Frequently Asked Questions (FAQs):

What is Krytox®?
What are the primary differences in Krytox® oils?
Does Krytox® contain silicone?
What are the different grades of Krytox® GPL lubricants and their typical applications?
What is Krytox® made of?
Where can Krytox® lubricants be used?
What is the NLGI consistency of Krytox® grease grades?
Do I need to do anything special before using DuPont™ Krytox® in bearings?
Is ongoing lubrication required once we’ve begun using Krytox®?
Can I mix Krytox® grease with other greases?
What approvals and certifications do Krytox® lubricants have?
Are Krytox® lubricants flammable?
How stable is Krytox® when exposed to chemicals?
Is Krytox® compatible with nonmetallic materials?


Answers to commonly asked questions about Krytox® Oils and Greases
What is Krytox®?

Krytox® is the DuPont brand name for a range of clean, specialty synthetic lubricating materials available in numerous grades for a wide range of applications.

Krytox® lubricants have become the product of choice where extremely high or low temperature performance, non-flammability, longevity, oxygen compatibility and resistance to aggressive chemicals are required.

What are the primary differences in Krytox® oils? 

  • Krytox® XHT oils have additional treatment to make them more thermally stable at temperatures over 300 °C (572 °F) and have very high viscosity to withstand such temperatures and provide adequate lubrication.
  • Krytox® aerospace oils have more strict volatility specifications and are a narrower distillation than GPL oils.
  • Krytox® vacuum pump fluids are distilled to give an excellent vapor pressure and are designed for specific OEM pumps.
  • Krytox® linear oils have a better viscosity index and operate over a wider temperature range compared to conventional lubricants.
  • Krytox® GPL oils are formulated to provide a cost-effective base oil for industrial applications.

To learn more, please request H-58505, “DuPont™ Krytox® Performance Lubricants Product Overview.”

Does Krytox® contain silicone?

No. Krytox® oils and greases do not contain any silicones and there are no silicones used in processing.

What are the different grades of Krytox® GPL lubricants and
their typical applications?

  • The DuPont™ Krytox® GPL 10X oil /20X grease series contains no additives and can be used on components that come in contact with most chemicals typically used in industry. Typical
    applications include valves or bearings, seal barrier fluids,
    instruments, and oxygen systems.
  • The Krytox® GPL 21X series contains molybdenum disulfide for extreme pressure (EP) conditions and should be used for slow speed or extremely heavily loaded applications.
  • The Krytox® GPL 22X series contains sodium nitrite corrosion/anti-wear inhibitor; it also improves load-carrying performance and is ideal for corrosive environments. Typical
    applications are automotive bearings, sealed pump bearings, electric motor bearings and general-purpose bearings.
  • The Krytox® GPL 29X greases have extreme pressure (EP) and anticorrosion additives and have been formulated for applications that need both high load-carrying capacity and
    anticorrosion protection.
  • The Krytox® GPL 2EX lubricants are formulated using new anti-rust additives. This grease is similar to the GPL 22X series greases but contains a non-nitrite anticorrosion
    additive.

What is Krytox® made of?

Krytox® fluorinated oils are a series of low molecular weight, fluorine end-capped, homopolymers of hexafluoropropylene epoxide with the following chemical structure:

F-(CF-CF2-O)n-CF2CF3
       |                                       where n=10 to 60
    CF3

The polymer chain is completely saturated and contains only the elements carbon, oxygen, and fluorine; hydrogen is not present. On a weight basis, typical Krytox® oil contains 21.6% carbon,
9.4% oxygen, and 69.0% fluorine.

DuPont™ Krytox® Performance Lubricants Applications
Where can Krytox® lubricants be used?

Krytox® lubricants can be used in applications where non-flammability, oxygen compatibility, materials compatibility, high-temperature stability, and resistance to aggressive chemicals are requirements. Some examples include:

  • Automotive: wheel bearing grease, CV joint grease, universal  joint grease, fan clutch bearing grease, emission air pump grease, spark plug boot lubricant, weather stripping lubricant, sunroof seal lubricant, clutch throw-out bearing grease, ABS system grease, paint plant conveyor bearings, paint spray system valve lubrication, gasoline pump bearings, windshield wiper motors, oil pressure sensors, truck window lift mechanisms, sintered bearings in motors, leather seats, consoles and trim, flocked and unflocked window seals and channels, door handles, switches, air vents, controls
  • Aviation: fuel-resistant grease, oxygen-compatible grease, ventilation fan bearing grease, cruise missile rear main bearing lubricant, starter bearing grease, emergency generator
    bearing grease, missile launch platform gear lubricant, space shuttle lubricant, sealant
  • Pumps: vacuum pump fluid for corrosive and hazardous service, bearing grease for chemical pumps, O-ring lubricant, barrier fluid between double mechanical seals
  • Industrial: corrugator and paper machine bearings, aluminum can manufacturing bearings, vacuum sputtering machines, welding machines, gear oil, linear bearing lubricant,
    high-temperature fans, cleanrooms, chlorine service, textile equipment, tenter frames, high-speed motors, instrument bearings, sealed-for-life motors, conveyor systems in glass and aluminum plants, textile calender roll bearings, brick kiln car bearings, film blowing machines
  • Nuclear: submerged sump pump bearings, containment cooling fans, snubbers, control rod drive mechanism fan motors
  • Valves: lubricant for valve stem packing, relief valve lubricant, O-ring lubricant, steam turbine control valves, low emissions valve stem packing lubricant
  • Miscellaneous: anti-seize lubricant, bolt thread lubricant, water purifier lubricant, self-contained breathing apparatus lubricant, cryogenic lubricant, vacuum system sealant, drive chains, hydraulic fluids, instrument barrier fluids, heat transfer fluids, geothermal system grease, mold-release agent, fishing reel grease, industrial toast making oven conveyor bearings, windmill gearboxes, glove curing conveyor

To learn more, please request H-58505, “DuPont™ Krytox® Performance Lubricants Product Overview” and/or K-22119, “DuPont™ Krytox® Lubricants Product Selection Guide.”

What is the NLGI* consistency of Krytox® grease grades?

Greases are formed by mixing the base oil with a thickener to form a grease. Krytox® greases use a special high-thickening efficiency, low molecular weight polytetrafluoroethylene (PTFE) with very small particle sizes as their thickener. This is one of the  most thermally stable thickeners for high-temperature, long-term  greases. The higher thickening efficiency of the special PTFE thickener allows DuPont to formulate grease to maximize oil  content for improved grease performance.

* National Lubricating Grease Institute

Greases can be formulated with different viscosity oils to handle different temperatures and load conditions. High-viscosity oils can be used in greases for high temperatures or heavy loads or low-speed applications. Low-viscosity oils can be used in greases where low-temperature properties are important or speeds are higher. Lower amounts of thickener form softer or more fluid-like
greases. Higher solid levels form harder, stiffer greases.

Additives are often added to the grease to enhance anticorrosion protection, raise load-carrying ability or help reduce wear. DuPont standard grease grade is NLGI Grade 2; however, upon request we produce NLGI Grades 000 through 6. For more information on NLGI grade options, please request H-58505, “DuPont™ Krytox® Performance Lubricants Product Overview.”

Do I need to do anything special before using DuPont™ Krytox® in bearings?

Before adding Krytox® grease to a bearing, the bearing should be cleaned of all existing greases, oils, or preservative oils used during storage. If hydrocarbon oils are left in a bearing, the oils can form carbon deposits at high temperatures, which may accelerate bearing failure. Please request K-22116, “New Bearing Preparation with DuPont™ Krytox® Performance Lubricants”  for the
recommended cleaning and re-packing procedure, as well as guidance on how much grease to use and speed considerations.

Is ongoing lubrication required once we’ve begun using Krytox®?

Re-lubrication of bearings may be required, typically every 1 to 3 months for corrugators, depending on the equipment operating temperature. For other applications, re-lubrication
intervals can be from months to years—or potentially never, in the case of sealed systems.

Can I mix Krytox® grease with other greases?

The performance benefits of Krytox® grease will not be realized if Krytox® is mixed with a non-perfluoropolyether (non-PFPE) grease. The performance of the grease mixture will be limited by the properties of the non-PFPE grease in the mixture. Krytox® grease will not react with the other grease or cause decomposition or any hazardous reactions. The mixing tests performed by DuPont have shown that the mixture sometimes softens up by about one penetration grade when it is heated up. This normally will not be enough change to cause any significant problems.

The Krytox® grease will not stop the other lubricant from breaking down from heat and oxidation. It is likely that the additives in the hydrocarbon grease have coated the bearing surfaces and the Krytox® grease will not be able to adhere to the bearing, so most of it might get thrown out of the bearing.

Characteristics of Krytox® Performance Lubricants

What approvals and certifications do Krytox® Lubricants have?

Krytox® lubricants have the following certifications:

  • ISO 9001 Certified Quality Management System
  • ISO 14001 Certified Environmental Management System

In addition, certain grades have the following approvals:

  • MIL-Spec PRF-27617 approved grades for aerospace and aviation use
  • NSF H1-certified lubricants approved for incidental food contact
  • Independently tested and confirmed for LOX and GOX use by major oxygen manufacturers and certification authorities

Are Krytox® lubricants flammable?

No. Krytox® lubricants are not combustible nor do they ignite.

How stable is Krytox® when exposed to chemicals?

DuPont™ Krytox® perfluoropolyether (PFPE) oils and greases thickened with polytetrafluoroethylene (PTFE) exhibit exceptional chemical stability. Krytox® oils and greases will not react with most chemicals (with the exception of Lewis acids and alkali metals) and other lubricants, nor cause them to degrade.

DuPont™ Krytox® Performance Lubricants are not only resistant to oxygen and reactive gases, they are inert to virtually all chemicals commonly used in most industries. For further information, please request K-20564, “DuPont™ Krytox® Lubricants: Chemical Stability.”

Is Krytox® compatible with nonmetallic materials?

Yes. Krytox® oils and greases have been used as plastic or elastomer component lubricants for over 40 years. For more specific information, please request K-20565, “DuPont™ Krytox®
Lubricants Plastics and Elastomer Compatibility.”