Technical Information

Hydraulic Fluids and LubricantsOils, Lubricants, Grease, Jelly

powersolutions.danfoss.com

Technical Information
Hydraulic Fluids and Lubricants

Revision history

2 | © Danfoss | July 2016

Table of revisions
Date

ChangedRev

July 2016

Major update. Updated for Engineering Tomorrow.

0801

November 2015

Minor text change.

0703

Mar 2014

Converted to Danfoss layout – DITA CMSHD

Oct 2002

New EditionAA

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Technical Information
Hydraulic Fluids and LubricantsContents
General Information
Disclaimer............................................................................................................................................................................................4
Introduction........................................................................................................................................................................................4
Health, accident and environmental measures.....................................................................................................................4
API Classes of the base oil..............................................................................................................................................................5
Hydraulic fluid features.................................................................................................................................................................. 5
Viscosity.......................................................................................................................................................................................... 6
Viscosity index (VI)...................................................................................................................................................................... 7
Sealing compatibility................................................................................................................................................................. 9
Air in hydraulic fluid.................................................................................................................................................................10
Bulk modulus..............................................................................................................................................................................11
Compressibility..........................................................................................................................................................................12
Water contamination....................................................................................................................................................................13
Water solubility...............................................................................................................................................................................13
Requirements for Hydraulic Fluids
Fluid type-related standards and specifications.................................................................................................................14
Fluid cleanliness............................................................................................................................................................................. 15
Fluid change intervals.................................................................................................................................................................. 15
Traces of wear metals and contamination............................................................................................................................16
Viscosity and temperature limits..............................................................................................................................................17
Viscosity – Temperature diagrams.......................................................................................................................................... 18
Fire Resistant Hydraulic Fluids
HFA fluids – oil in water emulsions, according to ISO 12 922. ......................................................................................25
HFB fluids – water in oil emulsions, according to ISO 12 922. ...................................................................................... 25
HFC fluids – water polymers / water glycols, according to ISO 12 922. .................................................................... 25
HFD fluids – water free, synthetic fluids according to ISO 12 922. ..............................................................................25
General operating parameters for fire resistant hydraulic fluids..................................................................................26
Specific operating parameters for products running with fire resistant fluids....................................................... 27
Biodegradable Hydraulic Fluids
Biodegradable hydraulic fluids according to ISO 15 380................................................................................................ 28
HETG - Triglyceride hydraulic fluids................................................................................................................................... 29
HEPG – Polyglycol hydraulic fluids.....................................................................................................................................30
HEES – Synthetic ester based hydraulic fluids............................................................................................................... 31
HEPR – Polyalphaolefins and related hydrocarbon hydraulic fluids......................................................................32
Viscosity – Temperature Diagram............................................................................................................................................33
Gear Lubricants
Features............................................................................................................................................................................................. 34
Gear lubricants specifications....................................................................................................................................................34
Example for selecting the kinematic viscosity - transit mixer drive (agitate mode)..............................................35
Viscosity – Temperature diagrams.......................................................................................................................................... 36
Gear Bearing Grease
Features............................................................................................................................................................................................. 38
Dropping point (ISO 2176).................................................................................................................................................... 38
Miscibility of gear bearing grease.......................................................................................................................................38
Storage of gear bearing grease........................................................................................................................................... 38
Consistency.................................................................................................................................................................................38
Preservation fluids and petroleum jelly
Features of preservation fluids..................................................................................................................................................39
Features and application of petroleum jelly........................................................................................................................ 40© Danfoss | July 2016

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Technical Information
Hydraulic Fluids and Lubricants
General Information
Disclaimer
Any warranty applicable for failures related to components of Danfoss Power Solutions does not apply
for any fluid related damages, unless such warranty has been expressly and specifically granted.
The rated data which is published in this Technical Information and Service Manuals is based on the useof premium lubricants containing oxidation, rust and foam inhibitors.

C Caution
It is not permissible to mix lubricants, different additive packages may cause negative interactions. If
lubricant mixing cannot be avoided, fluid manufacturer’s approval is required.
Introduction
The purpose of this manual is to aid the machine operator in the selection of suitable hydraulic fluid, gear
lubricants, gear bearing grease, preservation fluid and petroleum jelly.
The specifications of the lubricant manufacturer and the recommendations of the machine manufacturer
are the basis for selection and subject to change without advance advice. The choice of suitable hydraulicfluids or lubricants is critical for the lifetime, operational safety and efficiency of hydrostatic components
and gears.
If there are any fire hazards, see instructions in Health, accident and environmental measures on page 4.
The selection of the appropriate hydraulic fluid or gear lubricant for a specific application can be madeonly when the different features of the lubricants and the task and conditions under which the machineis to operate are taken into consideration. Content subject to change.
Health, accident and environmental measures
When operating units, which are filled with hydraulic fluids, gear lubricants, grease or preservation fluids(hereafter referred to as lubricants) the operator must consider, among other things, the following
precautionary measures:• Prolonged skin contact with the lubricants is to be avoided. Careful skin cleansing of sticky fluid andregular changing of with lubricant soiled work clothes is required.
• Skin contact with fluid or with heated unit parts is to be avoided, especially at temperatures over 60°C [140 °F].
• Should lubricant get into your eyes, rinse them thoroughly with tap water and see a doctor if
necessary.
• Official regulations must be observed when storing lubricants (e. g. fire extinguishers, emergency
exits).
• If there are any fire hazards, the use of fire resistant fluids is recommended.

•
•
•
•
•
•
•

4 | © Danfoss | July 2016

Clean up spills to avoid slipping (e. g. normal commercial cleaning agents).
Lubricants must not seep into the ground or get into the sewer system.
Concrete floors as foundations can be protected against fluids by being sealed or being painted withfluid-resistant paint.
The first time start up of systems filled with hydraulic fluid, all unnecessary personnel has to stay awayfrom the system.
Old or unusable fluids are to be collected. Quantities above 200 liters [53 US gal] are presently pickedup free of charge in Germany by the authorized collectors, as long as prohibited foreign substances
are not added to these.
For safety reasons, the flash point of the hydraulic fluid should always be at least 20 °C [68 °F] above
the maximum fluid working temperature.
Current official regulations must be observed.

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Technical Information
Hydraulic Fluids and Lubricants
General Information
API Classes of the base oil
Fully formulated hydraulic fluids consist of a blend of a base fluid and an additive package. These basefluids are categorized by the American Petroleum Institute (API) into five groups – API 1509, Appendix E.
The differentiation between them bases on the refining method, amount of saturates, viscosity andpercentage of sulfur. Only groups I to III are products from the refinement of a petroleum crude.
Due to different manufacturing processes, these fluids show different content of saturates and different
viscosity indices (VI). Group I to III fluids can include some VI-improvers, which result in higher VI. GroupIV and V represent synthetic fluids. Thereby group IV includes polyalphaolefines (PAO) and group V allresidual fluids, which do not fit into the group I-IV as example biodegradable HEES, HETG and HEPR.
Base oils specification
Oil type

Mineral base oils

Synthetic base oils

Group

I

II

III

IV1)

Saturates

< 90%

> 90%

> 90%

100%

Viscosity Index

80-12080-120

> 120

> 135

Sulfur> 0,03%< 0,03%< 0,03%—

Manufacturing
Process

Solvent refined

HydrothreatedHydrocracked

Synthesized

Polarity

high

low

unpolarlowVAll other fluids,
including HEES,
HEPG, HEPR

often high1) Group IV - polyalphaolefines

Hydraulic fluid features
Hydraulic fluids have the primary purpose of transferring potential or kinetic energy (pressure andmovements), create volume flow between pump and hydrostatic motor, and reduce the wear of parts
that rub against each other. In addition, they protect the system from corrosion and help carry away theheat produced during energy transformation.
The following tables give an outline of the requirements for hydraulic fluids:
Necessary characteristics of hydraulic fluid
Required

Prerequisites

Volume stability

adequate capacity to separate air

Wear protection capacity

for a hydrodynamic or hydrostatic fluid layer between sliding surfaces
adequate viscosity at operating temperature
for all others wear reducing additives

Corrosion protection capacity

non–aggressive toward customary materials and rust protection additives

Desirable characteristics of hydraulic fluid
Desirable

Prerequisites

Only slight change in usage

adequate oxidation resistancefor some cases of application adequate deemulsification capacity
adequate shear stability, if polymer viscosity index improvers are used

Viscosity–temperature behavior

so that oil changes due to summer and winter operation become redundantadequate Viscosity–Temperature behaviour

Interaction with seals / gaskets

standard sealing materials can be used
minimal characteristics changes of standard elastomers

For most of the identifying characteristics listed in the table, there already exist standards or at least
preferred testing procedures which allow a numerical classification of these identifying features.
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Technical Information
Hydraulic Fluids and Lubricants
General Information
Hydraulic fluid has to perform the following tasks:• Energy transmission• Lubrication• Heat removal
When choosing a hydraulic fluid the following features are most important for consideration:
Viscosity
Viscosity Index (VI) and/or Viscosity Grade (VG) viscosity at 40 °C [104 °F].
Pour point
Shear stability, when polymer VI-improvers are used

•
•
•
•

For any application the features of the hydraulic fluid must be appropriate to the operating environmentof the unit and its components.
The fundamental features of the hydraulic fluids are described below.
Viscosity
A hydraulic fluid has a low viscosity when it is thin and a high viscosity when it is thick. The viscosity
changes with the temperature.
• If the temperature increases, viscosity is reduced.

•

If the temperature decreases, viscosity is increased.

Hydraulic units work under extreme temperature changes, especially in heavy duty vehicles. The viscosity
range of the hydraulic fluid is extremely important.
The hydraulic fluid must be thin enough to flow through the filter, inlet and return pipes without too
much resistance.
On the other hand, the hydraulic fluid must not be too thin, in order to avoid wear due to lack oflubrication and to keep internal leakage within limits.
In the hydraulic business typically the kinematic viscosity 'ν' in mm2/s [SUS] is used for calculations,mainly for calculating the pressure drop in the connecting hoses and pipes.
The other measure is the dynamic viscosity 'η' in mPa•s. Dynamic viscosity is used for calculating the
lubricating film thickness in a journal bearing and similar sliding films between adjacent parts.
Conversion of viscosities:
Dynamic viscosity (η) = kinematic viscosity (ν) x density (ρ): η = ν • ρ (mPa•s)

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Technical Information
Hydraulic Fluids and Lubricants
General Information
Viscosity index (VI)
The viscosity index is a calculated number according to DIN ISO 2909, which describes the viscosity
change of a mineral oil based or a synthetic fluid in dependence of temperature.
• a high viscosity index means a small viscosity change when the temperature changes•

a low index means a large viscosity change when the temperature changes

Viscosity – temperature diagram according to Ubbelohde representing the temperature operating rangeof hydraulic fluids with different viscosity index (VI).
Viscosity – Temperature diagram from Prof. Dr. Ubbelohde

Viscosity-Temperature

Kinematic viscosity [mm2/s]

All e Recht e vorbehalten . Copyrigh t 195 7 by S. Hirze l Verlag , Stuttgart .
Printe d in Germany . Jed e Ar t de s Nachdrucke s bzw . de r Vervielfälti gung einschl. Fotokopieren ist unzulässig und wird rechtlich verfolgt.

from Prof. Dr. L. Ubbelohde
S.Hirzel Verlag, Stuttgart N

2000000
1000000

-40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

120

130

140

150 160

500000300000200000100000
70000
50000
30000
20000

Hydraulic Fluid 2 VI 153

10000

7000
5000
4000
3000
2000
1500
1000
800
700
600
500
400

Hydraulic Fluid 1 VI 100

300
200
150
100 mm 2/s
90
80
70
60

100
90
80
70
60
50

50

40

40

30

30

25

25

20
18
16

20
18
16

14

14

12
11
10

12

9

9

10

8

8

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50

-45

-40

-35

-30

-25 -20 -15 -10 -5-17,78 oC (0 oF)

0

+5 10

15 20 25 3040
50
37,78 oC [100 oF]

Temperatureo

C [oF]

60

70

80

90
100 11098,89 oC (210 oF)
max. 95 oC

P002 062E

Standard mineral oil based (Group I and Group II) hydraulic fluids have a VI value of 90 – 110.

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Technical Information
Hydraulic Fluids and Lubricants
General Information
Hydraulic fluids with a VI larger than 110, e.g. between 130 – 200, are not as sensitive to temperaturechange. These hydraulic fluids distinguish themselves by starting up well and having minimal loss inperformance at low temperatures. At high temperatures a sufficient sealing effect and protection against
wear is achieved by using hydraulic fluids with high viscosity index. The high durability of a hydraulicfluid with a high viscosity index avoids damage and machine breakdown, lowers the operating cost andincreases the life of hydrostatic transmissions and units.

Shear stability
Fluids using polymer viscosity index improver may noticeably shear down (> 20 %) in service. This will
lower the viscosity at higher temperatures below the originally specified value. The lowest expectedviscosity must be used when selecting fluids. Consult your fluid supplier for details on viscosity shear
down.

Pour point
The pour point according to ISO 3016 defines the temperature when the fluids stops to flow. Start up
temperature is recommended to be approximately 15 °C [59 °F] above hydraulic fluid pour point.

Density
The density has to be specified by the manufacturer of the hydraulic fluid. Using hydraulic fluid with ahigh density requires the sufficient diameter of the suction line and/or elevated tank to provide positive
inlet pressure.
Examples for density at 15 °C [59 °F]

8 | © Danfoss | July 2016

Hydraulic fluid typeDensity at 15 °C [59 °F]

Petroleum (mineral) based fluids

0.86 — 0.90 g/ml

Syntetic ester

0.92 — 0.926 g/ml

Rape seed oil

0.92 g/ml

Water

1.00 g/ml

Polyalkylenglykol

1.02 g/ml

HFC

1.08 g/ml

Polyethylenglykol

1.10 g/ml

HFD (phosphate ester)

1.13 g/ml

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Technical Information
Hydraulic Fluids and Lubricants
General Information
Sealing compatibility
The procedure for testing the compatibility of the seal material is described in ISO 6072. In general NBR(Nitrile) or FPM (Fluorocarbon, Viton) is used as seal material for static and dynamic seals. For mosthydraulic fluids both seal materials are suitable, but for some hydraulic fluids only one kind is preferred.
Suitable seal material allocated to the hydraulic fluid is shown in the table below. When orderinghydrostatic products the desired hydraulic fluid should be specified.
Sealing compatibility
Hydraulic fluid

Suitable test material according to ISO 6072

Mineral based hydraulic fluids
Water-in-oil emulsions HFBPolyol esters HFDU
Standards: NBR 1, NBR 2 and FPM 2
Biodegradable synthetic esters HEES
Triglycerides (vegetable-oil-based) HETG
Poly(α-olefin) compounds and related hydrocarbons HEPR*
Water/glycol mixtures HFC

Standards: NBR 1, NBR 2

Alkyl phosphate esters HFDR
Aryl phosphate esters HFDRStandard FPM 2

Poly(alkylene glycol) compounds HEPG
* Depending on the base fluid other seal material may be recommended. Please contact fluid and/or seal

manufacturer for other suitable materials.

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Technical Information
Hydraulic Fluids and Lubricants
General Information
Air in hydraulic fluid
Air in a system is regarded as a contaminant. Air increases the compressibility of the fluid, resulting in a“spongy” system that is less responsive. Air creates a loss of transmitted power, higher operating
temperatures, increased noise levels, and loss of lubricity.
Air typically enters the circuit through the suction line if the seals and fittings are not tight. This free airthen may be dissolved in the hydraulic fluid. Mineral based hydraulic fluid may contain up to 9 % volume
percent dissolved air at atmospheric pressure.
If 1 l [0.264 US gal] of hydraulic fluid is compressed to 100 bar [1450 psi], it may dissolve 9 l [2.377 US gal]of free air if offered.
This is not a problem unless the pressure drops down quickly to a lower level. Then the air becomes free
again and bubbles show up. These bubbles collapse when subjected to pressure, which results incavitation which causes erosion of the adjacent material. Because of this, the greater the air content
within the oil, and the greater the vacuum in the inlet line, the more severe will be the resultant erosion.
The bubbles may also result in a spongy system, slow response time, and poor controllability. Therefore
care must be taken to avoid air to enter the system. If air has entered a system the air release time andfoam characteristic becomes important.

Air release
Air release is a measure for the time needed to release air bubbles (free air) contained in the fluid to thesurfaces. Air typically enters the circuit through the suction line if the seals are not tight as explained
above. Air release time is tested according to ISO 9120.

Foaming characteristic
Foaming characteristic defines the amount of foam collected on the surface in the reservoir and the air
bubble decomposition time. Foaming may become a problem when air has entered the circuit as
explained above, through an insufficient tight suction line. The foaming characteristic of a hydraulic fluid
is tested according to ISO 6247.

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Technical Information
Hydraulic Fluids and Lubricants
General Information
Bulk modulus
While fluids are usually considered incompressible, the pressures that can occur in hydrostatic systems
are of a magnitude that fluid compressibility can be significant. In applications that experience systempressure fluctuations resulting in random high pressure rise rates, consideration must be given to fluid
compressibility when sizing a charge pump to ensure adequate charge pressure.
The amount that a specific fluid compresses for a given pressure increase is related to a fluid property
known as the bulk modulus. The bulk modulus is a measure of a fluids resistance to being compressed. It
depends on pressure and temperature. The air content is important as well especially below 50-100 bar[725-1450 psi]. The higher the air content the more spongy the system (lower bulk modulus). For a given
pressure increase and fluid volume, a fluid with a large bulk modulus will experience a smaller reduction
in volume than a fluid with a low bulk modulus.
Mathematically, bulk modulus is defined as follows:

Where:
E = bulk modulus of the fluid bar [psi]∆p = change in pressure bar [psi]∆V = change in volume l [US gal]
Vo = volume of oil experiencing the change in pressure l [US gal]
Units for bulk modulus are the same as the units for pressure.

Bulk modulus bar [psi]increasing
oscillation
tendency,
SpongyStiffer

Bulk modulus vs. ∆ pressure for different temperatures

o

20 C

o F]

[68
o

40 C

o F]

[104
o

80 C

o F]

[176

D pressure bar [psi]Bulk modulus increases with increasing pressure (stiffer) and decreases with increasing temperature(spongy).
Examples for bulk modulus at 22 °C [71.6 °F]© Danfoss | July 2016

@Pressure

Water

HFC

HFD

Mineral(petroleum) HF

140 bar [2031 psi]

11 00015 500

16 000

15 000300 bar [4351 psi]

15 000

19 00019 500

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Technical Information
Hydraulic Fluids and Lubricants
General Information
Compressibility
Compressibility is the reciprocal of the bulk modulus. It defines how much a fluid can be compressed.

Examples for compressibility at 22 °C [71.6 °F]@Pressure

Water

HFC

HFD

Mineral(petroleum) HF

140 bar [2031 psi]

91 x 10-6

65 x 10-6

63 x 10-6

67 x 10-6300 bar [4351 psi]

67 x 10-6

53 x 10-6

51 x 10-6

63 x 10-6

Fluid compressibility becomes a concern for a hydrostatic system which has large volumes of oil underpressure, such as long or large system lines, and experiences high system pressure spikes during
operation.
To understand the nature of the problem that can be associated with fluid compressibility, consider what
happens when a system experiences an increase in load. An increase in load requires more torque fromthe motor, and consequently, an increase in system pressure. When the system pressure increases, thefluid in the high pressure side of the hydrostatic loop is compressed.

100 bar[1450 psi]

DV

200 bar[2901 psi]
The illustration shows a simple model consisting of a cylinder whose piston compresses the fluid tocreate a pressure of 100 bar [1450 psi]. If a load forces the piston to move a small distance to the left, thefluid compresses even more, resulting in the pressure increasing to 200 bar [2900 psi].
The fluid at this pressure now occupies a smaller volume than the fluid did at 100 bar [1450 psi]. At thesame time, the volume on the rod side of the piston increases. If we imagine that the rod side of thepiston is also filled with fluid, then a void is created on this side of the piston when the fluid against thepiston face is compressed. To keep the rod side of the piston full of fluid, additional fluid must be added
to this side of the piston.
Calculation:
The hydraulic fluid volume under pressure in the cylinder is 10 l [2.64 US gal]. As approach the bulk
modulus for 140 bar [2031 psi] as shown above is used.

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Technical Information
Hydraulic Fluids and Lubricants
General Information
Water contamination
Non-dissolved water in a fluid is to be considered as contamination. It is one of the frequent reasons forthe failure of a hydraulic system. Increased content of water in a lubricant can lead to corrosion of parts,
water vapor cavitation, foam formation, filter clogging, oxidation of the fluid, depleting of additives andconsequentially enhanced wear or a failure of the system.
Furthermore the polymer seal material could be attacked by the fluid leading to leakages.
The water contamination of the fluid can have different reasons as for example condensing of water,
leakage of rain water into the system, leakage of cooling water and others.
Water solubility
Base oils of different types have limited water solubility. Blending the base oils with additives leads to asignificant increase of the water solubility. Also the amount and the kind of used additive packages are
crucial for this property. There is a general thumb rule: the higher the amount of additives, the higher thewater solubility of a fluid. Consequently different fluid types have different water absorptive capacity,which depends on the molecular structure and the additive packages of the fluid. Some fluid types areable to dissolve more water by integrating it in the molecular structure, others less. When the absorbanceof water reaches the saturation point, residual water separates from the fluid forming free water.
Dissolved water in fluid is less harmfull than free water, since it is bound and has no reactivity. In case ofpressure or temperature fluctuations dissolved water can get undissolved leading to an enormouschange of fluid properties. The consequences of that are listed above. Strongly increased content of freewater in a fluid can be detected optically, since it is leading to a clouding of the fluid.
The water in a fluid can be measured by different methods. Traditionally, Karl-Fischer-titration is used,which is used to determine the total water content. ISO 760 describes this procedure in general.
Measuring the total water content means, there is no possibility to distinguish between the dissolved andundissolved water by using this method, making ppm values describing the water content often not
sufficient enough.
Examples for critical water content of different fluids:
Fluid type

Critical water content

Mineral oil (HLP)

200 ppm — 500 ppm

Mineral oil with D-additives (HVLPD)

600 ppm — 1200 ppm

Biodegradable oil (HEES)

700 ppm

Fire resistant fluid (HFC=Water in Glycol emulsion)> 4000 ppm

Universal Tractor Transition Oil (UTTO)

1000 ppm — 2000 ppm

C Caution
All numbers in this table are only rough guides, which strongly differ in dependency with the used baseoil, additive packages and the application of the hydraulic system.

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Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Fluid type-related standards and specifications
Mineral oil based hydraulic fluids according to specification:

•
•
•
•

DIN 51524-2: Mineral oil hydraulic fluids of category HLP
DIN 51524-3: Mineral oil hydraulic fluids of category HVLP
ISO 11158: Mineral oil hydraulic fluids of category HM
ISO 11158: Mineral oil hydraulic fluids of category HVEnvironmentally acceptable fluids according to specification ISO 15380 of category:

•
•
•
•

HEES (synthetic esters) meeting Annex B of ISO 15380 (shear stability test & yellow metal test)
HETG (tri-glycerides) meeting the same pour point specification as Category HEES and meeting
Annex B of ISO 15380 (shear stability test & yellow metal test)
HEPG (poly-glycols) meeting Annex B of ISO 15380 (shear stability test & yellow metal test)
HEPR (poly-alpha-olefins, PAO)

Automatic Transmission Fluids (ATF) according to OEM specification
In additional to the international standards there is a variety of OEM specifications for fluids.
To meet the basic requirements for fluids all of the below mentioned ATF fluids must additionally meetthe requirements of Table 3 in ISO 11158.
• GM ATF A Suffix A VI
• GM Dexron, which meets Allison C-4 and Caterpillar TO-4 test, downwards compatible with GM
Dextron II or III• Ford M2C33F and G• Mercon V, Mercon LV• ATF DW-1
• SP-IV or SP4• Matic S, Matic L, Matic D• ATF T-IV
• Toyota ATF-WS• Honda DW
Gear Oils
In additional to the international standards there is a variety of gear oil specifications for fluids, which aredescribed in ISO 12925-1. To meet the basic requirements for fluids both of the below mentioned gear
fluids must additionally meet the requirements of Table 3 in ISO 11158.
• API GL-4
• API GL-5
Engine Oils
In additional to the international standards there is a variety of engine oil specifications for fluids, which
are described in ISO 6743-15.
To meet the basic requirements for fluids all of the below mentioned engine oils must additionally meetthe requirements of Table 3 in ISO 11158.
• Engine oils API Classification CI-4, CH-4, CG-4, CF-4 and CF (for diesel engines), where the latest
category usually – but not always – includes the performance properties of an earlier category.
• Super Tractor Oil Universal (STOU), which meets the requirements up to API CF-4
• API GL4 with Limited- Slip (LS) additives
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Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
The following fluid classes meet the necessary requirements for the usage in hydrostatic units, but
significant changes of the lifetime can be present:• Premium Turbine Oils
• Tractor Oil Universal (TOU)• Fire resistant fluids HFA, HFB, HFC, and HFD are suitable at modified operating parameters, but notwith gear pumps and motors.
Contact the fluid manufacturer for more information about the suitability of a fluid in the expected
application.

Fluid cleanliness
The cleanliness of a fluid is one of the most important features to guarantee a satisfying performance ofthe hydraulic system. Contamination of a fluid with solid particles can lead to a failure of the complete
hydraulic system by locking of the pistons or blocking the valves. Different systems have different
sensitivity to solid contamination of the fluid, so different levels of fluid cleanliness are determined by ISO
4406. The determination of the cleanliness level is made by counting the particles, distinguishing theparticle size.
Further information to fluid cleanliness, filter compatibility in a system and the cleanliness levels can befound in the document Design Guidelines for Hydraulic Fluid Cleanliness, Technical Information,
BC00000095.
Fluid change intervals
Danfoss recommends the following fluid change intervals for all fluids except those mentioned below:• First change: 500 operating hours after start up•

Second and subsequent change every: 2000 operating hours or once a year

For HFA, HFB, HFC, HFD and biodegradable hydraulic fluids HETG shorter fluid change intervals arerecommended:• First change: 500 operating hours after start up•

Second and subsequent change every: 1000 operating hours or once a year

This recommendation applies for most applications. High temperatures and pressures will result inaccelerated fluid aging and an earlier fluid change may be required. At lower fluid pressure loads longer
change intervals are possible. Therefore we suggest taking a sample of the fluid at least one time,
preferably more, between scheduled fluid changes. This fluid sample then can be sent to the fluid
manufacturer or an appropriate laboratory for an analysis and a determination of its suitability forcontinued use.

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Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Traces of wear metals and contamination
Wear metals are the result of corrosive wear due to water and acids but also abrasive wear due to surface
roughness metal contact leading to welding. The table below shows typical amount of wear metals. In
some mobile applications for copper numbers up to 300 mg/kg and aluminum up to 80 mg/kg havebeen found.
These metal traces are determined by Atom–Emission–Spectroscopy (AES) according to ASTM D5185-97.
Typically particles smaller than 5 µm are detected. Larger particles are discussed below in the fluid
cleanliness requirements section.
These metal traces may increase during operation. It is therefore important to monitor the wear metal
concentration during operation. A sudden increase is an indication for a soon wear failure or that parts
have been already damaged.
Typical values for traces of wear metal in hydraulic systems (mg/kg)
Fe

Cr

Sn

Al

Ni

Cu

Pb

Mo

30

10

10

10

2

50

15

5

Silicium (Si) has the highest percentage in dust and is contamination in a system. Silicium is very abrasive
and a fluid change is recommended if 10–15 mg/kg are exceeded.

16 | © Danfoss | July 2016

520L0463 | BC00000093en-US0801

Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Viscosity and temperature limits
When using hydraulic fluid the viscosity and temperature limits in the table below are to be observed.
Under normal operating condition it is recommended to keep the temperature in the range of 30°C to
60°C.
Fluid temperature affects the viscosity of the fluid and resulting lubricity and film thickness. Hightemperatures can also limit seal life, as most nonmetallic materials are adversely affected by use atelevated temperatures.
Fluids may break down or oxidize at high temperatures, reducing their lubricity and resulting in reduced
life of the unit. As a rule of thumb, fluid temperature increase from 80 °C [176 °F] to 90 °C [194 °F] may
reduce fluid life by 50%.
Overview on viscosity and temperature limits
Product line

Min. vicosity(intermit.)
mm2/s [SUS]Max.
temperature(intermit.)oC [oF]

Recommended
viscosity
mm2/s [SUS]

Max. cold startviscosity
mm2/s [SUS]Min.
temperatureoC [oF]

H1B

5 [ 42.38]

115 [239]

12-80[66.03-370.3]

1600 [7406]-40 [-40]

Series 15
Open circuit

12 [66.03]

85 [185]860 [3981]-20 [-4]

Series 20

7 [48.79]

95 [203]

1000 [4629]-40 [-40]

105 [221]

1600 [7406]

H1P

Series 40
Series 42

115 [239]

Series 45

9 [55.51]

105 [221]

1000 [4629]

Series 51

7 [48.79]

115 [239]

1600 [7406]

Series 90

7 [48.79]

115 [239]-40 [-40]

TMP/TMM
LV/LC/KV/KC

105 [221]

Hydrostatic
steerings

10 [58.91]

Proportional
valves4 [39.17]

Electrohydraulicvalves12 [66.03]

Spool valves

6 [45.59]

Orbital motors

12 [66.03]*
20 [97.69]**

90 [194]

1000 [4629]-30 [-22]

460 [2129]
82 [180]

90 [194]440 [2037]

20-80[97.69-370.3]

1500 [6944]* For OMR, OMH, OMS, OMT, OMV, TMT** For OML, OMM, OMP

Fire resistant fluids HFA, HFB, HFC, and biodegradable fluids HETG have limited temperature capabilities.
Please see the individual fluids information given in this manual and contact the fluid manufacturer.
Viscosity – Temperature diagrams on page 18 shown on the next seven pages are for a reference only.
Please check actual viscosity with fluid manufacturer.
For more information to specific product lines please check the technical information to corresponding
product on the official http://www.powersolutions.danfoss.com website.

© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 17

Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Viscosity – Temperature diagrams
Hydraulic fluid according to DIN 51 524-2 HLP
2000000
1000000 -40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120 130 140 150

100000
70000
50000
30000
20000

ISO VG 100 (VI = 98)
ISO VG 68 (VI = 100)
ISO VG 46 (VI = 103)
ISO VG 32 (VI = 107)
ISO VG 22 (VI = 105)

10000
7000
5000
4000
3000
2000
1500

n max

1000
800
700
600
500
400
300

100 mm2 /s
90
80
70
60
50

Proportional valve

Spool valve

Series 15

Hydrostatic steering

20
18
16
14

Series 10,20

25

Series 45

30

Series 40, 42, 51, 90, CW5-8*

40

Series 60,LPM*

100
90
80
70
60
50

Gear Pumps + Motors

150

Cartridge + Electrohydraulic valve

200

Orbital motors OML, OMM, OMPintermittentcold start
Orbital motors OMR, OMH, OMS, OMT, OMV, TMT

Kinematic viscosity mm2/s

500000300000200000

40
30
25
20
18
16
14

Recommended
viscosity range
12-80 mm2/s
for all components
except for
OML, OMH + OMP
Orbital motors

12

12
11
10
9
8

10
9
8

nmin

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50 -45 -40 -35 -30 -25 -20 -15 -10 -5* hydrostatic motor only0

+5 10 15 20 25 30

40

50

60

70

80

90

100

110

120 130 140 150 160

Temperature oC
P002 051E

18 | © Danfoss | July 2016

520L0463 | BC00000093en-US0801

Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Hydraulic fluid according to DIN 51 524-3 HVLP
2000000

Kinematic viscosity

mm2/s

1000000

-40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

500000300000200000100000
70000
50000
30000
20000
10000

7000
5000
4000
3000

ISO VG 100 (VI = 170)
ISO VG 68 (VI = 180)
ISO VG 46 (VI = 180)
ISO VG 32 (VI = 165)

2000
1500

Spool valve

100 mm 2/s
90
80
70
60

Proportional valve

20
18
16

Series 10,20

25

Series 15

30

Series 45

40

Series 40, 42, 51, 90, CW5-8 *50

Gear Pumps + Motors

100
90
80
70
60

Series 60, LPM *150

Orbital motors OML, OMM, OMP

200

intermittentcold start

Cartridge + Electrohydraulic valve

300

Orbital motors OMR, OMH, OMS, OMT, OMV, TMT

n max

1000
800
700
600
500
400

50

Recommended
viscosity range
12-80 mm2/s
for all components
except for
OML, OMH + OMP
Orbital motors

40
30
25
20
18
16

14

14

12
11
10

12

9

10
9

n min

8

8

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50

-45

-40

-35

-30

-25 -20 -15 -10* hydrostatic motor only

-5

0

+5 10

15 20 25 30

40

50

60

70

80

90

100

110

120

130

Temperature140

150 160oC
P002 052E© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 19

Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Automatic Transmission Fluids (ATF) typ A, SUFFIX A (GM)
2000000
1000000 -40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120 130 140 150

100000
70000
50000
30000
20000
10000
7000
5000
4000
3000

TYP A, SUFFIX A (VI = 154)

2000
1500

n max

100 mm 2 /s
90
80
70
60
50

Proportional valve

Spool valve

Series 15

Hydrostatic steering

20
18
16
14

Series 10,20

25

Series 45

30

Series 40, 42, 51, 90, CW5-8*

40

Series 60,LPM*

100
90
80
70
60
50

Gear Pumps + Motors

150

Orbital motors OML, OMM, OMP

200

intermittentcold start

Cartridge + Electrohydraulic valve

1000
800
700
600
500
400
300

Orbital motors OMR, OMH, OMS, OMT, OMV, TMT

Kinematic viscosity mm2/s

500000300000200000Recommended
viscosity range
12 - 80 mm2/s
for all components
except for
OML, OMH + OMP
Orbital motors

40
30
25
20
18
16
14
12

12
11
10
9
8

10
9
8

n min

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50 -45 -40 -35 -30 -25 -20 -15 -10 -5* hydrostatic motor only0

+5 10 15 20 25 30

40

50

60

70

80

90

100

110

120 130 140 150 160

TemperatureoCP002 053E

20 | © Danfoss | July 2016

520L0463 | BC00000093en-US0801

Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Automatic Transmission Fluids (ATF) DEXRON II
2000000
1000000 -40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120 130 140 150

100000
70000
50000
30000
20000
10000
7000
5000
4000
3000

DEXRON II (VI = 166)

2000
1500

n max

100 mm2 /s
90
80
70
60
50

Proportional valve

Spool valve

Hydrostatic steering

Series 15

20
18
16
14

Series 10,20

25

Series 45

30

Series 40, 42, 51, 90, CW5-8*

40

Series 60,LPM*

100
90
80
70
60
50

Gear Pumps + Motors

150

Cartridge + Electrohydraulic valve

200

intermittentcold start

Orbital motors OML, OMM, OMP

1000
800
700
600
500
400
300

Orbital motors OMR, OMH, OMS, OMT, OMV, TMT

Kinematic viscosity mm2/s

500000300000200000Recommended
viscosity range
12-80 mm2/s
for all components
except for
OML, OMH + OMP
Orbital motors

40
30
25
20
18
16
14
12

12
11
10
9
8

10
9
8

n min

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50 -45 -40 -35 -30 -25 -20 -15 -10 -5* hydrostatic motor only0

+5 10 15 20 25 30

40

50

60

70

80

90

100

110

120 130 140 150 160

TemperatureoCP002 054E© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 21

Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Automatic Transmission Fluids (ATF) M2C33F/G, FORD
2000000
1000000 -40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120 130 140 150

100000
70000
50000
30000
20000
10000
7000
5000
4000
3000

M2C33F/G (VI = 185)

2000
1500

nmax

100 mm2 /s
90
80
70
60
50

Proportional valve

Spool valve

Series 15

Hydrostatic steering

20
18
16
14

Series 10,20

25

Series 45

30

Series 40, 42, 51, 90, CW5-8*

40

Series 60,LPM*

100
90
80
70
60
50

Gear Pumps + Motors

150

Cartridge + Electrohydraulic valve

200

intermittentcold start

Orbital motors OML, OMM, OMP

1000
800
700
600
500
400
300

Orbital motors OMR, OMH, OMS, OMT, OMV, TMT

Kinematic viscosity mm2/s

500000300000200000Recommended
viscosity range
12-80 mm2/s
for all components
except for
OML, OMH + OMP
Orbital motors

40
30
25
20
18
16
14
12

12
11
10
9
8

10
9
8

n min

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50 -45 -40 -35 -30 -25 -20 -15 -10 -5* hydrostatic motor only0

+5 10 15 20 25 30

40

50

60

70

80

90

100

110

120 130 140 150 160

TemperatureoCP002 056E

22 | © Danfoss | July 2016

520L0463 | BC00000093en-US0801

Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Engine oil per API classification CI-4, CH-4, CG-4, CF-4 and CF
2000000
1000000 -40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120 130 140 150

Kinematic viscosity mm2/s

500000300000200000100000
70000
50000
30000
20000

SAE 30(VI = 95)
SAE 15W-40 (VI = 140)
SAE 20W-20 (VI = 102)

10000
7000
5000
4000
3000
2000
1500

100 mm2 /s
90
80
70
60
50

Proportional valve

Spool valve

Cartridge + Electrohydraulic valve

Hydrostatic steering

Series 15

20
18
16
14

Series 10,20

25

Series 45

30

Series 40, 42, 51, 90, CW5-8*

40

Series 60,LPM*

100
90
80
70
60
50

Gear Pumps + Motors

150

intermittentcold start

Orbital motors OML, OMM, OMP

200

Orbital motors OMR, OMH, OMS, OMT, OMV, TMT

n max

1000
800
700
600
500
400
300

40
30
25
20
18
16
14

Recommended
viscosity range
12-80 mm2/s
for all components
except for
OML, OMH + OMP
Orbital motors

12

12
11
10
9
8

10
9
8

n min

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50 -45 -40 -35 -30 -25 -20 -15 -10 -5* hydrostatic motor only0

+5 10 15 20 25 30

40

50

60

70

80

90

100

110

120 130 140 150 160

Temperature oC
P002 057E© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 23

Technical Information
Hydraulic Fluids and LubricantsRequirements for Hydraulic Fluids
Multi Purpose Oil STOU - Super Tractor Oil Universal
2000000
1000000 -40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120 130 140 150

100000
70000
50000
30000
20000
10000
7000
5000
4000
3000

SAE 10W-30 (VI = 141)

2000
1500

n max

100 mm2 /s
90
80
70
60
50

Proportional valve

Spool valve

Series 15

Hydrostatic steering

20
18
16
14

Series 10,20

25

Series 45

30

Series 40, 42, 51, 90, CW5-8*

40

Series 60,LPM*

100
90
80
70
60
50

Gear Pumps + Motors

150

Cartridge + Electrohydraulic valve

200

intermittentcold start

Orbital motors OML, OMM, OMP

1000
800
700
600
500
400
300

Orbital motors OMR, OMH, OMS, OMT, OMV, TMT

Kinematic viscosity mm2/s

500000300000200000Recommended
viscosity range
12-80 mm2/s
for all components
except for
OML, OMH + OMP
Orbital motors

40
30
25
20
18
16
14
12

12
11
10
9
8

10
9
8

n min

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50 -45 -40 -35 -30 -25 -20 -15 -10 -5* hydrostatic motor only0

+5 10 15 20 25 30

40

50

60

70

80

90

100

110

120 130 140 150 160

TemperatureoCP002 058E

24 | © Danfoss | July 2016

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Technical Information
Hydraulic Fluids and Lubricants
Fire Resistant Hydraulic Fluids
HFA fluids – oil in water emulsions, according to ISO 12 922.
By application of this fluid type, some problems with bacterial control and corrosion could occur. Fluid
pH can become unstable and cause wear and chemical reaction with aluminum.
A positive head reservoir is required to maintain a positive inlet pressure when operating, and to keep air
out of internal passageways when shut down. HFA fluids are divided into two groups:
HFAE Oil-in-Water emulsions with low emulsion oil content according to ISO 12 922. Normally these
fluids contain 1 to 5% emulsion oil related to the volume.
HFAS Solutions with typically not more than 10% fluid concentrate in water according to ISO 12 922.

HFB fluids – water in oil emulsions, according to ISO 12 922.
These fluids can break down with repeated freezing and thawing. Also, heating above 60 °C [140 °F] cancause emulsion breakdown. High specific gravity requires an elevated reservoir and increased inlet line
size.
Monitoring of fluid water content is necessary. Frequent additions may be necessary in order toovercome evaporation losses. These fluids also show poor vapor phase corrosion inhibition.
HFC fluids – water polymers / water glycols, according to ISO 12 922.
They attack zinc and cadmium, and produces solvent action on some paints. For more information
contact the fluid manufacturer. Wear of aluminum in transmission parts sometimes occurs in thepresence of these fluids.
Viton seals are not recommended. High specific gravity requires an elevated reservoir and increased inlet
line size.
Water content and pH-number may be a problem.
HFD fluids – water free, synthetic fluids according to ISO 12 922.
Viton seals are required. Consult the fluid manufacturer to obtain a recommendation of the particular
fluid used. These fluids attack some plastics, zinc and cadmium. High specific gravity requires an elevatedreservoir and increased inlet line size. HFD fluids are divided into four groups:
HFDR Fluid based on Phosphorus acid Ester according to ISO 12 922. Used primarily in Great Britain in
the mining industry.
HFDS Fluid based on Chlorinated Hydrocarbons. Used primarily in hydrodynamic clutches.
HFDT Fluid based on mixtures of Phosphorus acid Ester and Chlorinated Hydrocarbons. Used primarily
in hydrostatic transmissions.
HFDU Other synthetic hydraulic fluids without water according to ISO 12 922. Used primarily inaviation hydrostatic.
Some of these fluids have caused high wear of aluminum parts in transmissions.
Fluid conversion
Consult ISO 7745 and the fluid manufacturer guidelines when converting to another hydraulic fluid. Usecaution when converting an application to a different fluid. Thoroughly test the new fluid in theapplication before committing to the change.

© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 25

Technical Information
Hydraulic Fluids and Lubricants
Fire Resistant Hydraulic Fluids
General operating parameters for fire resistant hydraulic fluids
Danfoss hydrostatic products, except gear pumps and gear motors, may be used with fire resistant fluids
under modified operating parameters as listed below.
In any case when ordering Danfoss products, please make sure you specify the desired fluid to be used.
The appropriate seals or other modification will then be provided.
Operating parameters for fire resistant hydraulic fluids according to ISO 12 922
Type of fluid

HFA
Oil in water
emulsion

HFB
Water in oil
emulsion

HFC
Watery polymer
solution

HFD
Water free synthetic

Operatingtemperature*

5 – 55 °C[40 – 130 °F]

5 – 60 °C[40 – 140 °F]-20 – 60 °C[-4 – 140 °F]

10 – 70 °C[50 – 160 °F]

Water content*

> 80%

> 40%

> 35%

–

Typical roller
bearing life**< 5%30 – 35%

10 – 20%

50 – 100%* The temperature range and the water content are based on the specific fluid properties.
** Mineral based fluid is 100%.

26 | © Danfoss | July 2016

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Technical Information
Hydraulic Fluids and Lubricants
Fire Resistant Hydraulic Fluids
Specific operating parameters for products running with fire resistant fluids
The specific operating parameters are based on the technical data shown in the Technical Information foreach product. Fluid change intervals are modified as shown earlier in fluid change interval section.
Axial piston pumps and bent axis motors
Type of fluid

HFA

HFB

HFC

HFD

Speed

65%

65%

65%

100%

Differential pressure

40%

70%

60%

100%

Inlet pressure (bar abs. [in Hg])

1 [0]0.95 [1.5]0.95 [1.5]0.95 [1.5]Orbital motors
Type of fluid
OMM, OMPMax.
differential
pressure*bar [psi]

OMR

OMS, OMT,OMVEstimated life time(mineral based fluid is 100%)

HFA

HFB

HFC

HFD

cont.

50 [725]70 [1015]

70 [1015]

70 [1015]

interm.

70 [1015]

100 [1450]

100 [1450]

100 [1450]

cont.

70 [1015]

100 [1450]

100 [1450]

100 [1450]

interm.

100 [1450]

140 [2031]

140 [2031]

170 [2466]

cont.

100 [1450]

140 [2031]

140 [2031]

170 [2466]

interm.

140 [2031]
2 - 5%

175 [2538]
10 - 20%175 [2538]
10 - 15%210 [3046]
80 - 100%* The above mentioned recommendations for maximum temperature limits are a guideline for most of applications.

Proportional valvesFire resistant fluids may be used, but much lower lifetime, compared to mineral oil, may be expected.
Low viscosity and high pressure may increase the internal leakage. Increasing internal leakage may cause
erosion because of the higher fluid velocity. The wear caused by erosion is worsened if the fluid iscontaminated.
The density and steam pressure for fire resistant fluids are different from mineral oils, and this may
increase the risk of cavitation. Also the pressure drop is different, and this may influence the dynamics
and stability of the valve. Therefore it is recommended to minimize pressure drop and keep working
temperatures low.
Steering units
HFA, HFB, HFC and HFD-U fluids may be used, but much lower lifetime, compared to mineral oil, may be
expected. Steering units may not operate with HFD-R fluids (phosphate ester).

© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 27

Technical Information
Hydraulic Fluids and Lubricants
Biodegradable Hydraulic Fluids
Biodegradable hydraulic fluids according to ISO 15 380
The growing environmental awareness has increased the research and development for biodegradable
hydraulic fluids. Although these fluids have improved over the last years these are not yet ready toreplace mineral based hydraulic fluids. Still several performance issues need to be improved.
The minimum technical requirements for biodegradable hydraulic fluids are specified in the German
standard VDMA 24 568 – Rapidly Biologically Degradable Hydraulic Fluids Minimum TechnicalRequirements
The ISO 15380 - lubricants, industrial oils and related products (class L) – family H (Hydraulic systems) –describes the fluid categories HETG, HEPG, HEES and HEPR providing guidance for suppliers and users ofenvironmentally acceptable hydraulic fluids, and to advice manufacturers of hydraulic systems. This norm
also stipulates the requirements for environmentally acceptable hydraulic fluids at the time of delivery.

W Warning
To avoid damage caused by the hydraulic fluid we recommend to take fluid samples every 150 – 200
operating hours. The fluid manufacturer should check the further fluid usability.
All biodegradable hydraulic fluids are subject to special disposal regulations similar to mineral based
hydraulic fluids. The legal national and international ordinances and regulations will apply. Particularly
the instructions of the fluid manufacturer must be followed.
Many fluid manufacturers voluntarily offer to take back the used fluids.

28 | © Danfoss | July 2016

520L0463 | BC00000093en-US0801

Technical Information
Hydraulic Fluids and Lubricants
Biodegradable Hydraulic Fluids
HETG - Triglyceride hydraulic fluids
Features:• very good viscosity-temperature behavior

•
•
•
•
•
•
•

high biological degradability
water hazard class WGK 0
good corrosion protection
good compatibility with seals/gaskets
density approximately 0.92 g/ml
pour point approximately -10 °C to -25 °C [-50 to -77 °F].
(The fluid may become solid after extended storage at low temperatures. For further questions pleasecontact the fluid manufacturer.)
the minimum requirements of ISO 15 380 are generally met.

Operating data:
Under consideration of the HETG fluid properties the temperature range, however, is limited to -15 °C to
70 °C [-59 °F to 158 °F].
In order to avoid accelerated aging of the fluid , tank temperatures above 60 °C [140 °F] should be
avoided.

W Warning
All hydraulic components are tested with mineral oil!
All housings must be drained completely before installation to avoid mixing of fluid types!
Change interval:
Fluid change intervals are modified as shown earlier in fluid change interval section.
Hints for transition:
ISO 15 380 and the appropriate guidelines of each individual hydraulic fluid manufacturer are applicable.
The remaining max residual volume as specified in ISO 15 380 must not be exceeded.
Requirements for biodegradable hydraulic fluids HETG:
The requirements concerning water content, Viscosity–Temperature limits, cleanliness level, which aredescribed in the section Requirements for Hydraulic Fluids on page 14 must be met in addition to above
mentioned requirements, especially the needed temperature limitations to prevent rapid fluid ageing.

© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 29

Technical Information
Hydraulic Fluids and Lubricants
Biodegradable Hydraulic Fluids
HEPG – Polyglycol hydraulic fluids
Features:• very good viscosity-temperature behavior

•
•
•
•
•
•
•

biologically degradable
water hazard class WGK 0
good corrosion protection
partially unacceptable compatibility with seals/gaskets
density > 1.0 g/ml
pour point approximately -10 °C to -25 °C [-50 to -77 °F]
the minimum requirements of ISO 15 380 are generally met.

Operating data:
Due to the higher density compared to mineral oil the permissible suction pressure must be strictly
adhered to.

W Warning
All hydraulic components are tested with mineral oil!
All housings must be drained completely before installation to avoid mixing of fluid types!
Hints for transition:
Based on a few particular characteristics of poly glycol based fluids, as for example,
partially unacceptable paint incompatibility•••

low seal/gasket compatibility
no mixability with mineral oil

The exchange of fluids in existing installation may be very expensive. ISO 15 380, and the appropriate
guidelines of each individual hydraulic fluid manufacturer are applicable. The remaining max residual
volume as specified in ISO 15 380 must not be exceeded.
Requirements for biodegradable hydraulic fluids HEPG:The requirements concerning water content, Viscosity–Temperature limits, cleanliness level, which aredescribed in the section Requirements for Hydraulic Fluids on page 14 must be met in addition to above
mentioned requirements.

30 | © Danfoss | July 2016

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Technical Information
Hydraulic Fluids and Lubricants
Biodegradable Hydraulic Fluids
HEES – Synthetic ester based hydraulic fluids
Features:• very good viscosity-temperature behavior

•
•
•
•
•
•
•
•
•

biologically well degradable
water hazard class WGK 0
good corrosion protection
good compatibility with seals/gaskets
good lubricating characteristics
good aging resistancedensity approximately 0.92 g/ml
pour point approximately -10 °C to -25 °C [-50 to -77 °F]
the minimum requirements of ISO 15 380 are generally met.

Operating data:
Due to the higher density compared to mineral oil the permissible suction pressure must be strictly
adhered to.

W Warning
All hydraulic components are tested with mineral oil!
All housings must be drained completely before installation to avoid mixing of fluid types!
Hints for transition:
ISO 15 380, and the appropriate guidelines of each individual hydraulic fluid manufacturer are applicable.
The remaining max residual volume as specified in ISO 15 380 must not be exceeded.
Requirements for biodegradable hydraulic fluids HEES:The requirements concerning water content, Viscosity–Temperature limits, cleanliness level, which aredescribed in the section Requirements for Hydraulic Fluids on page 14 must be met in addition to above
mentioned requirements, especially the needed temperature limitations to prevent rapid fluid ageing.

© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 31

Technical Information
Hydraulic Fluids and Lubricants
Biodegradable Hydraulic Fluids
HEPR – Polyalphaolefins and related hydrocarbon hydraulic fluids
Features:• very good viscosity–temperature behavior

•
•
•
•
•
•
•
•
•

reduced biologically degradability, especially at higher viscosities
water hazard class WGK 1 – 2
good corrosion protection
may be incompatible with some seals/gaskets, it is recommended to check seal compatibility
individually
good lubricating characteristics
good aging resistancedensity approximately 0.86 g/ml
pour point approximately -20 °C to -40 °C [-68 to -104 °F]
the minimum requirements of ISO 15 380 are generally met.

Operating data:
Due to the higher density compared to mineral oil the permissible suction pressure must be strictly
adhered to.

W Warning
All hydraulic components are tested with mineral oil!
All housings must be drained completely before installation to avoid mixing of fluid types!
Hints for transition:
ISO 15 380, and the appropriate guidelines of each individual hydraulic fluid manufacturer are applicable.
The remaining max residual volume as specified in ISO 15 380 must not be exceeded.
Requirements for biodegradable hydraulic fluids HEPR:
The requirements concerning water content, Viscosity–Temperature limits, cleanliness level, which aredescribed in the section Requirements for Hydraulic Fluids must be met in addition to above mentioned
requirements.

32 | © Danfoss | July 2016

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Technical Information
Hydraulic Fluids and Lubricants
Biodegradable Hydraulic Fluids
Viscosity – Temperature Diagram
2000000
1000000 -40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120 130 140 150

100000
70000
50000
30000
20000

ISO VG 100 (VI = 98)
ISO VG 68 (VI = 100)
ISO VG 46 (VI = 103)
ISO VG 32 (VI = 107)
ISO VG 22 (VI = 105)

10000
7000
5000
4000
3000
2000
1500

n max

100 mm2 /s
90
80
70
60
50

Proportional valve

Spool valve

Hydrostatic steering

Series 15

20
18
16
14

Series 10,20

25

Series 45

30

Series 40, 42, 51, 90, CW5-8*

40

Series 60,LPM*

100
90
80
70
60
50

Gear Pumps + Motors

150

Biodegradable
Hydraulic Fluid
Cartridge + Electrohydraulic valve

200

intermittentcold start

ISO VG 32 (VI = 200)

Orbital motors OML, OMM, OMP

1000
800
700
600
500
400
300

Orbital motors OMR, OMH, OMS, OMT, OMV, TMT

Kinematic viscosity mm2/s

500000300000200000

12
11
10
9
8

40
30
25
20
18
16
14
12
10
9
8

n min

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50 -45 -40 -35 -30 -25 -20 -15 -10 -5*hydrostatic motor only0

+5 10 15 20 25 30

Recommended
viscosity range
12 - 80 mm2/s
for all components
except for
OML, OMH + OMP
Orbital motors

40

50

60

70

80

90

100

110

120 130 140 150 160

Temperature oC
P001 678E

Shown viscosity characteristics are for reference only. Please check actual viscosity with fluid
manufacturer.
© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 33

Technical Information
Hydraulic Fluids and LubricantsGear Lubricants
Features
Gear lubricants have to perform the following tasks:• Lubrication•

Heat removal

When choosing a gear lubricant the following features are most important for consideration:
Viscosity••••

Temperature sensitivity or viscosity Index (VI)
Pour point
Anti-wear or extreme pressure capabilities

For any particular application the features of the lubricant must be appropriate to the operating
conditions of the unit and the regulations of the manufacturer.
For explanation of the terms Viscosity, Viscosity Index (VI) and Pour point see section Hydraulic fluids.
Gear lubricants specifications
The lubricants are to be chosen together with the gear manufacturer for each application. Danfoss
gearboxes may be operated with a variety of lubricants.
The following gear lubricants meet the basic requirements for application in Danfoss components:• Lubricant DIN 51 517, part 3 - CLP••

34 | © Danfoss | July 2016

Lubricant API-Classification GL4 or MIL-L-2105
Lubricant API-Classification GL5 or MIL-L-2005

520L0463 | BC00000093en-US0801

Technical Information
Hydraulic Fluids and LubricantsGear Lubricants
Example for selecting the kinematic viscosity - transit mixer drive (agitate mode)
Nomograph for selection of kinematic viscosity for gear lubricantsGear Ratio
1000 500

i ges
200 100 50 30

10 5

3

5
Viscosity

mm2/s

190 180 170

140 120[SUS][879.5] [786.9] [648.1]

100

60

30

[277.9][141.2]80[462.9][833.3]

4

Artificial line A
Output speed • n2

min-1 (rpm)1

2 3 45

10

50

20

150

200300 500 1000 2000

2

1
Continuous power • P

kW [hp]1[1.34]

2 3 4 520
10[13.4] [26.8]

50 100 200[67] [134]500 1000

3000
P000 599E

Assumed:1 Power: 15 kW [20 hp]
2 Output speed: 4 min-1 (rpm)
3 Gear ratio:i = 99 and Temperature: 55 °C [131 °F]
Nomograph:
5 Required viscosity at operating temperature: 180 mm2/s [833.3 SUS]
Viscosity–temperature diagram - required lubricant: CLP 460

W Warning
Determination of the viscosity is only a reference value.
If the viscosity is between two different ISO viscosity grades, use the closests grade. For transit mixer
boxes EP-Gear lubricants according to API-Classification GL-5 should always be selected.
Normally gear lubricants with SAE viscosity grade 90 show sufficient performance. At higher
temperatures it is advisable to use Gear Lubricants with the SAE viscosity grade 140.
© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 35

Technical Information
Hydraulic Fluids and LubricantsGear Lubricants
Viscosity – Temperature diagrams
Lubricants according to DIN 51 517-3 - CLP
2000000
1000000

-40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

CLP 460 (VI = 97)
CLP 220 (VI = 98)
CLP 68 (VI = 101)

100000
70000
50000

n max

30000
20000

intermittentcold start

10000

7000
5000
4000
3000

50

100 mm 2/s
90
80
70
60
50

40

40

100
90
80
70
60

30

30

25

25

20
18
16

20
18
16

n min

14

14

12
11
10

12

9

9

Series PVG

Series CW/CT

150

Series PVG

200

Series RMF

300

Series TMG/LPM

1000
800
700
600
500
400

Series TMG/LPM

2000
1500

Series RMF/CW/CT

Kinematic viscosity mm2/s

500000300000200000Recommended
viscosity range

10

8

8

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50

-45

-40

-35

-30

-25 -20 -15 -10

-5

0

+5 10

15 20 25 30

40

50

60

70

80

90

100

110

120

Temperature

130
o

140

150 160

C
P002 060E

36 | © Danfoss | July 2016

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Technical Information
Hydraulic Fluids and LubricantsGear Lubricants
Lubricants according to SAE API GL 4, MIL-L-2105, API GL5, MIL-2105 B
2000000
1000000

-40

-30

-20

-10

0

10

20

30

40

50

SAE 140
SAE 85W-90
SAE 80W

100000
70000
50000

60

70

80

90

100

110

120

130

140

150

(VI = 92)
(VI = 97)
(VI = 104)
n max

30000
20000

intermittentcold start

10000

7000
5000
4000
3000

50

100 mm 2/s
90
80
70
60
50

40

40

100
90
80
70
60

30

30

25

25

20
18
16

20
18
16

n min

14

14

12
11
10

12

9

9

Series PVG

Series CW/CT

150

Series PVG

200

Series RMF

300

Series TMG/LPM

1000
800
700
600
500
400

Series TMG/LPM

2000
1500

Series RMF/CW/CT

Kinematic viscosity mm2/s

500000300000200000Recommended
viscosity range

10

8

8

7

7

6

6

5

5

4,5

4,5

4,0

4

3,5

3,5

3,0

3

2,7
-50

-45

-40

-35

-30

-25 -20 -15 -10

-5

0

+5 10

15 20 25 30

40

50

60

70

80

90

100

110

120

Temperature

130
o

140

150 160

C
P002 059E© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 37

Technical Information
Hydraulic Fluids and LubricantsGear Bearing Grease
Features
Gear bearing grease has to perform the following task – Lubrication. Roller bearing grease does not flowout of the bearing housing. The free space of a roller bearing can be filled well due to the plastic, easily
deformable structure. The filled grease quantity lubricates for a long period of time, as the required
lubricant remains in the bearing.
Roller bearing greases serve to reduce friction wear and temperature and protect against corrosion.
Bearing grease seals against external influences such as dust and humidity.
The high durability of a gear bearing grease avoids damage and machinery breakdown and increase thelife of the gears. High-grade bearing grease has a wide range of uses. It distinguishes itself by constanttemperatures, being waterproof and work endurance consistency. Furthermore, grease has a goodoxidation stability and excellent corrosion protection.
Even at low temperatures the greases listed in the table are still easily transportable and render an easy
bearing start-up possible.
Dropping point (ISO 2176)
The dropping point of a bearing grease is the temperature at which the first drop of grease brought tomelting falls from an ISO 2176 standardized test unit. The dropping point of grease must always be above
the intended bearing temperature.
Miscibility of gear bearing grease
Mixing of different soapanification agents is to be avoided. To be checked by grease manufacturer if
desired. Such mixtures are often the cause of damage due to “liquefaction” or “hardening” of the grease
mixture. When adjusting or even renewing the grease, remove the “old” grease completely.
Storage of gear bearing grease
Store grease in a dry area, if possible indoor. Buckets, large canisters or barrels are to be sealed with thelid immediately after use.
Consistency
The consistency index NGLI grade per ISO 6743-9 indicates how firm or soft a grease is. The following
table provides a good survey:
Bearing grease, worked penetration
Consistency index NGLI

38 | © Danfoss | July 2016

Consistency

Application in equipment000

very high flowability

yes, central lubrication

00

high flowability

yes, gear-flowable grease0

flowableyes, gear-flowable grease

1very soft

seldom2

soft

yes, multipurpose grease3

still soft

higher temperature4

medium firm

no

5

firm

no

6

very firmno520L0463 | BC00000093en-US0801

Technical Information
Hydraulic Fluids and Lubricants
Preservation fluids and petroleum jelly
Features of preservation fluids
For longer periods of storage and shut down corrosion protection is necessary. Preservation fluids
guarantee long-lasting protection against corrosion for hydrostatic transmissions and gears. In order toavoid corrosion which can result in shorter life and often high repair costs, corrosion protection is
generally provided for in the following applications:• For the dispatch of newly produced transmissions and gears and for longer time of transport,
especially at sea.
• For the shutdown of transmissions and gears used periodically in vehicles, processing machines andsystems (e. g. harvesters, construction machines, sugar refineries).
• For the dispatch of used vehicles and processing machines, e. g. to construction sites abroad.
Preservation fluids should be completely neutral as compared with hydraulic fluids or gear lubricants andother lubricants. In some cases compatibility testing between lubricating fluid and preservation fluid isrequired. When putting a machine into operation preservation fluid has to be drained. Additional
cleaning should not be necessary. Contact distributors of hydraulic fluid and/or lubricant.

W Warning
Mixing of fluids of different brands is not allowed.
The effort necessary for preservation depends on the length of shutdown or type of transport and theprevailing environmental conditions. Taking these factors into consideration, the following listed
preservation measures are recommended:• When filling transmissions and gears with hydraulic fluid, gear lubricant or preservation fluid use
recommended fluid in respect to the environmental conditions of the operation in question(viscosity).
Whenreoperating, drain preservation fluid and refill recommended fluid in respect to the•environmental conditions of the operation in question.
Transport typeFor dispatch of newly produced transmissions. Transport by rail or truck.
For dispatch of newly produced transmissions. Sea transport.
For shutdown of transmissions and gears used periodically in vehicles, processmachines.

Shutdown period
e.g. transport timeCode*

up to 6 monthA, E, G

up to 12 monthA, F, G

up to 3 monthA, F, G

up to 12 monthC, F, G

up to 6 month

B, E, G

up to 12 month

B, F, GFor dispatch of gears and transmissions used in vehicles or process machines.
Transport by rail or truck.

up to 6 month

B, E, G

up to 12 month

B, F, GFor dispatch of gears and transmissions used in vehicles or process machines.
Sea transport.

up to 3 month

B, F, G

up to 6 monthD, F, G

* For furter details about codes see the table below.

© Danfoss | July 2016

Code

Preservation measureA

Fill component with recommended hydraulic fluid or gear lubricant.

B

Change to recommended hydraulic fluid or gear lubricant.

C

Fill component or gear with recommended preservation fluid.

D

Change to recommended preservation fluid.

E

Grease piston rod when erected.

F

Preserve piston rod with long duration wax corrosion protection. Wrap air breather of transmissions andgears with strong plastic foil.

G

Install or change to new filters and/or air breathers.

520L0463 | BC00000093en-US0801 | 39

Technical Information
Hydraulic Fluids and Lubricants
Preservation fluids and petroleum jelly
Features and application of petroleum jelly
Petroleum jelly is used for assembly assistance and should be dissolved in the hydraulic fluid during
operation of the hydrostatic unit. To ensure this, the application operating temperature should be above
freezing point of the jelly (contact lubricants manufacturer).
Locking nozzles and throttle areas can therefore be avoided. Nevertheless, avoid overflow of thepetroleum jelly between surfaces during assembly.
The mentioned petroleum jelly is used for adhering O-rings and seals when mounting hydrostatictransmissions and gears so that they are fixed securely to the housing surfaces and in the annulargrooves and recesses.

40 | © Danfoss | July 2016

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Technical Information
Hydraulic Fluids and Lubricants© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 41

Technical Information
Hydraulic Fluids and Lubricants

42 | © Danfoss | July 2016

520L0463 | BC00000093en-US0801

Technical Information
Hydraulic Fluids and Lubricants© Danfoss | July 2016

520L0463 | BC00000093en-US0801 | 43

Products we offer:

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

Bent Axis Motors
Closed Circuit Axial Piston
Pumps and Motors
Displays
Electrohydraulic Power
Steering
Electrohydraulics

Danfoss Power Solutions is a global manufacturer and supplier of high-quality hydraulic andelectronic components. We specialize in providing state-of-the-art technology and solutions
that excel in the harsh operating conditions of the mobile off-highway market. Building on
our extensive applications expertise, we work closely with our customers to ensure
exceptional performance for a broad range of off-highway vehicles.
We help OEMs around the world speed up system development, reduce costs and bringvehicles to market faster.
Danfoss – Your Strongest Partner in Mobile Hydraulics.

Hydraulic Power Steering

Go to www.powersolutions.danfoss.com for further product information.

Integrated Systems

Wherever off-highway vehicles are at work, so is Danfoss. We offer expert worldwide support
for our customers, ensuring the best possible solutions for outstanding performance. And
with an extensive network of Global Service Partners, we also provide comprehensive global
service for all of our components.

Joysticks and Control
Handles
Microcontrollers andSoftwareOpen Circuit Axial Piston
Pumps
Orbital Motors

Please contact the Danfoss Power Solution representative nearest you.

PLUS+1® GUIDE
Proportional Valves
Sensors
Steering
Transit Mixer Drives

Comatrolwww.comatrol.com
Schwarzmüller-Inverterwww.schwarzmuellerinverter.com

Local address:

Turollawww.turollaocg.com
Hydro-Gear
www.hydro-gear.com
Daikin-Sauer-Danfoss
www.daikin-sauer-danfoss.com

Danfoss
Power Solutions (US) Company
2800 East 13th Street
Ames, IA 50010, USA
Phone: +1 515 239 6000

Danfoss
Power Solutions GmbH & Co. OHG
Krokamp 35
D-24539 Neumünster, Germany
Phone: +49 4321 871 0

Danfoss
Power Solutions ApS
Nordborgvej 81
DK-6430 Nordborg, Denmark
Phone: +45 7488 2222

Danfoss
Power Solutions Trading(Shanghai) Co., Ltd.
Building #22, No. 1000 Jin Hai Rd
Jin Qiao, Pudong New District
Shanghai, China 201206
Phone: +86 21 3418 5200

Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products
already on order provided that such alterations can be made without changes being necessary in specifications already agreed.
All trademarks in this material are property of the respective companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.

© Danfoss | July 2016

520L0463 | BC00000093en-US0801