This Defense Standard specifies the requirements for two grades of petroleum base hydraulic fluid.

Hydraulic fluid, petroleum, super clean, is for use in aircraft and other critical system where a high degree of fluid cleanliness is required. It is suitable for use in unpressurized hydraulic systems operating between minus 54° C and plus 90° C and between minus 54 and plus 135° C in pressurized system.

Hydraulic fluid, petroleum, normal, is for use in non-critical systems and other applications not requiring the high degree of cleanliness of the super clean grade. It is suitable for use in unpressurized hydraulic system operating between minus 54° C and plus 90° C and between minus 54° C and plus 135° C in pressurized systems.