
    status: ground
    source: nasa-tm-2000-209924
    where: Table 5, K Fluid (143AB) row, 149 °C column (report page 17)
corrosion:
  - environment: Heating to the decomposition temperature
    headline: Decomposition starts at 350 °C and gives off hydrogen fluoride and carbonyl difluoride.
    effect: The Chemours SDS gives a decomposition temperature of 350 °C (662 °F). It lists hydrogen fluoride, carbonyl difluoride, carbon dioxide and carbon monoxide as products of thermal decomposition, and warns that vapours of fluorinated plastics can cause polymer fume fever.
    rating: moderate
    conditions:
      basis: decomposition temperature as printed; the SDS does not give the test method or atmosphere
    source: chemours-sds-143ab
    where: Section 9 (Decomposition temperature) and Section 10 (Hazardous decomposition products)
  - environment: Heating in the ASTM D2595 volatility test
    headline: 'The oil loses weight on heating: 17.3 wt% in 22 hours at 204 °C.'
    effect: ASTM D2595 volatility results printed by Chemours are 1.9 wt% at 149 °C, 17.3 wt% at 204 °C and 76.2 wt% at 260 °C, each over 22 hours. The table gives typical values and does not test vacuum.
    rating: moderate
    conditions:
      time: 22 hours
      method_printed: ASTM D2595
      basis: typical values from the Chemours table
    source: chemours-aero-datasheet
    where: Table, Volatility row, 143AB column
risks:
  hazards:
    - text: The Chemours SDS (rev. 04/15/2026, section 2) classifies Krytox 143AB as not a hazardous substance or mixture, with no pictogram, signal word or hazard statement.
      ghs: []
      source: chemours-sds-143ab
      where: Section 2 (Hazards identification), GHS classification under OSHA HCS
    - text: Thermal decomposition vapours of fluorinated plastics may cause polymer fume fever, with flu-like symptoms, in humans, especially when smoking contaminated tobacco (SDS section 2).
      ghs: []
      source: chemours-sds-143ab
      where: Section 2, Other hazards and hazards from reactions at elevated temperatures
    - text: Hydrogen fluoride, the decomposition product named in the SDS, has its own GHS classification. PubChem prints the signal word Danger and the hazard statements H300 (Fatal if swallowed), H310 (Fatal in contact with skin), H314 (Causes severe skin burns and eye damage) and H330 (Fatal if inhaled). This describes the gas from overheated oil, not the oil itself.
      ghs:
        - H300
        - H310
        - H314
        - H330
      source: pubchem-hf
      where: GHS Classification section (CID 14917), notifications to the ECHA C&L Inventory
  failure_risks:
    - mode: Creep out of the bearing raceway
      trigger: Contact with bearing surfaces; PFPE fluids have low surface tension
      consequence: NASA reports that PFPE fluids, with surface tension of 17 to 25 dynes/cm at 20 °C, creep more than hydrocarbons, esters and silicones. They can dissolve fluorocarbon barrier films with prolonged contact, so those films do not stop the migration.
      severity: moderate
      source: nasa-tm-2000-209924
      where: Creep section
    - mode: Oil loss by evaporation in service
      trigger: Long operation at elevated temperature, or in vacuum
      consequence: NASA states that for a fixed temperature and outlet area, lubricant loss is directly proportional to vapour pressure. It also says PFPE fluids are particularly good candidates compared with conventional lubricants for a similar viscosity range (Figure 4 of the report).
      severity: moderate
      source: nasa-tm-2000-209924
      where: Section on vapour pressure and evaporation (introduction to Table 4)
    - mode: Early bearing failure in full-scale scanner bearings
      trigger: Hard preloaded angular-contact ball bearings at 0.75 GPa mean Hertz stress, dithered through plus or minus 12 degrees
      consequence: Four of five pairs of Krytox 143AB lubricated bearings had failed when the report was written. NASA says 143AB bearing lives were statistically comparable to those lubricated with Bray 815Z oil, and the Pennzane 2001 oil gave a significant life advantage over both.
      severity: moderate
      source: nasa-tm-2001-210966
      where: Full scale bearing tests section and Figure 7
  side_effects:
    - text: Decomposition gives off hydrogen fluoride and carbonyl difluoride. The SDS lists exposure limits for hydrogen fluoride, including a NIOSH TWA of 3 ppm and an ACGIH TWA of 0.5 ppm (as fluorine).
      affects: Workers and the air near overheated oil
      source: chemours-sds-143ab
      where: Section 8, Occupational exposure limits of decomposition products
  handling:
    - text: Use only with adequate ventilation, and do not breathe decomposition products (SDS section 7).
      source: chemours-sds-143ab
      where: Section 7 (Handling and storage), Local ventilation and Advice on safe handling
    - text: Wear safety glasses and wash skin after contact (SDS section 8).
      source: chemours-sds-143ab
      where: Section 8, Eye protection and Skin and body protection
    - text: Keep containers properly labelled. The SDS lists no special storage restrictions with other products, and says there is no decomposition if stored and applied as directed (section 7).
      source: chemours-sds-143ab
      where: Section 7, Conditions for safe storage and Materials to avoid
  mitigations:
    - text: Keep the operating temperature within the estimated useful range of -40 °C to 232 °C, and well below the 350 °C decomposition temperature.
      source: chemours-aero-datasheet
      where: Table, Estimated Useful Range row, 143AB column
    - text: Where evaporation is the limit, the Chemours table shows 143AD with a lower vapour pressure (6 x 10-9 torr at 38 °C) than 143AB (5 x 10-6 torr at 38 °C). 143AD has a higher pour point, so the trade-off must be checked for the design temperature.
      source: chemours-aero-datasheet
      where: Table, Vapor Pressure row at 38 °C and Pour Point row, 143AB and 143AD columns
uses:
  - application: mechanisms
    device: Spacecraft mechanism bearings (ground life tests)
    example: In NASA Glenn's full-scale scanner bearing tests, four of five pairs of Krytox 143AB lubricated bearings had failed when the report was written. All eight pairs lubricated with Bray 815Z had failed by then.
    source: nasa-tm-2001-210966
    where: Full scale bearing tests section; Figure 7
  - application: mechanisms
    device: Liquid lubricants for spacecraft mechanisms (heritage PFPE class)
    example: NASA's space tribology review says the great majority of current spacecraft use either a formulated Pennzane or one of the PFPE materials, and that space lubricants have historically been chosen for their flight heritage.
    source: nasa-tm-2000-209924
    where: Introduction and opening of the liquid lubricants section
  - application: mechanisms
    device: Valves, packings, seals and O-rings in oxygen service (industrial and aerospace listing)
    example: ChemPoint lists Krytox 143AB for valves, packings, seals and O-rings, and under transportation for aerospace and aviation. The Chemours datasheet describes the 143 series as safe in chemical and oxygen service.
    source: chempoint-143ab
    where: Applications section (Maintenance, Repair, Overhaul and Transportation lists)
supply:
  - subject: Krytox 143AB, made by The Chemours Company FC, LLC, 1007 Market Street, Wilmington, Delaware, USA (SDS section 1)
    abundance: Not found in any source read in this run. It is a manufactured fluorinated polymer, and the sources give no feedstock share or production figure.
    producers: []
    critical_lists: []
    recycling: Not found in any source read in this run. The SDS says to dispose of waste oil under local regulations and not into a sewer (section 13).
    substitutes: []
    source: chemours-sds-143ab
    where: Section 1 (Manufacturer or supplier details) and Section 13 (Disposal considerations)
  - subject: 'Fluorine feedstock: fluorspar (calcium fluoride, CaF2), processed into hydrogen fluoride for fluoropolymer chemistry'
    abundance: 'USGS: global mine production of fluorspar was estimated to have decreased by 1% to 10 million tons in 2025.'
    producers:
      - country: China
        production_2025: 6,000 thousand metric tons (mine production)
      - country: Mexico
        production_2025: 1,500 thousand metric tons (mine production)
      - country: Mongolia
        production_2025: 1,500 thousand metric tons (mine production)
    critical_lists: []
    recycling: 'USGS: primary aluminum producers recycle HF and fluorides from smelting operations.'
    substitutes:
      - 'USGS: FSA has been used as an alternative to fluorspar in the production of AlF3 and HF.'
    source: usgs-fluorspar-2026
    where: 'Mineral Commodity Summaries 2026, Fluorspar: Events, Trends, and Issues; World Mine Production and Reserves table (2025 column); Recycling and Substitutes paragraphs'
documents:
  - title: Krytox Aerospace Grade Oils and Greases, product information (Chemours, C-10275, 9/15), hosted by Miller-Stephenson
    type: datasheet
    url: https://miller-stephenson.com/wp-content/uploads/2016/08/Aerospace-PDF.pdf
    year: 2015
  - title: 'Safety Data Sheet: Krytox 143AB, The Chemours Company FC, LLC (revision 04/15/2026, SDS number 1764014-00020)'
    type: sds
    url: https://miller-stephenson.com/wp-content/uploads/2026/08/143AB_4-15-26.pdf
    year: 2026
  - title: NASA/TM-2000-209924, Space Tribology (William R. Jones, Jr., NASA Glenn Research Center)
    type: report
    url: https://ntrs.nasa.gov/api/citations/20000057374/downloads/20000057374.pdf
    year: 2000
  - title: NASA/TM-2001-210966, Relative Lifetimes of Several Space Liquid Lubricants
    type: report
    url: https://ntrs.nasa.gov/api/citations/20010069634/downloads/20010069634.pdf
    year: 2001
  - title: Mineral Commodity Summaries 2026, Fluorspar (U.S. Geological Survey)
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf
    year: 2026
  - title: Hydrogen fluoride (CID 14917), GHS Classification section, PubChem
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/14917/JSON?heading=GHS+Classification
    year: 2026
gaps:
  - No ASTM E595 outgassing result (total mass loss or collected volatile condensable material) for Krytox 143AB was found. The NASA outgassing database was not reachable by search in this run.
  - No flight record for 143AB on a named spacecraft was read. A search snippet mentioned an ESA telecom satellite thruster mechanism using 143AB, but that page was not opened, so it is not used.
  - The ESTL linear ball screw test in NASA/TM-2000-209924 reports that two PFPE lubricants failed rapidly without naming 143AB, so that result is not attributed to 143AB.
  - 'Krytox 143AB has no CAS number in the SDS (CAS-No: trade secret), so no CAS number is given.'
  - The NASA Table 4 viscosity column is headed 'Viscosity at 200 °C, cSt' and prints 230 for 143AB. This does not match the Chemours table (2.1 cSt at 204 °C), so the value is left out.
  - The NASA Table 4 molecular weight (3700) differs from the Chemours and ChemPoint values (3800). Neither is used as a profile property.
  - The SDS gives no vapour pressure, viscosity or outgassing value. The flash point is only 'does not flash' by Pensky-Martens closed cup, with no temperature.
  - No radiation, atomic-oxygen, thermal-vacuum or low-earth-orbit test result for 143AB was found in the sources read.
  - No metal or elastomer compatibility test for 143AB was found in the sources read, so the corrosion section covers decomposition and evaporation only.
  - 'Supply: no producer or production figure for Krytox 143AB itself was found. The fluorspar supply entry gives the mineral feedstock for fluorine chemistry in general, not for this oil, and no critical-mineral status for the oil was found.'
  - 'Hazard data: the PubChem entries describe hydrogen fluoride, the decomposition product, not Krytox 143AB. No PubChem record for 143AB was read.'
  - The ChemPoint technical data sheet (TDS) is behind a request form and was not opened.
  - 'Non-canonical property names used in this profile: distillation_range and pressure_viscosity_coefficient (the others follow the names used by sibling profiles).'
  - The Chemours datasheet PDF has no text layer. Its values were read from rendered page images in this run.
  - No media images were added to this profile.
sources:
  chemours-aero-datasheet:
    title: Typical Properties of Krytox Aerospace Grade Fluorinated Oils and Greases (product information, Chemours C-10275, 9/15)
    id: Chemours, C-10275 (9/15), hosted by Miller-Stephenson
    url: https://miller-stephenson.com/wp-content/uploads/2016/08/Aerospace-PDF.pdf
    year: 2015
    kind: datasheet
    license: Manufacturer document, linked not reproduced
  chemours-sds-143ab:
    title: 'Safety Data Sheet: Krytox 143AB (The Chemours Company FC, LLC, revision 04/15/2026, version 6.1, SDS number 1764014-00020)'
    id: SDS-Identcode 130000024123; product code D10339992
    url: https://miller-stephenson.com/wp-content/uploads/2026/08/143AB_4-15-26.pdf
    year: 2026
    kind: datasheet
    license: Supplier document, linked not reproduced
  chempoint-143ab:
    title: Krytox 143AB Oil, product page (ChemPoint, Chemours Krytox oils)
    id: ChemPoint product page
    url: https://www.chempoint.com/products/chemours/krytox-oils/krytox-oils-for-aerospace-aviation-and-national-de/krytox-143ab-oil
    year: 2026
    kind: web
    license: Distributor page, linked not reproduced
  miller-143ab:
    title: Krytox 143AB Oil, product page (Miller-Stephenson)
    id: Miller-Stephenson product 143AB
    url: https://miller-stephenson.com/product/143ab/
    year: 2026
    kind: web
    license: Distributor page, linked not reproduced
  nasa-tm-2000-209924:
    title: Space Tribology (NASA/TM-2000-209924, William R. Jones, Jr., NASA Glenn Research Center)
    id: NASA/TM-2000-209924; NTRS 20000057374
    url: https://ntrs.nasa.gov/api/citations/20000057374/downloads/20000057374.pdf
    year: 2000
    kind: report
    license: Public domain (NASA)
  nasa-tm-2001-210966:
    title: Relative Lifetimes of Several Space Liquid Lubricants (NASA/TM-2001-210966)
    id: NASA/TM-2001-210966; NTRS 20010069634
    url: https://ntrs.nasa.gov/api/citations/20010069634/downloads/20010069634.pdf
    year: 2001
    kind: report
    license: Public domain (NASA)
  usgs-fluorspar-2026:
    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: Public domain (USGS)
  pubchem-hf:
    title: Hydrogen fluoride (CID 14917), GHS Classification section, PubChem
    id: PubChem CID 14917
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/14917/JSON?heading=GHS+Classification
    year: 2026
    kind: database
    license: PubChem record, public database
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 26
  unreachable: 2
  caveats: 3
  note: Read by an AI assistant on 2026-11-01 from the Chemours datasheet (rendered page images), the Chemours SDS, the ChemPoint and Miller-Stephenson pages, and two NASA reports. The ChemPoint technical data sheet and the NASA outgassing database could not be opened.
story:
  recipe:
    line: 'Krytox 143AB is a perfluoropolyether (PFPE): a saturated chain of carbon, oxygen and fluorine atoms with trifluoromethyl side groups, built from repeat units. The Chemours datasheet gives the structure as F-(CF-CF2-O)n-CF2CF3 with n = 10 to 60. The datasheet does not describe the manufacturing process.'
    parts:
      - name: Carbon
        symbol: C
        share_percent: 21.6
        role: Forms the backbone of the chain together with the CF2 and CF units. The fluorinated chain is fully saturated, so it has no double bonds.
      - name: Oxygen
        symbol: O
        share_percent: 9.4
        role: Ether links between the repeat units. NASA notes that, for unbranched PFPE fluids, the carbon-to-oxygen ratio sets how viscosity changes with temperature.
      - name: Fluorine
        symbol: F
        share_percent: 69
        role: Surrounds the chain and gives the oil its nonflammable, chemically inert character.
  risk_groups:
    - title: For people
      level: 0
      verdict: Not classified hazardous
      lead: The safety data sheet does not classify Krytox 143AB as hazardous. Its thermal decomposition vapours are the hazard to plan for.
      points:
        - label: The oil
          line: The Chemours SDS (revision 04/15/2026) classifies it as not a hazardous substance or mixture, with no GHS label elements.
        - label: Overheating
          line: Above its decomposition temperature of 350 °C, the oil gives off hydrogen fluoride and carbonyl difluoride. The SDS warns that fluoropolymer vapours can cause polymer fume fever.
        - label: Flash
          line: The oil does not flash in a Pensky-Martens closed-cup test, and it will not burn (SDS sections 5 and 9).
    - title: Handling and storage
      points:
        - label: Ventilation
          line: Use only with adequate ventilation, and do not breathe decomposition products (SDS section 7).
        - label: Storage
          line: Keep containers properly labelled. The SDS lists no special storage restrictions with other products, and says there is no decomposition if the oil is stored and applied as directed.
        - label: Temperature
          line: Keep the oil within the estimated useful range of -40 °C to 232 °C given in the datasheet.
  why: 'Krytox 143AB is a perfluoropolyether oil used where a lubricant must be nonflammable, chemically inert and usable across a wide temperature range. Its pour point is -40 °C, its viscosity index is 113, and its estimated useful range runs from -40 °C to 232 °C. Its drawbacks come from the same chemistry: it creeps over bearing surfaces, it evaporates in heat, and its decomposition products are toxic. NASA''s space tribology review says the Pennzane and PFPE families are the two used on most current spacecraft.'
  uses:
    - where: Spacecraft mechanism bearings (ground tests)
      line: In NASA Glenn's full-scale scanner bearing tests, four of five pairs of Krytox 143AB lubricated bearings had failed when the report was written. All eight pairs lubricated with Bray 815Z oil had failed by then.
    - where: Heritage liquid lubricant class
      line: NASA's space tribology review says the great majority of current spacecraft use either a formulated Pennzane or one of the PFPE materials, and that space lubricants have historically been chosen for flight heritage.
    - where: Valves, packings, seals and O-rings
      line: ChemPoint lists Krytox 143AB for valves, packings, seals and O-rings, and under transportation for aerospace and aviation. The Chemours datasheet describes the 143 series as safe in chemical and oxygen service.
  can_do:
    - label: Viscosity over temperature
      benchmark: kinematic_viscosity
      line: Kinematic viscosity falls from 1070 cSt at 0 °C to 78 cSt at 40 °C and 10.2 cSt at 100 °C (ASTM D445, Chemours datasheet). The viscosity index is 113 (ASTM D2270).
    - label: Cold start
      benchmark: pour_point
      line: The pour point is -40 °C (ASTM D97), and the estimated useful range also starts at -40 °C.
    - label: Vacuum and heat loss
      benchmark: vapor_pressure
      line: Vapour pressure is 5 x 10^-6 torr at 38 °C by the Knudsen method (Chemours datasheet). NASA's table gives 2 x 10^-4 Pa at 20 °C.
    - label: Heat
      benchmark: evaporation_loss
      line: In a 22-hour volatility test at 204 °C, 17.3 wt% evaporated (ASTM D2595, Chemours datasheet).
  compare: 'Among the Chemours 143 grades in the datasheet, Krytox 143AB sits in the middle for volatility. At 38 °C its vapour pressure is 5 x 10^-6 torr, against 8 x 10^-8 torr for 143AC and 6 x 10^-9 torr for 143AD, so the heavier grades lose less oil in vacuum and heat. The trade is viscosity: 143AB is thinner than the heavier grades, and it is the more volatile of the two heavier-grade comparisons. In NASA''s Table 4, its 20 °C vapour pressure is the highest of the five PFPE and Pennzane fluids listed.'
  compare_rows:
    - label: Pour point
      benchmark: pour_point
    - label: Vapour pressure at 38 °C
      benchmark: vapor_pressure
    - label: Useful upper temperature
      benchmark: max_service_temp
  handling:
    - The oil is not classified as hazardous in the Chemours safety data sheet. Use adequate ventilation, and do not breathe decomposition products.
    - Keep containers labelled and closed. Wear safety glasses, and wash skin after contact.
    - Keep the oil below the 350 °C decomposition temperature. Above it, the oil gives off hydrogen fluoride.
  good_for:
    - Nonflammable lubrication from -40 °C to 232 °C (estimated useful range) where a chemically inert oil is needed.
    - 'Oxygen and chemical service: the Chemours datasheet describes the 143 series as safe in both.'
    - Spacecraft mechanisms that follow PFPE heritage, where ground tests such as NASA's scanner bearing tests are the evidence.
  watch_out:
    - 'Creep: PFPE oils spread over bearing surfaces and can dissolve fluorocarbon barrier films (NASA).'
    - 'Volatility: 17.3 wt% evaporated in 22 hours at 204 °C (ASTM D2595).'
    - 'Bearing life: four of five 143AB bearing pairs had failed in NASA''s scanner tests, and 143AB was not better than Bray 815Z.'
    - Decomposition above 350 °C gives off hydrogen fluoride.
  verdict: Krytox 143AB is a nonflammable, chemically inert PFPE oil with a wide estimated useful range. Its volatility and creep, and the ground-test bearing results, mean it needs a test on the specific design. The evidence here is ground data and heritage, with no flight record read in this run.