Description
Castrol Alphasyn GS 320 is a premium synthetic gear lubricant engineered for demanding industrial applications where high temperatures, heavy loads, and continuous operation place significant stress on gear systems. It is based on carefully selected PAG fluids with antioxidant, rust-inhibiting, and Extreme Pressure (EP) additives that deliver superior performance compared with conventional mineral oils.
This advanced formulation helps minimise sludge and deposit formation, supports extended drain intervals, and reduces frictional energy losses for improved gearbox efficiency.
The Alphasyn GS range is particularly well-suited for high-temperature lubrication of gears and bearings, such as those in large-scale mills, calenders, and other industrial drives. These oils can operate continuously at elevated temperatures and handle intermittent peaks at even higher levels, offering protection in conditions where ordinary oils may fail.
Key Features
-
Synthetic PAG base with high-stability additives for excellent thermal and oxidative resistance.
-
ISO VG 320 viscosity — balanced film strength and load-carrying capability for heavy industrial gearboxes.
-
High thermal stability: Minimises sludge deposits and extends service life.
-
Reduced friction: Improves energy efficiency and lowers gear sump temperatures.
-
Enhanced wear protection: Helps protect gears and bearings under severe loads.
-
Wide service temperature range: Reliable performance from low to high thermal conditions.
Applications
Ideal for industrial enclosed gearboxes, especially in high-temperature and high-load environments such as mills, calenders, and heavy machinery gear drives. The 20 L canister format is convenient for refilling gear oil reservoirs or for use in maintenance servicing of industrial equipment




