• Four Ball Tester

Four Ball Tester



Determines the Wear Preventative (WP) and Extreme Pressure (EP) characteristics of lubricating oils and greases in sliding steel-on-steel applications. The test consists of rotating a steel ball under load against three stationary steel balls coated with lubricant. Measurements are taken at the rotating speeds, temperatures, and duration as specified by published standards. The load-wear index can be calculated from the weld point in EP tests, and lubricant comparisons can be made based upon scar diameters incurred from wear tests.

  • Conforms to ASTM D2266, D2596, IP 239, and related specifications
  • Performs Wear Preventative (WP) and Extreme Pressure (EP) tests
  • Displays and records normal load, frictional torque, time, and temperature
  • Test speeds and temperatures are electronically controlled
  • Data Acquisition Software and Card are included
  • Custom configurations are available
  • Precise variable loading capability

Four Ball Tester performs both Wear Preventative (WP) and Extreme Pressure (EP) analyses for measuring the wear and frictional properties of lubricants under sliding steel-on-steel test conditions. Tests are performed in accordance to the latest ASTM and IP published methods. Normal load on the ball assembly and frictional torque are measured through load cells. Data is processed and stored using an advanced data acquisition and processing software package. Test results can be plotted and compared, as well as exported to other programs. Wear scars on the steel balls are measured and recorded with a High Resolution Digital Microscope available as a recommended accessory for the Four Ball Tester. 


High Resolution Digital Microscope - Koehler's Four Ball Microscope is a versatile device for measuring the wear scar diameter on a steel test ball. This apparatus consists of the “Dinolite” Microscope with “DinoCapture” Software mounted at an angle on an aluminum base. The device is designed to measure the wear scar without removing the test balls from the ball pot allowing for a safer measurement procedure. The wear scar can be viewed through an external PC. The software measures the wear scar using a diameter and line tool. The images can be saved at varied resolutions on a PC.

  • Set of Weights
  • Ball Chucks
  • Ball Pot
  • Ball Chuck Remover
  • Ball Rack
  • Ball Clamp Ring
  • Ball Holder Base Disc
  • Set of Hand Tools
  • Torque Wrench
  • Electrical Controller
  • Connecting Cables
  • Data Acquisition Software
  • Calibration and Test Reports
  • Ordering
Conforms to the specifications of: ASTM D2266, D2596, D2783, D4172, D5183*, IP 239
Drive Motor: 1.5 kW
Test Speeds: 1200, 1440, 1760 rpm
Optional Test Speeds (min/max): 1000/3000, 300/3000 rpm
Maximum Axial Load: 10000 N at 3000 rpm or 12000 N at 1800 rpm
Test Duration (min/max): 1/9999 min
Test Ball diameter: 12.7 mm

220V, 60Hz, 3 phase
440V, 50Hz, 3 phase

Net Weight: 927 lbs (420.5 kg)

Shipping Weight: 1200 lbs (544.3 kg)

Dimensions: 38x48x52 in. (96.5x121.9x132.1 cm)

  • K93105 Test Balls (Pack of 100)
  • K93111 High Resolution Digital Microscope