Classification of industrial oils based on viscosity
This classification is mainly based on ISO viscosity grades, which define the oil’s kinematic viscosity at 40 °C with a permissible variation of ±10%. The ISO viscosity grade of industrial oils (explained in detail and compared with other viscosity grading systems on the next page) approximately represents the mid‑point of the allowable viscosity range in centistokes (cSt) at 40 °C.
Classification of industrial oil quality levels
Due to the very wide variety of applications and quality levels of industrial oils, it is not possible to list all relevant standards here, and the specifications for each specific oil are described separately. Many industrial oil standards have been developed by reputable equipment manufacturers and are widely accepted as industry references.
