Krytox® XP Lubricants with Soluble Additives

PRODUCT INFORMATION
DuPont™ Krytox® XP lubricants are formulated using patented 
soluble additives. Typical perfluoropolyether (PFPE) greases 
use solid additives for antirust, antiwear, or extreme pressure 
performance. These components are mixed into the grease and 
held in place by the grease thickener. In the past, there were no 
additives available for the oil, because of the inertness of the oil 
and insolubility of available additives.
Typical Properties
Oil XP 1A0 XP 1A1 XP 1A2 XP 1A3 XP 1A4 XP 1A5 XP 1A6 XP 1A7
Grease XP 2A0 XP 2A1 XP 2A2 XP 2A3 XP 2A4 XP 2A5 XP 2A6 XP 2A7
ISO Grade of Base Oil 5 7 15 32 68 150 220 460 
Estimated Useful 
Temperature Range, °C (°F)
<–70 to 66
(<–94 to 150)
<–70 to104
(<–94 to 220)
–63 to 132 
(–81 to 270)
–60 to 154 
(–76 to 310)
–51 to 179 
(–60 to 355)
–36 to 204 
(–33 to 400)
–36 to 260 
(–33 to 500)
–30 to 288 
(–22 to 550)
Oil Viscosity, cSt
20 °C (68 °F) 
40 °C (104 °F) 
100 °C (212 °F) 
7
4
—
16
8
2
36
15
3
80
30
5
180
60
9
550
160
18
810
240
25
1600
440
42
Oil Viscosity Index — — 59 121 124 134 134 155
Base Oil Pour Point, °C (°F) <–70 (<–94) <–70 (<–94) –63 (–81) –60 (–76) –51 (–60) –36 (–33) –36 (–33) –30 (–22)
Food Contact Approval None None None None None NSF H-1 for 
XP1A5 only None None
The Krytox® XP lubricant line offers greases and oils—with a 
soluble additive in the oil. The soluble additive won’t be washed 
away or left behind with the grease thickener. These patented 
additives enhance the performance of Krytox® PFPE greases and 
oils, giving them improved performance properties. Bearings run 
quieter and wear less, because there are no solid additives to 
make noise. Lower wear will extend bearing and component life. 
The anticorrosion protection of the additive will reduce rusting 
and allow longer grease and bearing life. The extreme pressure 
properties of the additive protect bearings under high loads.
Krytox® XP lubricants are high-quality, ultra-high-performance 
antifriction and antirust lubricants. Formulated with synthetic 
perfluoropolyether fluids, soluble additives, and the most efficient 
polytetrafluoroethylene thickeners available, these lubricants 
exceed the performance requirements of most demanding 
applications.
XP lubricants will hold up under tremendous load conditions, 
preventing metal-to-metal contact and thereby reducing wear. 
The long-term antirust properties repel moisture, providing extra 
protection against corrosion of metal parts and bearing surfaces. 
They also exhibit excellent resistance to water washout when 
used in wet environments.While DuPont™ Krytox® oils are inert and nonreactive to all 
elastomers, plastics, and metals, the soluble additives in the XP 
lubricants are new and have not been tested with all materials. 
It is possible that some reactivity and damage could occur to 
some materials. Initial testing has shown no problems with 
DuPont™ Teflon®, DuPont™ Kalrez®, DuPont™ Viton®, nitrile, and 
silicone rubbers. There is some reactivity of the additive with 
copper, but less so with brass. These additives have not been 
tested at all temperatures and degradation of performance could 
occur at elevated temperatures over a long period of time.
Performance
Wear testing of the additive was done using standard laboratory 
tests to demonstrate the improved performance.
4 Ball Wear tests on oil with the additive compared to oil with no 
additive were run according to ASTM D4172 at 1200 rpm, 20 kg 
load, 107 °C (224 °F) starting temperature, and 1 hr duration. The 
wear scar was measured using a microscope. This method tests 
the wear prevention properties of the oils.
Test Oil Wear Scar Size (mm)
GPL 105 0.44
XP 1A5 0.29
XP 1A5 oil showed a reduction of 34% in wear over the same 
viscosity oil with no additive.
4 Ball Wear tests on grease with the additive compared to 
grease with a typical solid additive were run according to 
ASTM D2266 at 1200 rpm, 20 kg load, 107 °C (224 °F) starting 
temperature, and 1 hr duration. The wear scar was measured 
using a microscope. This method tests the wear prevention 
properties of the greases.
Test Grease Wear Scar Size (mm)
GPL 225 0.42
XP 2A5 0.34
XP 2A5 grease showed a reduction of 19% in wear over a 
current grease with the same viscosity oil and with additives to 
reduce wear and corrosion.
4 Ball EP tests were run on grease and oil according to ASTM 
D2783 for oil and ASTM D2596 for grease. This method tests 
the extreme pressure properties of the oil or additive and its 
ability to carry heavy loads.
Water washout of grease from a bearing was tested by ASTM 
D1264 at 79 °C (175 °F).
Test Grease Grease Removed
XP 2A5 0.25%
Product Load Wear Index, 
No Additive
Load Wear Index 
with XP Additive % Improvement
Oil GPL 103 = 40.9 XP 1A3 = 53.3 30
Grease GPL 206 = 127.8 XP 2A6 = 143.6 12.4
Pin and Vee block tests were conducted according to ASTM 
D3233. The test is a load to failure test that uses progressive 
loading on Vee blocks that squeeze a shaft rotating at 290 rpm. 
The test terminates when the shaft seizes and breaks a shear 
pin or the machine reaches its top loading of 3000 psi on the 
load pressure gauge. The test pieces are submerged in oil. This 
method tests the extreme pressure properties of the oil or 
additive. These tests were run starting at room temperature.
Maximum Load Final Torque 
Test Oil Reached, lb in·lb
GPL 105 3000 96
 XP 1A5 3000 51
XP 1A5 oil showed a reduction of 47% in torque over the same 
viscosity oil with no additive.
Block on Ring tests were run per ASTM D2714. The test runs at 
72 rpm, with a 100 lb normal load for 5000 cycles. The test is a 
line contact configuration. The size of the wear scar on the test 
block is measured. The specimen assembly is partially immersed 
in the lubricant sample during the test. This method tests the 
wear prevention properties of the oil.
Test Oil Wear Scar Size (mm)
GPL 105 0.80
XP 1A5 0.70
XP 1A5 oil showed a reduction of 12% in wear over the same 
viscosity oil with no additives present.
Pin and Vee Block Coupons (Large wear scar on left is from oil 
with no additives; the smaller scar on the right shows the effect of 
XP additives.)Bearing Noise
Solid particles in grease cause bearing noise, and very large 
particles can lead to early failure of the bearing. Small bearings 
and electrical motor bearings are commonly plagued by noise. 
The XP products with soluble additives minimize noise. Various 
greases were tested to show the effects of particles on noise 
level in bearings. Any readings above 25 on the low or high 
band is considered unacceptable for electric motor quality. 
Any amplitude greater than one grid on the oscilloscope is also 
unacceptable for electric motor quality. 
Test Grease Low 
Band
High 
Band Oscilloscope
Competitive Grease
(Large particle additives) 60 95+ Off scale (8+ grids)
Krytox® Grease
(Small particle additives) 17.5 43 3.3 grids
Krytox® Grease
(No solid additives) 20 19.3 1/4 grid
Anticorrosion Protection
Performance of the soluble additives in the XP line is superior to 
additives that are commonly used for anticorrosion protection in 
PFPE grease. 
The corrosion prevention performance of oil with the soluble 
additive was tested against a PFPE oil with no additives using 
a modified version of ASTM D665. Cylindrical C-1018 steel 
coupons were cleaned and coated with oil. They were allowed 
to drip for 1 hr and then were placed into a water bath that was 
stirred and held at 80 °C (176 °F). They were examined at routine 
intervals for corrosion. The water for the test is a modified 
hard water that contains salts and minerals to simulate water 
that normally would be found in industrial applications and is 
somewhat corrosive and similar in action to saltwater.
Time to Final Corrosion
Test Oil Initial Corrosion Rating at 24 hr
GPL 105 Less than1 hr Severe rusting
XP 1A5 None No rusting visible
An additional test was run with corrosion coupons in 80 °C 
(176 °F) agitated hard water for 5 weeks with no rusting visible.
Bearing corrosion prevention performance of grease with the 
soluble additive was tested against a PFPE grease with no 
additives and against a PFPE grease with standard anticorrosion 
additives using the IP-220 (EMCOR) test method. This method 
uses a double row self-aligning bearing that is packed with 
grease. It is a dynamic test that runs partially submerged in 
water for 8 hr, sits for 16 hr, is run again for 8 hr, sits for 16 hr, is 
run again for 8 hr, and is allowed to sit for an additional 108 hr, 
which gives a test time of one week. At this time, the bearing 
is disassembled, and the outer race is examined for rusting. The 
outer race is rated from 0–5 on a standard rating scale, with 0 
having no corrosion and 5 having more than 10% of the surface 
covered with corrosion. The water for the test is a modified hard 
water that contains salts and minerals to simulate water that 
normally would be found in industrial applications and similar in 
corrosion action to saltwater.
Corrosion prevention was also tested by ASTM B117, salt spray 
test. A polished steel test panel that was coated with a 4 mil 
coating of XP 2A5 grease and exposed to a 5% salt solution at 
95 °C (203 °F) for 100 hr passed with no corrosion forming.
Grease corrosion prevention was also tested by ASTM D1743. 
This test uses greased tapered roller bearings that are rotated 
to spread the grease and then are dipped in water and stored 
in a 100% relative humidity environment for 2 days. The XP 2A6 
grease passed with no rusting.
The bearing race on the left clearly shows there is no corrosion 
when the XP additive is present. The bearing in the center shows 
traces of rust with standard additives, and the bearing on the right 
shows heavy rusting with no additives.
Test Grease Final Corrosion Rating
GPL 205
(No additives) 5 (More than 10%)
GPL 225
(Standard antirust additive) 3 (1–5%)
XP 2A5 0 (No corrosion)The information set forth herein is furnished free of charge and is based on technical data that DuPont 
believes to be reliable. It is intended for use by persons having technical skill and at their own discretion 
and risk. Because conditions of use are outside our control, DuPont makes no warranties, express or 
implied, and assumes no liability in connection with any use of this information. Nothing herein is to be 
taken as a license to operate under or a recommendation to infringe any patents or trademarks.
Copyright © 2012 DuPont. The DuPont Oval Logo, DuPont™
, The miracles of science™
, 
Teflon®, Kalrez®, Viton®, Mylar®, and Krytox® are registered trademarks or trademarks of 
E.I. du Pont de Nemours and Company or its affiliates. All rights reserved.
H-58548-4 (11/12) Printed in the U.S.A.
Corrosion-Oxidation Stability Test
The XP oils have been tested in the Corrosion-Oxidation Stability 
Test as per Federal Test Method 791C, 5308.7. This method 
tests the ability of oils to resist oxidation and their tendency 
to corrode various metals. Metal specimens are suspended in 
oil at elevated temperature, and air is blown through the mix. 
After completion, the oil is tested to determine the extent of 
degradation and the metal coupons are examined for corrosion.
Results on XP 1A5 oil after 168 hr at 122 °C (250 °F):
Evaporation loss 1%
Increase in viscosity 1.7%
Change in weight of metals, mg/cm2
:
Magnesium +0.01
Aluminum 0.00
Copper –0.59
Cadmium –0.01
Steel 0.00
Copper alloy 932 –0.22
Elastomer/ 
Plastic
Test 
Temperature GPL 105 Oil XP 1A5 Oil
DuPont™
 Viton® 100 °C (212 °F)
175 °C (347 °F)
0.06
–2.94
0.82
8.18
Silicone, 168 hr 100 °C (212 °F) –1.24 –4.58
Neoprene, 168 hr 100 °C (212 °F) –2.18
EPR, 168 hr 100 °C (212 °F) –0.70
Nitrile 100 °C (212 °F)
175 °C (347 °F)
–2.24
–2.92
–1.55
–3.06
Elastomer Compatibility
Elastomer compatibility screening was done on the XP products. 
Additional testing is being performed to fully characterize if 
materials are affected by the additives in the XP products. The 
chart lists the percentage of swelling after 168 or 672 hr of 
exposure. 
DuPont™ Mylar® and DuPont™ Teflon® have been tested with 
no damage, and additional elastomers are currently being 
tested for compatibility with the additives. DuPont™ Kalrez®
shows the same swell that happens with pure Krytox® at high 
temperatures. Caution should be used with unlisted materials 
until compatibility testing is completed.