What is a 4-Ball wear Test?

In the 4-Ball Wear test, a steel ball is rotated against three lubricated stationary steel balls under a specified load, speed, temperature and time, per ASTM D-2266 (grease) or ASTM D-4172 (oils). The better the lubricant is at preventing wear, the smaller the wear scar will be on the three stationary balls.

What is 4-Ball Weld load?

The weld load is the load step at which the test balls local temperature reached the melting point of steel, that fused the four balls. At this point the friction torque sensor in the four-ball tester exceeds the safety value and shuts down the motor. This represents the failure by grease lubricants to prevent seizure.

Which material is used for ball in 4-ball tester?

A rotating steel ball is pressed against three steel balls firmly held together and immersed in lubricant under test. The test load, duration, temperature and rotational speed are set in accordance with standard test schedule.

What is the diameter of ball used in four-ball tester?

1/2 inch diameter
Four-Ball Wear Tester The machine compares lubricants using the average size of the scar diameters worn on three, lubricant-covered, 1/2 inch diameter steel balls that are clamped together, with a fourth ball seated within the cavity.

What does EP load represent?

January 26, 2017 – What does EP mean in the name of a lubricating grease? The term EP refers to extreme pressure, which means the grease is formulated with additives that increase its load carrying capacity.

What is SRV test?

Tribological Testing by SRV® SRV stands for Schwingung (Oscillating), Reibung (Friction), Verschleiß (Wear). The SRV measures the physical interactions between a lubricant and two specimens in a loaded contact in either rotational or linear oscillatory motion.

What is fzg test?

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.

What are tribological properties?

Tribological Properties of Interfacial Molecular Films Tribology deals with friction, wear, and lubrication of interacting surfaces. Interfacial molecular films refer to adsorbed, self-assembled, or functionally grafted molecular systems that form, through physical and chemical processes, near or on a surface.

What does WP mean in electrical?

The watt-peak (Wp) is therefore an indication based on a standard. It corresponds to the maximum electrical power that can be supplied by a photovoltaic panel under standard temperature and sunlight conditions. 1 kWp = 1,000 Wp.

How can wear scar properties and coefficient of friction of a lubricating grease can be determined?

Wear scar properties and coefficient of friction of a lubricating grease can also be determined using the 4 Ball Wear configuration. The purpose of this test is to determine the wear preventive characteristics of a lubricant.