Mechanical Tests

applicable to


Meas. unit



DIN 267-27

Screw pastes

Break away torque

x Tightening torque

M 10 A2/40 Nm/400 °C/100 h
(OKS Standard)

Ratio of break away torque required to release a screw connection compared to starting torque. Often following high temperature loading.

DIN 51 350

Oils, greases, pastes

Testing of lubricants; testing in the Shell-four-ball tester
Part 1: General working principles
Part 2: Determination of welding load of fluid lubricants
Part 3: Determination of welding load of fluid lubricants
Part 4: Determination of welding load of consistent lubricants
Part 5: Determination of wear characteristics for consistent lubricants

VKA test/
welding load: N
wear: mm

Welding Load: 1420 rpm
Wear (oils): 1420 rpm, 1 h, 150 N (Method A) or 300 N (Method B)
Wear (greases): 1420 rpm, 1 h, 150 N (Method C), 300 N (Method D) oder 1000 N (Method E)

Determination of characteristic values for lubricants that are suitable for use where high surface pressures occur in the mixed-friction zone between surfaces that move relatively to each other. The test makes use of a rotating ball, pressed against three identical, stationary balls. Measurements can be made of the force required to produce welding between the balls (welding load) or of the amount of wear on the balls after application of a defined force over a defined time.

DIN 51 354-2

Oils, fluid greases

FZG damage loading step

Load stage

A, 8,3/90
A2, 76/50

Testing of the load capacity of gear lubricants.

DIN 51 354-2

Oils, fluid greases

FZG wear


A, 8,3/90
A2 76/50

Testing of the load capacity of gear lubricants.

DIN 51 806

Roller bearing greases

SKF R2F Operting Test A
SKF R2F Operting Test B


2500 rpm, 20 d
1500 rpm, 20 d, 120 °C

Determination of lubricating properties of rolling bearing greases at room temperature (Operating Test A) and at a defined temperature (Operating Test B).

DIN 51 807-1

Greases (pastes)

Testing of lubricating greases in the presence of water, static test

Water resistance/
Evaluation class 0 to 3 at stated test temperature

Specified temperature (usually 90 °C), distilled water, 3 h test duration

A 1 mm thick layer of lubricating grease is applied to a glass plate and is subjected to the effect of still water for 3 hours at a specified temperature. Afterwards, any changes will be evaluated.

DIN 51 807-2

Greases (pastes)

Testing of lubricating greases in the presence of water, dynamic test 

Water resistance/
Evaluation class of mass loss at stated test temperature

1 h, 40 °C or 80 °C water temperature, 600 rpm

Water is sprayed on a grooved ball bearing that is filled with lubricating grease. The change in the mass of the grease in the bearing is measured.

DIN 51 810-1

Rolling bearing greases

Determination of shear viscosity of lubricating greases using a rotation viscosimeter 
Part 1: Ball/plate mearurement system

Apparent dynamic viscosity/
Pa . s or in %

For lubricating greases in NLGI classes 000 to 2 at constant shear rate. Test run at stipulated speeds and times.

The shear viscosity of lubricating grease is determined by measuring the torque at a constant temperature and speed. The initial and final viscosity are measured. The shear viscosity indicates the stability of a grease.

DIN 51 818


Lubricants; consistency classification of lubricating greases; NLGI grades

NLGI grades/
NLGI grade

Measurement of the worked penetration after 60 double cycles at 25 °C as defined in DIN ISO 2137

Classification of lubricating greases by level of worked penetration for simple marking of products to indicate consistency.

DIN 51 821

Roller bearing greases

Testing of lubricants using the FAG FE9 rolling bearing test device
Part 1: General working principles
Part 2: A/1500/6000 test method

FE 9

Lubrication greases NLGI 1 to 4, between 120 °C an 200 °C

Mechanical dynamic testing of lubricants to determine the lifespan under realistic conditions. Several bearings are filled with grease and tested until they fail. The test method described in part 2 is used to determine the upper operating temperature for rolling bearing greases. Under these test conditions: installation type A, axial load 1500 N and speed 6000 rpm, the grease achieved 100 hours at the to-be-stated temperature. The probability of bearing failure is 50 % (F50).

DIN 51 834-2


Testing of lubricants; Tribological test in the translatory oscillation apparatus (SRV). Determination of measured quantities for friction and wear for lubricating oils

SRV test/

Cylinder/disc, 450 N, 1000 µm, 50 Hz, 2h (OKS standard)

The test establishes the friction coefficient between the specimens and the wear on the specimens after a specified test duration.

DIN EN ISO 16047

Screw pastes

Thread friction coefficient


Screws: ISO 4017 M10x55-8.8 vgs
nut: ISO 4032 M10-10 vgs.

Determination of friction coefficient by tightening of threaded fasteners.

DIN ISO 2137

Greases, pastes

- unworked penetration
- worked penetraton
- penetration loss

0,1 mm
0,1 mm
0,1 mm

- no shear stress
- with shear stress (60 double cycles)
- with shear stress

Determination of the consistency of a lubricant with and without application of shear stress.

E DIN 51 833

Assembly pastes


µ, N


Testing of the lubricating effect of pastes under very high pressures at low speeds.

SEB 181 302

Roller bearing greases



43 lbs

Determination of the wear protection properties of a rolling bearing grease for a defined load


Chemical Tests

applicable to


Meas. Unit



DIN 50 017

Condensation water test

Degree of corrosion

µm, h

Testing of corrosion protection properties in humid atmospheres for a defined coating thickness (µm) until the first traces of rust appear (h).

DIN 50 021

Spray tests with different sodium chloride solutions

Degree of corrosion h

DIN 53 210
for specified coating thickness until first rust appears

Testing of corrosion protection properties in a salty atmosphere

DIN 51 802

Roller bearing greases

Testing lubricating greases for their corrosion inhibiting properties

Corrosion grade

Three times 8 hours of operation each interrupted by 16 hour breaks at room temperature using distilled water.

Testing of corrosion protection of greases when used in rolling and friction bearings. The grease is tested by adding distilled water to ball joint bearings. Then the tracks of the outer rings are checked for corrosion.

DIN 51 808


Determination of oxidation stability of lubrication greases, oxygen method.

Oxidation stability/

100 h or 400 h, 99 °C, initial pressure 7.0 bar 

Oxidation stability provides information about the behaviour of thin layers of lubrication grease, such as in rolling bearings that are subjected to atmospheric effects under static conditions over a long period of time. The test is carried out at a specified pressure for 100 for 400 hours at 99 °C. Afterwards, the drop in pressure is measured. This doesn't say anything about the shelf life of packaged grease substances. 

DIN 51 811

Rolling bearing greases

Testing of the corrosive effect of lubrication greases on copper, copper strip test method

Copper corrosion/
Corrosion grade at stated test temperature

24 h/100 °C (OKS Standard)

This test is used to determine how corrosive lubricating grease is to copper. A smoothed copper strip is immersed in the lubricating grease for 24 h at a constant temperature, usually 50 °C or 100 °C. Afterwards, the corrosion grade is determined based on the discolouration. 

Aqueous substances

pH value



Physical Tests

applicable to


Meas. Unit



DIN 50 981
DIN 50 984

Layer thickness


DIN 50 982-2

Determination of layer thickness.

DIN 51 412-1
(DIN IEC 247)


Testing of petroleum products; Determination of the electrical conductivity
Part 1: Laboratory method
Part 2: Field method

Electrical conductivity/
pS/m (Ohm x cm)

at 23 °C

Procedure for measurement of the electrical conductivity of liquids. Cannot be used with insulating oils. The test makes use of a conductive receptacle containing approx. 100 ml of the liquid under test, to which a direct current voltage of 100 V is applied. The electrical conductivity can be calculated from the measured voltage drop.

DIN 51 562-1


Viscosimetry; Measurement of kinematic viscosity using the Ubbelohde viscometer; Part 1: Geometrical design and performance of measurements


at 40 °C, at 100 °C
Silicone oil
at 25 °C

Method for the determination of the kinematic viscosity of transparent, Newtonian liquids in the range 0.35 mm²/s to 100,000 mm²/s at temperatures between 10 °C and 100 °C. The test measures the time taken for a certain volume (measured by two ring marks) of the liquid under test to flow through a capillary tube under the influence of gravity.

DIN 51 581


Determination of evaporation loss

Evaporation loss/
% in mass

T = 250 °C, 60 min

Determination of evaporation loss of an oil over a specified time period t at a specific temperature T.

DIN 51 755

Oils, solvents

Determination of flash point using the Abel-Pensky closed cup method

Flash point/

Temperature range from 5 °C to 65 °C

Determination of flash point of mineral oils and other combustible liquids. Other tests are used for higher flash points.

DIN 51 757


Determination of density of mineral oils and related substances

kg/l of g/ml

at 15 °C

To convert mass to and from volume. 

DIN 51 805
Oils, Greases

Determination of flow pressure of lubricating greases, Kesternich method

Flow pressure/
mbar, °C

Lower operating temperature for lubricating greases according to DIN: flow pressure < 1.400 mbar

A test nozzle filled with lubricating grease is connected to a pressurized gas source and a pressure gauge. At a specific, constant temperature, the pressure is continually increased until the lubricating grease rope snaps and the pressurized gas escapes through the nozzle. The lower operating temperature for lubricating greases according to DIN 51 825 is defined by the flow pressure as maximally 1400 mbar.

DIN 51 813


Determination of the amount of solid substances in lubrication greases, particle sizes > 25 µm

Solids content/
mg/kg or ppm

Only for soap-based lubrication greases without added solid lubricants 

Determination of the amount of solids, impurities in lubricant greases that can cause lubrication problems, noise and wear. 500 g of the grease is pressed through a sieve. Then, the residue in the sieve is mixed with a solvent and impurities are washed out.

DIN 51 817

Greases (Pastes)

Determination of oil separation from lubricating grease under static conditions

Oil separation/
% in mass


Determination of the bleed properties over a specified time period t and temperature T

DIN 51 832


Particle size


d 50, d 99, max.

Determination of average (d50) and maximum (d99) particle size.

DIN 52 612

Thermally conductive pastes

Thermal conductivity



Testing of thermal conductivity of a substance.

DIN 53 481
DIN IEC 234-2

Insulating pastes,

Thermally conductive pastes

Dielectric strength


at 20 °C,  0,05 inch separation

Electrical testing.

DIN 53 482

Insulating pastes,

Thermally conductive pastes

Electrical greases

Specific resistance

Ohm x cm

at 25 °C,
Electrode separation 1 cm,
Electrode area 1 cm²

Testing of electrical resistance of a substance.

DIN 58 397-1


Evaporation loss

Weight percent


Determination of the evaporation loss of a lubricant over a defined period of time, t, at a defined temperature, T.

DIN EN 22719
DIN ISO 2592




> 79 °C
< 65 °C
< 5 °C

Lowest temperature at which the evaporating oil can be ignited by an external ignition source.


All substances



at 20 °C


DIN ISO 2176

Greases, pastes

Drop point



Temperature at which the structure of the grease breaks down.

DIN ISO 3016




3 °C steps

Temperature at which the oil first becomes capable of flow.

Insulating pastes

Dielectric constants


1 kHz - 10 MHz

Electrical testing.

Insulating pastes

Arc stability



Electrical testing.

Insulating pastes

Dielectric loss factor


1 kHz - 10 MHz

Measurement of dielectric loss factor.

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  • Tribology Basic Knowledge

    Tribology Basic Knowledge

    Fundamentals about lubricants and tribology