Oiler

An oiler is a person who applies oil to machinery to lubricate moving parts, or a device used for that purpose. The function is to reduce friction, wear, and heat buildup, thereby extending equipment life and maintaining performance.

In industrial settings, oilers inspect lubrication systems, replenish lubricants, and ensure bearings and gears receive the correct amount and type of oil. They may work in factories, plants, and maintenance shops, often as part of a broader mechanical or maintenance team. The term is also historical in steam and naval contexts: the oiler, also called a greaser, was a rating in the engine room who kept steam engines and auxiliary machinery lubricated aboard ships.

In rail and maritime work, oiler duties included oiling cylinders, pistons, crankpins, and other lubrication points, sometimes using hand oil cans or automatic lubricers as part of a lubrication schedule. As machinery has become more automated and enclosed, the job title has largely evolved into modern maintenance technician or lubrication technician, though the basic task remains.

The word oiler can also refer to a tool—a small bottle or container with a spout used to apply oil to machinery by hand.