What’s the difference between regular grease and lithium grease?

Mechanical equipment and systems require effective lubrication from oil, grease and fluids to operate properly and have a long active service life. Without lubrications, parts can’t move freely, and friction leads to wear and damage. Systems also become contaminated and clogged and at risk of corrosive forces like rust.

From a simple door hinge to the most complicated heat transfer system, this rule remains true.

While oil is the most common lubricant, it is not a fit for every application. Leading lubrication manufacturers like Mobil and Aeroshell, among others, offer a range of grease products that can present a more effective alternative.

Grease is a product formulated for moving parts that do not require regular lubrication, or in applications where liquid oil is unable to remain in place (for example, on rolling element bearings). Two well-known grease types are regular grease and lithium grease, and here we define them and the differences that set them apart.

What is regular grease?

Standard grease is a lubricant that is more viscous than oil and is available in different consistencies.

In terms of composition, it has three different parts: a base oil, a thickener – which makes it more viscous – and additives that enhance or suppress characteristics in the base oil.

The base oil comprises the largest part of grease and is typically between 80 to 90 per cent of the lubricant. The thickening agent then makes up about 10 to 15 per cent and performance additives are just five to 10 per cent of the lubricant.

The base oil plays a critical role in lubrication and the thickening agent determines the product’s physical characteristics. In simple terms, the consistency of grease is impacted by how much thickener it contains.

Finally, the additive package improves the operating ability of the grease.

Regular greases, especially clay-based greases, are known for their conductive properties and ability to endure at higher temperatures and extreme pressure. For example, they can withstand much higher temperatures than lithium greases, which makes them more suitable for use in for high-heat operating environments.

As a result, they are typically found used in an industrial setting and, in many cases, regular grease is referred to as industrial grease.

In fact, there are industrial-grade greases that are tailored to meet specific applications and industries. Temperature extremes, speed and moisture, for instance, may all need different thickener types.

What is lithium grease?

Lithium grease is also made up of a base oil, thickener and additives. It differentiates from regular grease by using lithium soap as a thickening agent.

In terms of its capacity as a thickener, lithium has a structure that can hold oil in place. It acts like a sponge and releases oil gradually during operation.

Grease with lithium as its thickener is a commonly selected solution due to its excellent performance at high temperatures and its water-resistant properties. Lithium grease is also relatively inexpensive to manufacture.

Lithium grease is regarded as a multipurpose grease because of its high viscosity, durability and stability. It is formulated to supply long-lasting protection from oxidation, wear and tear, extreme temperatures and corrosion.

Lithium, along with lithium complex grease, is also characterised by its outstanding lubrication, ability to generally withstand shock loads and high pressures, and its resistance against water.

The versatility of lithium grease makes it suited to a variety of different applications. These include household, gardening, automotive, industrial and more demanding metal-on-metal applications.

To sum up, regular grease is often used to refer to more industrial-grade greases that are developed to handle high temperatures and extreme pressure. These attributes are examples of why it might be selected over lithium grease.

A good all-rounder lithium grease has many useful characteristics, but sees more frequent use in moderate conditions, which it is better suited for. For instance, a lithium grease can offer excellent protection for hinges to stop them becoming rusted, but is unlikely to perform well in an extreme industrial operating environment.

Put simply, regular grease is a more suitable choice to lubricate heavy-duty machinery, and the more versatile lithium grease can be applied as a multi-purpose solution for everyday lubricating tasks.

Equipment operators seeking the right grease for an application will find a dizzying list of products to pick from. It is always considered the best policy to use a grease lubricant that is recommended by your original equipment manufacturer (OEM) or a reliable lubricant distributor. However, it is important to cross reference your selection against onsite operating conditions, performance requirements and environmental legislation before purchasing.