Summary of the ASTM D2783-19 Standard
This test method is used to assess the load carrying properties of lubricating fluids under extreme pressure conditions. The test is performed by rotating a ball against three balls in a container submerged under the test lubricant at various contact pressures, till failure is observed. Three determinations are made:
- Load-Wear Index
- Last non-seizure load
- Weld Point, by means of the Four-Ball Extreme Pressure (EP)
These tests are done using Multi-functional tribometer MFT-5000. During the test inline torque, down force, acoustic emission, electrical contact resistance and temperature values are recorded and reported. The test involves increasing load in steps of 10 seconds each till the balls are welded. The fully automated linear loading mode of MFT-5000 tester also allows to run the same test in one step by applying a linearly increasing force at a controlled rate vs. multiple steps each at constant load.
Four-ball Method Parameters
| Balls: | AISI standard steel No. E-52100 Grade 25 EP (100Cr6) |
| Ball diameter: | 12.7 mm |
| Normal Force: | Step increasing load (6, 8,10,13,16, 20, 24, 32, 40, 50, 63, 80, 100, 126, 160, 200, 250, 315, 400, 500, 620, 800) Kgf |
| Test Duration: | 10 seconds for each step |
| Speed: | 1760 rpm |
| Temperature: | Ambient (27 °C) |
| Lubrication: | Lubricating Liquid |
| Data: | Torque (Tx) Normal Force (Fz) Frequency (Hz) Temperature (°C) |
Data Summary
