The FZG Test evaluates fluid lubricating and wear protection properties at the interface of a loaded set of gears.

During the FZG* Test, the gears are loaded through a torsional coupling that is set to known load conditions or stages. The gears are rotated by a variable speed electric motor. Fluid temperature is controlled by heating and/or cooling elements.

FZG Gear Wear (ASTM D5182)
Evaluates gear tooth face scuffing resistance of fluids using A profile gears. The rig is operated at 1450 rpm through up to 12 progressive load stages at 15 minute intervals. Standard tests are run at a fluid temperature of 90oC, though the MERCON®-V/SP test is run at 150oC. Gear teeth are inspected after each load stage for scuffing. In addition to a visual evaluation of gear tooth condition, gear weight loss is measured.

FZG Gear Wear (ASTM D4998)
Evaluates gear tooth face wear resistance of fluids using A profile gears. The rig is operated at 100 rpm under constant load for 20 hours. A visual tooth surface rating and gear weight loss are measured.

FZG Pitting - Type C Gears
Evaluates gear pitting resistance of fluids using C profile gears. Tests are run up to 300 hours under constant load, temperature, and speed. Inspections are conducted at predetermined intervals for pitting damage on the gear tooth faces.

FZG A10/16.6R/120
A more severe version of the ASTM D5182 Load Stage Wear test. This test requires A10 gears (half the tooth width of the A gears), and is run at 2880 rpm in reverse mode.

In addition to standardized FZG tests, Intertek Automotive Research has extensive experience with customized FZG tests. Gear type, fluid temperature, gear load, and rotation speed can all be controlled to customer defined settings.


*FZG stands for "Forschungsstelle fur Zahnrader und Getriebebau", the Technical Institute for the Study of Gears and Drive Mechanisms.

Related Links

Contact Intertek