 |
|
|
 |
|
|
Saponification Number
Table of Contents
Physical & Chemical Properties
Saponification is a chemical test indicating the amount of fatty material in the oil and, therefore, one index of anti-friction. Saponification is a chemical process of converting fats to soap. Certain lubricants such as worm gear oils, steam cylinder oils, machine tool way lubricants, and pneumatic tool oils, contain fatty type additives to improve anti-friction properties. Saponification number is performed according to ASTM D 94. The Saponification number indicates the amount of fatty substances in the oil. Saponification number is the number of milligrams of KOH that combines with the fat in 1 gram of oil to form the soap. Therefore, the higher the number, the greater the amount of fatty material.
Anti-friction is measured directly by laboratory bench tests, where a low coefficient of friction ("f"), measured under conditions of boundary lubrication indicates good anti-friction performance. Examples of bench tests are the four ball test machine and the pin-on-disk apparatus. A pin-on-disk apparatus with steel sliding on steel, with a base oil would give an f of 0.10 to 0.15, whereas the addition of 2% oleic acid to the oil, f would be reduced to 0.05 to 0.08. In an industrial machine, anti-friction reduces power requirements. No bench machine has been found to correlate satisfactorily with an industrial machine.
However, if materials and operating conditions in the bench machine simulates the industrial machine as closely as possible, the results are useful for screening lubricants, revealing wear mechanism, and warning of problems. The final lubricant test is in the industrial machine itself.
For more information call 1-888-HERGUTH (437-4884) | |
|