Falex 4-Ball EP Tester

Falex 4-Ball EP Tester

  • Historically very popular test instrument for the evaluation of Extreme Pressure properties of lubricating oils and greases
  • Used extensively to evaluate extreme pressure additives and properties, that means the property of a lubricant to separate two moving parts under very high pressures
  • Relatively simple setup, low cost of test specimens (4 high polish, high roundness bearing balls)
    • Three ½ inch diameter steel balls are clamped together and covered with the test lubricant. A fourth ball is pressed into the cavity formed by the three clamped balls for three-point contact, and rotated for a set duration.
  • Various modifications of test methods are possible
    • Weld Point  = finding the lowest load at which the lubricant can no longer separate the moving ball from the fixed balls
    • Last Non-Seizure Load = finding the load where no significant wear occurs
    • Load Wear Index = a combined factor, based on the measured wear scars after individual tests at different loads.  Gives an idea about combined anti-wear and extreme pressure property



24 February 2017


Lubricants and Material Tribometers
© 2017 Falex Application Center for industrial Tribology