4 Ball Lubricant Tester for Lubricant Extreme Pressure (EP) Test

 

A Four Ball Lubricant Tester is a type of instrument used to determine the load-carrying lubricating properties of different oils, greases, and other lubricating fluids.

The 4-ball tester is used to evaluate extreme pressure (EP), friction, load-wear index, ball weld point, and wear preventive additives for lubricant fluid, lube grease, oil, and lubricant additives.

 

Test Method Description of 4 Ball Test

Place 3 steel balls in a fixed position and rotate a 4th ball against them under a load and speed. The four balls are in point contact, and the contact points are immersed in the lubricant being tested. The extreme pressure (EP), friction, and load-wear are been tested.

The 4 Ball Wear Tester is commonly used in the lubricants industry, the test results can compare the performance of different lubricants and it helps to optimize the lubricant for a particular application.

 

What properties can the four-ball testing machine measure?

 

• Weld Point Load -PD
  The minimum load for sintering of steel balls under test conditions. It represents the ultimate working capacity of the lubricant.

Increase the load step by step at a certain temperature and speed. When the upper steel ball and the lower steel ball are welded at high temperature due to overload, the load value that the equipment has to stop running is the Weld Point PD. The higher the sintering load, the better the extreme pressure performance of the lubricant. The Weld Point Load is to examine the anti-wear, extreme pressure performance of lubricants under harsh conditions.

 

• Last Nonseizure Load - PB

The maximum load of seizure does not occur under test conditions. It represents the lubricant's oil film strength.

The higher the measured value of this index, the better the lubricant performance. The base oil has a great influence on the PB value, and the PB value of naphthenic oil or Recycled oil from waste oil is small.

 

• Scar diameter D

The wear scar diameter is one of the main test items of the four-ball testing. We often use this indicator to examine gear oil, hydraulic oil, metal processing oil, etc.

The smaller the scar and friction coefficient, the better the lubricity and the more energy-saving performance. The rounder the diameter of the wear scar, the more uniform the force, and the better the wear resistance and continuity of the lubricating oil.

 

                    Load-Wear Line - 4 ball testing

 

ABE - Compesnsation line
AB- Nonseizure range
B- Maximum nonseizure load point
BC-Delay seizure range
CD - Approaching seizure range
D - Weld load point
 

Testing Standards

 

Chinese Standards:

GB/T 3142-2019: Determination of bearing capacity of lubricants - (Four-Ball Method)
GB/T 12583-1998: Determination of extreme pressure properties of lubricants - (Four-Ball Method)
NB/SH/T 0189-2017: Determination of wear resistance of lubricating oil - (Four-Ball Method)
SH/T 0202-1992: Determination of extreme pressure properties of greases -(Four-Ball Method)
SH/T 0204-1992(2004): Determination of wear resistance of greases - (Four-Ball Method)
SH/T 0762-2005 Lubricating oil -- Determination of friction coefficient - (Four-Ball Method)

ASTM Standard:

ASTM D2266-01 (2015): Standard Test Method for Wear Preventive Characteristics of Lubricating Grease (Four-Ball Method)
ASTM D2783-03 (2014): Standard Test Method for Measurement of Extreme-Pressure Properties of Lubricating Fluids (Four-Ball Method)
ASTM D4172-18: Standard Test Method for Wear Preventive Characteristics of Lubricating Fluid (Four-Ball Method)
ASTM D5183-05 (2016): Standard Test Method for Determination of the Coefficient of Friction of Lubricants Using the Four-Ball Wear Test Machine

 

A 4-ball machine is mainly used to evaluate the extreme pressure and anti-wear performance of lubricating oils. It is a key device for quickly screening and developing additives and testing the performance of lubricating oil formulations. Generally speaking, the requirements for extreme pressure and anti-wear performance of lubricating oils for different uses vary greatly. For example:

 

• Industrial gear oil: requires extremely high welding load and good anti-wear property.
• Engine oil: More focus on anti-wear performance under medium and low loads (minimum wear scar diameter).
• Metalworking fluids: Require excellent extreme pressure performance in the cutting or forming processes.

 

For the R&D personnel of lubricating oil additives (especially anti-wear agents and extreme pressure agents), the 4-ball machine is a fast, economical, and effective tool to screen the additives. It can quickly evaluate the performance of new additives or formulations in anti-wear and extreme pressure aspects.

 

Chorus^® offers a wide range of EP/AW Additives for engine oils, gear oils, hydraulic oils, compressor oils, metalworking fluids, greases, and other lubricants at competitive prices. Get in touch.