Krytox® Lubricants - Frequently Asked Questions
Krytox® is a Chemours™ brand of high-performance, non-flammable and chemically inert lubricants that are compatible with oxygen and have a strong resistance to aggressive chemicals. Krytox® lubricants provide extended life across a wide range of high-temperature applications.
Krytox® oil is a perfluorinated polyether (PFPE). It is a liquid fluoropolymer, similar to liquid Teflon®. Greases are made with various viscosity grades of PFPE oil that are thickened with special PTFE grease thickeners to match the performance capabilities of the oils. Various additives for corrosion protection, extreme pressure conditions, or anti-wear improvement are added to some of the grades.
Who is Chemours?
The Chemours Company (NYSE: CC) is an independently, publicly traded company that originally was the Performance Chemical division within DuPont. The spin-off was completed July 1, 2015.
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, see “DuPont™ Krytox® Performance Lubricants Product Overview”
· 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.
The DuPont™ Krytox® GPL 100
series oils and 200 series greases contains no additives and can be used on
components that come in contact with most chemicals typically used in industry.
applications include valves or bearings, seal barrier fluids, instruments, and oxygen systems.
· The Krytox® GPL 210 series (215, 216, etc.) 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 anti-corrosion additives and have been formulated for applications that need both high load-carrying capacity and anticorrosion protection.
Does Krytox® contain silicone?
No. Krytox® oils and greases do not contain any silicones and there are no silicones used in processing.
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:
| where n=10 to 60
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.
Are Krytox® lubricants flammable?
No. Krytox®; lubricants are not combustible nor do they ignite.
How stable is Krytox® when exposed to chemicals?
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.
Krytox® Performance Lubricants are not only resistant to oxygen and reactive gases, they are inert to virtually all chemicals commonly used in most industries.
Can Krytox® lubricants be used in a clean room environment?
Yes. There is a complete range of standard (1500 series) and extreme (1600 series) vacuum pump oils are available as well as vacuum rated greases such as 240 AB, 240 AC, 240 AD and LVP.
Are Krytox® lubricants pressure sensitive?
No. Krytox® will increase in viscosity under pressure and compress slightly, but will not affect performance.
Can Krytox® be used in medical applications?
Krytox® products have not been approved for medical applications involving permanent or temporary implantation in the human body or permanent or temporary contact with internal body fluids or tissues.
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
General Physical Properties
What is the flash point of Krytox®?
Krytox® is nonflammable. It does not have a flash point because it will not ignite or burn.
What is the recommended temperature range for use of Krytox®?
Krytox® greases and Krytox® oils can be used from temperatures of -95° C (-139°F) up to 343°C (650°F) or higher with relubrication, depending on the grade. Some of the material will evaporate as the temperature rises but Krytox® will not burn or carbonize to form gummy deposits, thus avoiding the condition that typically causes equipment failures.
What is the density of Krytox®?
The density of Krytox® oil and Krytox® grease is approximately 1.9 kg/L, twice the weight of standard grease. This is important when filling bearings by volume. Hydrocarbon preservative oils need to be cleaned from new bearings before applying Krytox®. The preservative can carbonize and may cause premature failure.
We do not have a specific test for measuring the coefficient of friction of Krytox® oils and greases. However, we have run the 4-Ball Wear Test (ASTM 2266) for many Krytox® products. From this test, a coefficient of friction of 0.08 to 0.12 for Krytox® is calculated by dividing torque by load.
What is the dropping point of Krytox®?
Krytox® greases are thickened with PTFE. Dropping point test results (ASTM D-566 and ASTM D-2265) can be confusing or misinterpreted with PTFE-thickened greases. The test is used to determine the “dropping point” (melting point) of a grease, which is the point at which the thickener begins to soften and release base oil. Testing with several different PTFE thickeners shows that a drop of clear oil will be released or separated at around 210°C (410°F) with PTFE-thickened greases. The thickener does not melt until the 320°-335°C (608°-635°F) range. The useful temperature range for the grease is dependent on the base oil.
General Chemical Properties
Does Krytox® oxidize?
PFPEs do not oxidize like hydrocarbons and other synthetics. Because of the PFPE's fluorinated structure, which is inert and nonreactive, they do not oxidize and break down.
How do I clean off Krytox®?
The good news is that you really do not have to clean off Krytox® completely before relubricating. You only need to clean off any solid particulate that is embedded in the grease. If you must clean off the grease completely, TMC offers two different types of cleaning solvents for Krytox®.
Is Krytox® compatible with various seal
Krytox® is compatible with all seal materials. It is chemically inert.
Is Krytox® compatible with plastics and
Krytox® is compatible with all plastics and elastomers. Plastics and elastomers are unchanged and can be used up to their standard operating limit.
Is Krytox®; compatible with aluminum?
There is no reactivity with aluminum at temperatures below 288°C (550°F), but is not recommended for use in equipment that has bearing surfaces made of aluminum.
Can you mix Krytox® with another grease?
We recommend that you do not mix greases. Krytox® greases will not react with the other grease, but they will not mix either and could degrade grease performance.
Can Krytox® greases be mixed?
What happens when they are different viscosities?
Most Krytox® greases can be mixed with each other without concern for reactivity of the oils, thickeners or additives. However, it is not wise to mix different grades, as you can dilute the additives or change the average viscosity of the base oil by doing this. If you mix grease with a lower viscosity base oil into a higher viscosity grease, the average viscosity will drop and the oil might not properly support the load.
What is the shelf life of Krytox®?
Standard Krytox® grease and oil lubricants have an indefinite shelf life if unopened and stored in a clean, dry location. Unopened containers of these fluids have shown no change in properties after ten or more years of storage at ambient temperature. Some specialty products containing soluble additives should be used within three years of manufacture to get the maximum benefit. Currently XP1A series oils, 2A series greases, GPL 226 SR, GPL 227 SR and the XP 1500 vacuum pump fluids are the only products with a shelf life.
Opened containers could be contaminated with moisture or dirt and should be used with caution if their storage history is unknown. If they are clean, uncontaminated, and have been stored so that oil loss is minimized, they are safe for use because the oil and thickener do not degrade with time.
Some oil will separate from the grease after sitting for long storage periods and will tend to accumulate on the surface of grease kept in jars. This does not affect the performance of the grease and can be mixed back into the grease by hand stirring.
Safety and Environmental
Is Krytox® safe for oxygen service?
Yes. It passes all oxygen impact and reactivity tests and is recommended for oxygen service.
Is Krytox® hazardous?
No. Krytox® is a very safe lubricant to ship and use. All Krytox® products are chemically inert. Krytox® oils are even used in cosmetics and the greases as barrier creams. The materials decompose at temperatures above 343°C (650°F); some of the decomposition products are potentially hazardous.
Does Krytox® contain any VOC, Volatile Organic
Krytox® does not contain any Volatile Organic Compounds. Krytox® is made of fluorine, oxygen, and carbon. It does not contain any hydrogen.
Does Krytox® contain synthetic hydrocarbon?
No. Krytox® oil is a synthetic fluoropolymer and the grease is the oil thickened with an ultra low molecular weight PTFE.
Is Krytox&® used as an additive to combustion engine oils?
Krytox® is not useful as an ingredient in oil additives or oils used for internal combustion engines because it is inert and will not mix with the oil.
Is there any moisture in Krytox®?
No. Krytox® grease is moisture-free.
What are the metal levels in Krytox® oils and greases?
Krytox® oils and greases contain only carbon, fluorine, and oxygen. Analysis has shown no detectable levels of metals, hydrocarbons, or any other compounds.
What is the difference between regular Krytox® and Krytox® RFE?
Krytox® RFE is a joint program between Loctite™ and DuPont™. Krytox® RFE is formulated and made exclusively for Loctite. It is only available through Loctite and its authorized distributors.
Food Grade Lubricants
Is Krytox® USDA H-2 certified?
Many Krytox® GPL (general purpose lubricants) have an USDA H-2 rating. H-2 is for lubricants with no contact.
These compounds may be used as lubricants, release agents, or antirust films on equipment and machine parts or in closed systems in locations in which there is no possibility of the lubricant or lubricated part contacting edible products.
Krytox® lubricants are USDA H-1, Food Grade Approved?
Some Krytox® lubricants are USDA H-1 (Food Grade) approval and have been determined by the NSF to be in compliance with FDA 21 CFR, Part 178, Section 178.3570.
These products are acceptable as lubricants with incidental food contact (H-1) for use in and around food processing areas. Such compounds may be used on food processing equipment as a protective anti-rust film, as a release agent on gaskets or seals of tank closures, and as a lubricant for machine parts and equipment in locations in which there is a potential exposure of the lubricated part to food.
Bearings, valves, seals, O-rings
For noncorrosive environments at standard operating temperatures
Bearings, valves, seals, O-rings
For corrosive environments at standard operating temperatures
Bearings and chains
XHT-AC and ACX contain corrosion inhibitor
Chains, compressors, bearings, gear boxes
XHT-500 is formulated for high temperatures
XP-1A5 contains corrosion inhibitor
Vacuum Pump Fluids
Does Krytox® grease meet MIL spec MIL-PRF-27617?
Yes, Krytox® greases are the original products that this military specification was written for and have been certified continuously since the specification was originally written. Krytox® 240AZ (NLGI 1) grease meets MIL spec MIL-PRF-27617 Type I, 240AB meets MIL-PRF-27617 Type II and 240AC meets MIL-PRF-27617 Type III.
What is the proper method for disposing Krytox®?
Krytox® oils and greases are not considered hazardous wastes as manufactured under the EPA RCRA guidelines. Treatment, storage, transportation, recycling and disposal of these products must be in accordance the applicable federal, state/provincial, and local regulations. State/provincial and local regulations may impose waste management requirements, which are more stringent than federal standards. You must review the regulatory requirements specific to your location.
Can Krytox® be recycled?
Yes, TMC Industries is able to reclaim used Krytox® oils, greases and vacuum pump fluids (as well as many other types of fluorinated products) and restore them to their original state for reuse or resale. Contact one of our application engineers at TMC Industries for more information.
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.
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.