Bearing Testing
Bearing testing of rolling and plain bearings, bearing materials and lubricants under the conditions of your application, from material screening to full-bearing tests and analysis of the tested parts.
Why bearings fail
- Wear. Insufficient or degraded lubricant and mixed friction remove material from raceways, rolling elements and cages.
- Rolling contact fatigue. Repeated stress cycles cause pitting and spalling of the raceways and rolling elements.
- Fretting. Small oscillating movements, for example from vibration while the bearing is at standstill, damage the contact even though the bearing hardly rotates.
- End of grease life. At high temperature and speed the grease ages and can no longer lubricate the bearing.
- Seizure in plain bearings. When the lubricating film breaks down, for example at start-up or under high load, the sliding surfaces come into contact.
Bearing tests in our network
We choose the setup that matches your question: a fast screening on a tribometer, a standardised full-bearing test, or a test on a component rig.
| Test setup | What it shows | Standard |
|---|---|---|
| FE8 rolling bearing test rig | Wear of rolling elements and cage, friction torque and temperature with your oil or grease | DIN 51819 |
| FE9 rolling bearing test rig | Service life of a grease in angular contact ball bearings at a chosen temperature | DIN 51821 |
| Rolling bearing friction rig | Friction of complete ball bearings with your lubricant | – |
| Rolling bearing test rig | Rolling contact fatigue and wear tests of rolling bearings | – |
| Journal bearing test rig | Friction, bearing temperature, speed and acoustic emission | – |
| Tribometer tests of plain bearing materials | Friction and wear of metallic and polymer bearing materials, bushings and thrust washers | ISO 7148, ASTM D3702 |
| Oscillating (SRV) tribometer | Fretting wear protection of greases at high contact pressure | ASTM D7594 |
| Refrigerant bearing tribometer | Lubrication of rolling bearings in refrigerants | – |
What we measure
- Friction torque and temperature, recorded during the test
- Wear of rolling elements and cages (mass loss) and of sliding surfaces
- Running time until failure
- Surfaces after the test, with 3D surface topography and SEM/EDX
Key bearing test standards
These are the methods most often used for bearings, bearing materials and bearing lubricants. Where no standard fits your application, we propose a test closer to your operating conditions. Search all standards in our test standards finder.
Rolling bearing tests
| Standard | Test | What it measures |
|---|---|---|
| DIN 51819 | FE8 rolling bearing test (Part 2: greases, Part 3: oils) | Wear of rolling elements and cage, and friction |
| DIN 51821 | FE9 rolling bearing grease test | Grease service life (F50) at a chosen temperature |
| ASTM D3336 | Life of greases in ball bearings at elevated temperatures | Grease life at light load, high speed and high temperature |
| IP 168 | Rolling bearing performance of lubricating grease | Lubricating ability, physical changes, oil separation and leakage |
| ASTM D3527 | Life performance of automotive wheel bearing grease | High-temperature life of wheel bearing greases |
| EN 12082-1 | Railway axleboxes, test procedures | Rig test of the axlebox: bearings, housing, seals and grease |
Fretting and false brinelling
| Standard | Test | What it measures |
|---|---|---|
| ASTM D7594 | Fretting wear of greases, SRV test machine | Fretting wear resistance of greases at high Hertzian pressure |
| ASTM D4170 | Fafnir fretting wear test | Fretting wear protection of greases in oscillating thrust ball bearings |
Lubricant tests carried out in bearings
| Standard | Test | What it measures |
|---|---|---|
| ASTM D6138 | Emcor test | Corrosion protection of greases in ball bearings under wet, dynamic conditions |
| ASTM D1743 | Corrosion-preventive properties of greases | Corrosion protection in tapered roller bearings |
| ASTM D1264 | Water washout of greases | Grease washed out of a ball bearing by a water jet |
| ASTM D1478 | Low-temperature torque of ball bearing grease | Starting and running torque at low temperature |
| ASTM D4693 | Low-temperature torque of grease-lubricated wheel bearings | Torque at low temperature |
| ASTM D4290 | Leakage of wheel bearing grease, accelerated | Grease and oil leakage at high temperature |
| DIN 51350-6 / ISO 26422 | Shear stability in a tapered roller bearing (KRL) | Permanent viscosity loss of polymer-containing oils |
Plain bearing materials
| Standard | Test | What it measures |
|---|---|---|
| ISO 7148-1 | Testing of bearing metals | Friction and wear of metallic bearing materials under boundary lubrication |
| ISO 7148-2 | Testing of polymer-based bearing materials | Friction and wear of polymer bearing materials, dry and lubricated |
| ASTM D3702 | Thrust washer test | Wear rate and friction of self-lubricating materials |
From test to design: analysis and simulation
A test result becomes useful when you know why the bearing behaved as it did. After the test, the surfaces can be examined with 3D topography and SEM/EDX, and the used lubricant analysed (see Advanced Analytics). For plain bearings, simulation helps to explore operating conditions beyond the test: see Modelling & Simulation, or try the free journal bearing, tilting pad thrust bearing and spiral groove bearing apps on Tribology Universe.
Industries
- Wind energy: rolling bearing lubricants and greases
- Automotive: bearing lubricants, including fluids for electric drives
- Hydrogen: bearing materials in hydrogen
One contact, the whole European network
i-TRIBOMAT is the single entry point to more than 130 tribometers and more than 250 experts across Europe. You do not need to find, compare and coordinate several laboratories: we do it for you.
- One contact and one offer for the whole programme
- Independent choice of setup: we match your application to the right test, not to the equipment we happen to own
- One consistent report and, on request, your results in your own online database (see Data-Driven Services)
- Confidentiality covered by a single agreement
Frequently asked questions
Can you test my own bearings?
It depends on the bearing type and size, because each rig takes a defined range of bearings. Send us the bearing designation and your operating conditions and we will tell you which test is possible. Bearing materials can also be screened on tribometers with test specimens.
What is the difference between FE8 and FE9 tests?
The FE8 test (DIN 51819) measures the wear of rolling elements and cage, and the friction, of rolling bearings lubricated with a given oil or grease. The FE9 test (DIN 51821) measures how long a grease lasts in angular contact ball bearings at a chosen temperature. FE9 results are used to define the upper operating temperature of greases in the DIN 51825 classification.
How do you test fretting protection of greases?
With ASTM D7594 on an oscillating (SRV) tribometer, which ranks greases by their fretting wear resistance at high contact pressure. If your application needs other conditions, we propose a dedicated test.
How do I start?
Send us a short description of the bearing, the lubricant, the load, speed and temperature, and the question you want answered. We reply with a test proposal and an offer.
Or write to office@i-tribomat.eu. See also all tribological characterisation services.