What Are Industrial Lubricants and Grease?

With hundreds of moving and vibrating surfaces on an aircraft at any given time, unchecked friction could lead to a sudden spike in temperature and eventual mechanical failure. To prevent such an occurrence, all moveable parts of an aircraft must be properly lubricated before use. In this blog, we will discuss the types of lubricant used on aircraft to reduce friction and keep them working like a "well-oiled machine."

The most common type of lubricant employed in aviation are liquids, which are generally derived from petroleum and synthetic fluids. Such lubricants are easy to apply and, due to the large supply of petroleum on the market, economically sound. Regardless of the fluid used, all liquid lubricants generally share the feature of moderately high viscosity, which defines the frictional force between the lubricant and an adjacent structure in motion. In general, too little viscosity will allow for greater friction between two moving parts, whereas too much can cause a loss in power. Also, since high-pressure operating environments tend to increase the viscosity of liquid lubricants, aircraft call for a higher-performing fluid that can better withstand pressure changes.

Industrial grease is a semi-solid film made from a liquid lubricant base, a thickening agent, and other additives. This variety of lubricants is more resistant to sudden changes in pressure and temperature, and with the addition of certain additives, can act as an anticorrosive agent. Much like pure liquid lubricants, one can choose between the two common types of base liquids, those being petroleum or synthetic. Petroleum bases are preferred in applications where the adjacent surface is subjected to a heavy load, but they typically underperform in low-temperature situations. Conversely, synthetic-based oils maintain their performance over a broad temperature range.

Another option to consider when purchasing industrial grease is the agent used for thickening. Depending on the agent, grease can vary in texture from very soft to nearly solid. While the stiffness of the grease does not affect lubrication performance, it does affect the oil's ability to regain shape after high-pressure loads are added. While many different materials are chosen as thickening agents, they can be broadly categorized as soap-based or non-soap-based, both of which have benefits in particular applications.

The true allure that comes with using industrial grease comes from additives, which give the mixture additional properties that are beneficial to the aircraft components. Some common examples of additives include corrosion inhibitors, load-carrying additives, and anti-oxidants, among others. With any additive, the goal is to either extend the longevity of the associated components or decrease the amount of grease needed for the application.

The last category of lubricants, which are rarely found in aviation, is solid lubricants. Commonly made from synthetic or natural graphite, this film-like material can be applied to sliding surfaces like the other two lubricant classes. This material holds up very well in extreme temperature settings or in areas where using a liquid-based lubricant is unfeasible. While solid lubricants have a favorable pressure and temperature profile, their use in aviation is limited to hydraulic fittings and other bearings.

Regardless of the lubricant type chosen, it is imperative to store the material correctly. Most liquid-based lubricants are sold in bulk and stored in large drums or tanks. Additionally, their shelf life is dependent on the type of additives used and the cleanliness and temperature of the storage area. As with any material used in aviation, lubricants should be as clean as possible and free of contaminants. Regular inspection should be implemented to ensure that the material is under the ISO-regulated number of particles per milliliter before use. Also, all lubricants should be disposed of in a manner that is not harmful to the environment.

When looking to procure high-quality aircraft lubricants with rapid lead times and fair prices, choose Stacked Industrials to fulfill your requirements. As an affiliate of ASAP Semiconductor, we give customers direct access to one of the largest ready-to-purchase inventories in the industry. Additionally, with our expert team of account managers, we can help you find the exact items you need. We also offer same-day shipping options on qualifying in-stock components, making us the perfect choice for customers facing aircraft on ground (AOG) requirements. Browse our various parts catalogs or use our powerful search engine to find any part you need, and submit a quote at any time using our quick and easy Instant RFQ service.