Steam cylinders are lubricated by introducing the lubricant into the steam line. This can be done either by using an atomiser, or by direct feed into very high temperature steam. Atomised oil mist is then carried by the steam to the point of lubrication, forming an oil film that reduces friction, and hence wear. The oil also prevents the leakage of steam past valves, pistons, etc.

Rock Oil Compounded Steam Cylinder oils are formulated from selected base oils and carefully chosen additives to provide a lubricant which is strongly adhesive to metal surfaces and also performs well under wet conditions.