OKS lubricants – highest performance for maximum process reliability

DN factor

The DN factor or rotating speed factor is a guide value up to which rotating speeds lubricants can be used in roller bearings.

FZG torque change test device

With the FZG torque change test device oils and greases are examined in particular with regard to their suitability as lubricants in closed gears. The wear is determined after every load level and the so-called “damage load level” specified as the result. The test method is described in DIN 51 354.

Lubrimeter test

The Lubrimeter test is a test device with which the coefficient of friction, wear and operating temperature of lubricants is measured for a specific period at changing loads and sliding speeds with different materials.

Oil separation

The oil separation is measured to DIN 51 817 as a % by weight. In the process pressure and temperature is applied to the lubricating grease to be tested.

Resistance to oxidation

The resistance to oxidation is a measure for the resistance against reactions with pure oxygen. According to DIN 51 808 the grease is subjected to increased pressure together with the oxygen for a specific period (e.g. 100 hours) and temperature (e.g. +99 °C or +160 °C). The test result is the drop in pressure of the oxygen in Pa (Pascal) as a measure for the degree of oxidation.

Layer thickness (corrosion protection)

The layer thickness has a decisive influence on the duration of the corrosion protection. To this purpose various measuring methods are used which specify the layer thickness in μm, depending on the type of protective layer.

Evaporation loss

The evaporation loss is of interest particularly at high-temperature lubricants. According to DIN 58 397 it is examined at high temperatures for a specified period. The loss of evaporated oil as a % by weight should be as low as possible.


Chemical changes to material through the influence of heat, light and oxygen across the operating time


Deutscher Verein des Gas- und Wasserfaches (German Technical and Scientific Association for Gas and Water)

EP additives

Lubricants with Extreme Pressure additives in order increase the pressure resistance and the wear protection properties


International Standardization Organisation


Reaction of a metal with its environment which results in a change and impairment of the function of a component


Approval for plastics in the drinking water sector


Landesgewerbeanstalt Nürnberg with its institute for food chemistry


Liquids that dissolve other materials without chemical changes

Emergency lubrication

Is achieved through solid lubricants when insufficient lubrication occurs at grease or oil lubricants

Frictional corrosion

Corrosion that occurs at fits that are subjected to vibrations with micro frictional movements. Immediate rust formation at abrasive particles of steel


Occurs at slow movements and insufficient separating effect of the lubricant, since the initial friction is higher than the movement friction

Silicone oils

Are produced through synthetic processes. They have particularly good viscosity temperature characteristics, are resistant at low and high temperatures and against ageing. Excellent separating properties. Outstanding lubricant for plastics and elastomers. Designations such as polydimethylsiloxane or polyphenylmethylsiloxane specify the special structure of the molecule groups

Synthetic oils

Produced through chemical processes in contrast to oils from Nature – mineral oils, vegetable oils and animal oils. Allowing certain advantages to be achieved, such as low tendency to coking, low pour point, good resistance to chemicals and often excellent viscosity temperature characteristics. Synthetic hydrocarbons, ester, polyglycols, fluorinated oils and silicone oils are used e.g. for lubricants


Volatile Corrosion Inhibitor is an environmentally friendly
corrosion protection additive


Arises when the lubricating film is breached, so that the sliding partners come into contact and rub against each other

White oil

Paraffinic mineral oil, highly refined, to remove instable components. White oils are used, for example, in lubricants for medical applications


Standard/ applicable to Title Keyword/
Meas. unit
 Conditions Description

DIN 51 502

Oils, greases

Lubricants and related substances; designation of lubricants and marking of lubricant containers, equipment and lubricating points. DIN designation of lubricants   Consistent and unambiguous marking of industrial lubricants based on corresponding test standards to avoid damage caused by mistaken use of inappropriate lubricants.

DIN 51 506

Compressor and condenser oils

VB and VC lubricating oils with and without additives and VDL lubricating oils Condenser oil requirements   Requirements for lubricating oils that are used in air condensers with oil-lubricated compression chambers with no injection cooling.

DIN 51 509

Gear oils
and greases

Selection of lubricants for gears
Part 1: Lubricating oils ("C")
Part 2: Plastic lubricants ("G" and "OG")
Requirements for gear oils and greases   Standard values, criteria and advice for the selection of lubricants for rolling gear (e.g. spur wheel or bevel gear with no axial offset) and screw rolling gear (e.g. worm gear).

DIN 51 517

Machine and gear oils

Lubricants; Lubricating oils
Part 1: Minimum requirements lubricating oils "C"
Part 2: Minimum requirements lubricating oils "CL"
Part 3: Minimum requirements lubricating oils "CLP"
Machine and gear oil requirements   Requirements for lubricating oils used for circulation and immersion lubrication

DIN 51 519


Lubricants; ISO viscosity classification for industrial liquid lubricants ISO VG- Klassen/
ISO VG- Klasse
Viscosity measured at
40 °C as defined in DIN 51 562-1 or DIN EN ISO 3104
Classification system for industrial liquid lubricants based on viscosity of the lubricant. The tolerance zone is determined to +/-10% nominal viscosity.

DIN 51 524

Hydraulic oils

Pressure fluids; Hydraulic oils
Part 1: Minimum requirements lubricating oils "HL"
Part 2: Minimum requirements lubricating oils "HLP"
Part 3: Minimum requirements lubricating oils "HVLP"
Hydraulic oil requirements   Requirements for hydraulic oils
DIN 51 825 lubricants; Lubricating greases K, Classification and requirements Roller and plain bearing grease requirements   Requirements for greases used to lubricate roller bearings, plain bearings and sliding surfaces.
DIN 51 836 lubricants; Lubricating greases G, Classification and requirements Gear transmission grease requirements   Requirements for greases used to lubricate enclosed gears.

DIN ISO 2909


Petroleum products; Calculation of viscosity index from kinematic viscosity Viscosity index/
Viscosity measured at
40 °C and 100 °C as defined in DIN 51 562-1 or DIN EN ISO 3104
The viscosity index (VI) describes the change in kinematic viscosity of an oil with temperature. Two different methods are used in relation to the calculation of viscosity index (A: VI < 100, B: VI > 100).
DIN ISO 6743-0 Lubricants, industrial oils and related products (class L); Classification; General ISO marking of lubricants   Adoption of the international standard ISO 6743 as a German DIN standard. Alternative marking system for industrial lubricants for the avoidance of damage by mistaken use of incorrect lubricant.

Roller bearing greases

DN value
/mm min
  Characteristic value that describes the maximum operating speed for rolling bearing greases
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  • Tribology Basic Knowledge

    Tribology Basic Knowledge

    Fundamentals about lubricants and tribology