Solid Lubricant vs. Oil Lubricant - What’s the Difference

Posted on March 30, 2021

Constant friction within bearings creates heat. Over time, this will deteriorate the bearing, significantly shortening its life. Bearing lubrication plays a vital role in separating the moving parts, minimizing friction and preventing ongoing wear and tear. As such, bearing lubrication is one of the most important aspects in maintaining and prolonging the life of the bearing. Lubricants also serve to reduce corrosion and protect against contaminants that would otherwise damage the bearings. By including inspection and regular lubrication in bearing maintenance, it is possible to improve the functionality and reliability of every bearing, reducing the risk of corrosion-based failures.

What Are the Differences Between Solid and Oil Lubricant?

There are two main subsets of bearing lubricants: solid lubricants and oil lubricants.

Solid Lubricants

Solid lubricants are oil-filled microporous polymers. They are ideal for reducing friction and preventing wear, particularly in situations where options such as oil or grease would not provide high enough levels of lubrication. Solid lubricants are also an excellent choice for areas that are challenging to access for relubrication. Common applications include: AdobeStock_316537435

There are a variety of solid lubricant options, such as:

  • Boron nitride
  • Polytetrafluoroethylene
  • Graphite
  • Molybdenum disulfide

Advantages of Solid Lubricants

In addition to providing reduced friction and wear, solid lubricants offer the advantage of permanent lubrication with no leakages. They generate low amounts of heat and offer low startup torque.

Solid lubricants are ideal for use in the food industry, as they are NSF certified for food processing. This type of lubrication will keep contaminants out, and it is compatible with acids and other corrosive chemicals. As such, it functions well in wash down applications.

Oil/Grease Lubricants

Oil/Grease lubricants are typically more popular than solid lubricants. The two most common types of oil for oil lubricants are synthetic and natural mineral oil. Most often, manufacturers will mix the chosen oil with a thickening agent to create varying viscosities and properties.

There are three properties that are vital to consider when choosing an oil lubricant:

  • Viscosity
  • Temperature range AdobeStock_119171141
  • Evaporative rate

While solid lubricants are the better choice for more permanent lubrication and hard-to-reach areas, oil lubricants are ideal for applications when bearing lube must be circulated. For example, oil lubrication functions well in transferring heat for thermal management and is a good choice for automated lube systems.

Advantages of Oil/Grease Lubricants

Compared to solid lubricants, oil lubricants are typically easier to control and keep clean. They function well at high speeds and temperatures, and offer less start up and running torque. Oil lubricants also offer the added advantage of reducing bearing noise and vibration.

Are There Specific Situations to Use One Instead of Another?

In applications where standard lubrication solutions have proven ineffective, solid lubricants are often ideal. Generally, solid lubricants are the better choice for bearings in challenging or highly corrosive environments. For example, this type of lubrication works well submerged in water and in areas that experience high levels of dust and lint.

Oil lubricants are the better choice for open bearing designs where low torque and high speed are a priority. This type of lubrication works well in areas where oil flow is available. It also works well to carry heat away from the bearing and is more affordable than solid lubrication.

Why Choose Emerson for Your Bearing Needs?

Opting for the most appropriate bearing lubricant is vital in maintaining the efficiency and safety of your facility’s machinery and overall operations. However, with so many options to choose from, it can be challenging to determine the best solution for your needs. At Emerson Bearing, our experts will work closely with you to recommend the most appropriate lubricant for your unique bearing system.

We keep all of our inventory on-site, and we offer two-day shipping to all of our customers. This ensures that you receive your order as soon as possible, which in turn will improve the longevity and functionality of your bearing system.

Partner with Emerson Bearing

For more than 50 years, we at Emerson Bearing have been meeting the bearing needs of customers around the globe. We know that every project is unique, and our experts are dedicated to working one on one with each customer to assist in choosing the appropriate solution for their application. By offering one-stop shopping and rapid shipping, we ensure that you receive your order with very little turnaround time. To learn more about our bearing solutions, contact us or request a quote today.


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