Identify how the lubricant is transported
NSK describes oil mist as oil atomised into an air stream, while oil-air lubrication meters small quantities of oil into a line with a continuous flow of air.
The metering and delivery arrangements are consequently different, even though both use oil and air. A bearing arrangement designed around one method cannot be assumed to receive an equivalent lubricant supply from the other. The full system specification should identify the actual delivery method, its equipment and the bearing application it serves. A shorthand note such as “air lubrication” loses information needed to evaluate either the original design or a proposed system change.