Krytox® XHT-AC and XHT-ACX

DuPont™ Krytox® XHT-AC and XHT-ACX series greases are 
special high temperature greases with low oil evaporation that 
provide antiwear and rusting protection and are compatible 
with all elastomers and plastics. These greases have excellent 
lubrication over a broad temperature range, but they are 
designed to work best at temperatures over 200 °C (400 °F). 
Krytox® XHT-AC series greases are nonflammable, oxygencompatible, and chemically inert. DuPont™ Krytox® greases 
provide extended lubrication intervals and longer equipment life.
Typical Properties of XHT-AC Series PFPE Grease*
XHT-AC XHT-ACX 
Estimated Useful Range
°C –20/300 –10/300
°F –4/572 14/572
Base Oil Viscosity, cSt
20 °C (68 °F) 1,712 2,610
40 °C (104 °F) 500 738
100 °C (212 °F) 47 65
Oil Viscosity Index 149 158
Oil Pour Point
°C –25 –15
°F –13 5
Antirust Rating, ASTM D-1743 Pass Pass
Maximum Volatility in 22 hr, %
204 °C (400 °F) <1 <0.75
Appearance White, White,
creamy consistency creamy consistency
Specific Gravity at 0 °C (32 °F) 1.99 1.99
Food Contact Approval NSF H-1 NSF H-1
DuPont™ Krytox® XHT-AC Grease
DuPont™ Krytox® XHT-ACX Grease
PRODUCT INFORMATION
The Krytox® XHT-AC series greases are an extension of the 
Krytox® 240 series and Krytox® GPL 22X series but are designed 
to give higher performance in the 204–302 °C (400–575 °F) 
ranges. Krytox® XHT-AC series greases contain sodium nitrite to 
offer anti-corrosion performance. These greases should be used 
below 320 °C (608 °F), where the PTFE thickener could begin to 
melt. The base oil is an extremely viscous oil that provides good 
viscosity and lower evaporation at high temperatures.
Krytox® grease is made to a standard NLGI grade 2. PTFE is the 
standard thickener.
Typical Applications 
Applications for these lubricants are generally of a critical nature 
where temperatures reach extremes that conventional lubricants 
cannot handle. These lubricants are expected to be durable in 
highly aggressive environments. Where failure of components 
is not an option whether because of durability, warranty, safety, 
loss of productivity or down time, Krytox® is the lubricant of 
choice in a wide range of industries and applications.
Typical applications for Krytox® XHT-AC and XHT-ACX include: 
•     paint plant conveyor bearings
•     corrugator and paper machine bearings
•     aluminum can manufacturing bearings
•     welding machines
•     high temperature fans
•     textile equipment
•     tenter frames
•     high temperature ovens
•     conveyor systems in glass and aluminum plants
•     textile calender roll bearings
•     brick kiln car bearings
•     valve lubrication
•     ventilation fan bearing grease
•     rod mills
* This table gives typical properties (not specifications) based on historical production 
performance. DuPont does not make any express or implied warranty that these 
products will continue to have these typical properties.