Group F (spindle, bearings and clutch) detailed breakdown is specified by the GB 7631.4-89, divided into 2 categories.
     FC is refined mineral oils and additives to improve their resistance to corrosion and oxidation resistance. Suitable for sliding or rolling bearings and related clutch pressure, oil bath and oil mist (aerosols) lubrication.

FD is to improve the abrasion resistance on the basis of the FC. Suitable for sliding or rolling bearing pressure, oil bath and oil mist (aerosols) lubrication.

In order to prevent corrosion or slipping clutch, FC oil should be free anti-wear or extreme pressure additives.

Classification according to GB 7631.4-89 standard-setting product standards SH 0017-90 "oil bearing" was implemented on April 1, 1992, instead of SYl229--82 (88) "spindle oil." The new standard l-FC 2-100 points, etc. 11 viscosity number, L-FD 2-22 points etc. 7 viscosity number.