1) Reduce friction - Decreasing friction decreases energy requirement and heat buildup.
2) Reduce wear - Decreasing wears increases equipment life and decreases mainte-nance costs.
3) Cool rubbing surfaces - Cooling of rubbing parts maintains working tolerances, extends oil life, and removes heat from the system.
4) Prevent corrosion - Minimizing surface corrosion decreases friction, heat, and component wear. Generally provided by additives rather than the base lubricant.
5) Seal and reduce contaminant buildup - Improves gas seal on piston rings and packing rings, and flushes away contaminants from moving parts.
6) Dampen shock - Shock loads are cushioned, thereby reducing vibration and noise, and increasing component life.