In boundary film lubrication, the surfaces are protected by an absorbed layer of boundary lubricant, which prevents direct surface-to-surface contact and eliminates most of the surface wear.

Boundary lubrication is usually independent of the physical properties of either the lubricant (e.g. viscosity) or the bearing material (e.g. its stiffness) instead, depending almost entirely on the chemical properties of the lubricant.

Boundary film lubrication can account for a reduction of the friction coefficient by a factor of threefold to sixfold.