DUCOM Four Ball Tester

Ducom four-ball tester will allow you to characterize lubricants by their wear preventive (WP), extreme pressure (EP), frictional and fatigue properties.

The four-ball tester uses a configuration where three balls are at the bottom and one is on top. Lubricant properties are tested by containing the bottom three balls in a pot and pressing them firmly against the top ball, which can be made to rotate at a range of different speeds. After this rotational friction analysis, the lubricant under test can be characterized by measuring the wear scar diameter on the balls. Characterisation of the fatigue and extreme pressure properties of the lubricant occurs by evaluating the force load at which lubricant fails – at this load, the balls will weld together.

Ducom Four ball tester- Manual

Figure 1. Ducom Four ball tester- Manual

Test area schematic

Test area schematic

Four ball arrangement

Four ball arrangement

Welded balls

Welded balls

Wear scar on steel ball

Wear scar on steel ball

Applications of the Four-Ball Tester

  • Determine extreme pressure (EP), wear preventive (WP), frictional and fatigue properties of lubricants.
  • Testing and verifying the quality of oil that you’ve either produced yourself or purchased from wholesalers.
  • Test whether nanoparticle coatings have useful wear-preventive properties.
  • Compare lubricant performance at a range of different loads and temperatures, across a variety of different compositions and manufacturers. By comparing new and used oils, you can see how lubrication properties deteriorate over time – or you might want to compare the lubrication properties of bio-degradable or vegetable oils compared to synthetic oils, or those derived from hydrocarbonate cracking.
  • Test polymeric viscosity modifier to achieve better shear stability and minimize the viscosity loss.

Grease Sample

Grease Sample

Oil Sample

Oil Sample

Please click here if you would like more information on the product in this article or a quote

Functional Features

  • EP and WP test combined in single instrument
  • Easy mounting/disassembling the of sample, faster test preparation
  • Computer/manual controlled operation
  • Real time acquisition of frictional force
  • Display of average COF after completion of test
  • Facility to store multiple test data results
  • Compare four test results in one screen
  • Quick online calibration facility
  • Image acquisition system (optional add-on)
  • Automatic loading (optional add-on)
  • Modular electronics for ease in servicing
  • Inbuilt storage for accessories, tools and samples (dead weight loading option only).
  • Safety interlocks for the safety of the user

Collet master

Collet master


Technical Specifications

Test variables Units TR30L Remarks
Test speed RPM 300-3000 Variable, high speed provision on request
Test loads N 100-10000 Variable, manual loading or software controlled
Frictional torque Nm 0-16
Temperatures °C Ambient to 120 Variable, higher temperatures up to 200 °C on request
Power V/Hz/Ø 415/50/3

Optional Add-ons

  • Pneumatic loading option: the load is applied and controlled by software with a variety of different profiles available.
  • KRL shear stability add-on, which allows testing to determine the viscosity loss of lubricants.
  • Rolling fatigue attachment. Lubricants can sometimes produce fatigue failures in rolling contacts; this rolling fatigue attachment uses a fast-rotation attachment which allows up to 10000 RPM; this allows the test to be completed very quickly.
  • Thrust washer attachment: rubbing contact between materials incurs its own wear rate, which can be measured with this attachment.
  • High temperature ball pot – this attachment can heat the lubricant pot to a range of different temperatures, from room temperature to 200 °C.
  • Image acquisition system: this allows you to measure the wear scars on the balls quickly and accurately without having to take them out of the tester.

Optical microscope

Optical microscope

Instrument control and Data acquisition

The four-ball tester (TR-30) comes fully integrated with measurement instrumentation and software controller. This allows you to measure variables such as the normal load, speed, lubricant temperature and the frictional torque developed at the contact between the balls. This data can then be acquired in real-time and graphed online. You can measure the scar diameter on the balls – and hence the lubrication properties of the lubricant – either by detaching them and examining them with a measuring microscope, or using the add-on image acquisition system which will do this automatically.

The optional software controlled instrument allows you to set all of these parameters in a user-friendly interface; the PC for the software controlled option will acquire and display values for the normal load, frictional force temperature and coefficient of friction. Data can be graphed in real-time, exported to Excel spreadsheets, and data from different runs can be compared by superimposing the graphs. As well as this, the image acquisition system will take photographs of the scar tracks on the measuring balls and upload them to the PC.

Standard scope of supply

S. No Included Accessories and Consumables Number
1. Four ball tester basic instrument 1
2. Electronic controller 1
3. Dead weights (for manual loading) 1 set
4. Software (Data acquisition system) 1
4. Measuring microscope 1
5. Ball pot assembly 2 sets#
6. Steel/test balls (12.7 mm Diameter), AISI E52100 steel balls, hardened to 64-66 HRC 50#
7. Collets 2#
8. Collet master 1
9. Torque wrench 1
10. Calibration kit 1
11. Operating manual 2
12. Tool kit 1
13. Dust cover for machine and controller 1 set
14. Data acquisition cable, power cable 1 set
15. Warranty 1 Year

# denotes consumables, has to be ordered separately if more numbers are required

. .
KRL Ball pot assembly 1
KRL Collet 2
Water re-circulation unit 1 set
Taper roller bearing 1
Hook Spanner 1
Cooling Adaptor 1
Image Acquisition System*
Mechanical System 1
Software: Scarview 1
Automated Loading Arrangement*
Pneumatic Loading*
RFA Ball pot assembly 1
Oil Tank 1
Peristaltic pump 1
Special ball race to match ball profile 1
Thrust Washer Attachment*
Low speed pulley 1
Ball pot assembly for thrust washer attachment 1
Collet for thrust washer attachment 1

Utilities required (please note following items will be under user scope)

. .
Computer*: Minimum configuration for software operation is mentioned, customer can use any higher end. INTEL i3 CORE, 2 GB RAM, 500 GB HDD, DVDR, 1.7 GHz Clock speed, WINDOWS 7 operating system, PCI & PCI- Xpress SLOT -1 No. each, USB PORT: 2 No., COMPORT: 1 No., Color Monitor, Mouse, Keyboard.
Power required 415 V/3 Phase/50 Hz, cooling water, UPS*, computer table and chair* and facility for disposing the tested balls, tested lubricant has to be arranged by the user for proper installation and commissioning of the instrument.

Please Note: Air compressor for automatic loading, computer, UPS, weighing balance or any optional attachments, consumables, devices or accessories other than mentioned is not included in standard scope of supply, has to be ordered separately. Please contacts Ducom sales professional for any further clarifications.

*Denotes optional modules and attachments

About Ducom’s Testing Facilities

Fortune 500 companies, from small research laboratories to major R+D departments in large companies, use Ducom for tribological tests. There are a number of different tribometers, mechanical testers and lubricant testers at three locations: including in India, the Netherlands, and the USA. Ducom will allow you to remotely witness tests by video, saving on the costs of having to travel to these facilities in person.

These test facilities have been in service since 1999, providing tribological testing facilities to academia and industry alike. The testers used by Ducom are state-of-the-art and regularly calibrated to ensure that their results are accurate and reproducible. Even in the field of tribological testing alone, the staff at the Ducom Testing Facility have over fifty years of combined experience with this state-of the art equipment. With Ducom, you can get your testing done without capital investment or additional manpower requirement. Using their centralized facilities, you avoid the need to train testers, and avoid maintenance and AMC costs for the equipment. In addition, they provide excellent security; the facility has limited access and non-disclosure agreements are available. All tests will be reported in accordance with existing standards.

This information has been sourced, reviewed and adapted from materials provided by Ducom.

For more information on this source, please visit Ducom.


Ducom Four Ball Tester-Pneumatic Loading
Rolling Fatigue Test attachment IP300
KRL attachment CEC-L-45-T-99
Ducom Four Ball Tester (table top tribometer)
Seal testing


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Ducom. (2019, July 18). DUCOM Four Ball Tester. AZoM. Retrieved on November 15, 2019 from https://www.azom.com/article.aspx?ArticleID=15391.

  • MLA

    Ducom. "DUCOM Four Ball Tester". AZoM. 15 November 2019. <https://www.azom.com/article.aspx?ArticleID=15391>.

  • Chicago

    Ducom. "DUCOM Four Ball Tester". AZoM. https://www.azom.com/article.aspx?ArticleID=15391. (accessed November 15, 2019).

  • Harvard

    Ducom. 2019. DUCOM Four Ball Tester. AZoM, viewed 15 November 2019, https://www.azom.com/article.aspx?ArticleID=15391.

Ask A Question

Do you have a question you'd like to ask regarding this article?

Leave your feedback