How to choose the best grease for every application
From axles to bearings, grease keeps your equipment’s moving parts running smoothly. Grease, unlike oil, is a semi-solid and viscous lubricant that stays in place. It is used in machinery applications when you need not only a lubricant, but a seal to keep out dust, dirt, water, and other contaminants.
Selecting the correct grease will optimize friction and wear resistance, leading to longer component life, reduced downtime, and lower operating costs. Many factors go into the selection of an appropriate grease, such as operating loads, temperature, speed, and environmental conditions.
What makes a good grease?
When selecting a grease, you must consider the application and operating conditions in which the grease will function. For a better understanding of what goes into a good grease, concentrate on its three components: base oil type, thickener type, and performance additives.
Base oils
The base oil used to formulate greases is usually mineral oil, synthetic, or a combination of the two. Grease base oil viscosity is important to know as it determines the combination of speed and load the grease can handle in the application. The base oil type and viscosity also influence the temperature range of the grease and its ability to meet special demands, such as biodegradability and food grade requirements.
Thickeners
Thickeners form the “body” or “backbone” of the grease by providing a fibrous, sponge-like structure that holds the other components in place, giving the grease consistency and the ability to stay put. The properties of the thickener influence several important performance aspects of the grease, including thermal and shear stability, resistance to contaminants, flow behavior, and load-carrying capacity.
This means that when selecting grease for any application, careful consideration to thickener technology is needed, in addition to selection of base oil type and additive content.
Performance additives
Many different types of additives are used in greases to impart specific properties to the finished product. Additives help limit the effects of adverse conditions such as heavy shock loads, wear, rust and corrosion, and oxidation.
Matching the right grease to the job
With so many factors to take into consideration and different types of greases to choose from, selecting the right one for your application can be confusing. Here are some things to keep in mind when selecting a grease for each application.
Heat resistance
High temperatures can cause grease to soften and flow away from bearing surfaces, resulting in oxidation or carbonization. A grease combining complex thickeners and synthetic oils is best for hot applications.
Resistance to water and contamination
Grease protects from corrosives. However, if the grease is not adequate, surfaces can corrode, contaminating the grease and leading to reduced lubrication capability. The treat rate and type of thickener determine a grease’s ability to act as a barrier to fluids and contaminants.
Shear stability
Applying shear forces to a grease over time usually reduces a grease’s consistency. Typically, high-speed bearings have low loads and require low viscosity. Excessive viscosity will lead to internal heat generation and increased energy consumption.
Pumpability
The ability for grease to flow under pressure through the lines, nozzles, and fittings of the grease dispensing system is important for cold temperature applications and centralized grease systems.
Load-carrying capacity
Bearings operating under high load need a grease with an adequate protective film layer that supports the load and minimizes wear. Typically, low-speed, high-load applications require a higher viscosity base oil.
Maintenance intervals
Over time, the base oils and additives in grease become depleted, causing increased wear of bearing surfaces. As a result, regular maintenance is required to replenish the grease.
Cleanliness requirements
Food- or pharmaceutical-grade greases must satisfy requirements imposed by the Food and Drug Administration and other regulatory agencies.
Types and classifications of greases
Greases are most often classified by the three primary types of thickeners:
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- Simple soaps (e.g. lithium-12 hydroxystearate)
- Complex soaps (e.g. lithium complex, aluminium complex, calcium-sulfonate complex)
- Non-soap thickeners (clay and polyurea)
Other classifications may include base oil type, industry, environment, or inclusion of additives.
Lithium grease
Lithium grease is the most widely used multi-purpose grease. It is commonly used in automotive wheel bearings and chassis applications. It also has many industrial applications such as bearings in compressors, fans and pumps, and home electric products. It is typically used where operating temperatures and loads are moderate.
Phillips 66 Dynalife® Product Line
All of the Phillips 66 lithium greases have a solid foundation of corrosion inhibition, extreme Pressure, and anti-wear performance, with different options available in base oil viscosity and consistency, to meet variations in application speed and grease distribution methods.
Lithium complex soap greases
Lithium complex thickened greases were developed to meet the increasing demands on lubricants required by machines and vehicles operating under the most severe conditions. Lithium complex greases have improved properties compared to lithium greases, including excellent pumpability over a wide range of temperatures, as well as improved thermal stability and load carrying capacity.
Typical applications include a wide range of plain and roller bearings, wheel bearings, electric motor bearings and fan bearings. It has become the most widely used grease in the U.S.
Phillips 66 Multiplex® Product Line
All of the Phillips 66 lithium complex greases have a solid foundation of corrosion inhibition, extreme pressure performance and anti-wear protection, with different options available in base oil viscosity and consistency, to meet variations in application speed and grease distribution methods. Greases based on synthetic base oils offer a very wide temperature range and high thermal stability.
Molybdenum (moly) grease
Moly grease contains molybdenum disulfide as an additive and is used for industrial and specialty applications that require a grease suitable for oscillating movements and frequent starting and stopping. Typical applications include pins, bushings, turntables, and slow-moving bearings.
Phillips 66 Megaplex® Product Line
All of the Phillips 66 moly-containing lithium complex greases have a solid foundation of corrosion inhibition, extreme pressure performance and anti-wear protection, with different options available in base oil viscosity and consistency, to meet variations in application speed and grease distribution methods.
Calcium sulfonate soap grease
This grease has excellent thermal stability, water resistance, and load carrying capabilities. It offers extraordinary corrosion protection for use around fresh or saltwater. It is commonly used in automotive, agricultural, food, mining, and steel mill applications. This grease is typically an upgrade to other multi-purpose greases such as lithium and lithium complex greases.
Phillips 66 Omnigard® Product Line
These greases’ functional structure and performance attributes provide a single multi-functional platform which can replace multiple greases and thus decrease complexity, avoid compatibility issues, and reduce cost.
Polyurea-based greases
Polyurea thickeners are polymer based and can be tailored in many ways to meet specific demands. For example, these polyurea greases can be tailored to meet specific shear stability or flow behavior requirements. They are commonly ash-less and exhibit inherent oxidation-resistant properties, allowing them to handle high temperatures and high speeds over long time periods. Typical applications include sealed-for-life wheel bearings, electric motor bearings, and fan bearings.
Phillips 66 Polytac® Product Line
All of the Phillips 66 polyurea greases have a solid foundation of corrosion inhibition and anti-wear performance, with options available for extreme pressure and lower consistency, to meet variations in application load and grease distribution methods. These greases target high-speed applications.
Aluminum complex soap greases
These greases have excellent oxidation resistance and good water resistance, but relatively
low thermal resistance. These greases are typically used for food-grade applications.
Phillips 66 Food Machinery Grease
Our premium quality aluminum complex grease was developed for use as a lubricant in applications where there is the potential for incidental food contact. It is recommended for use in food plants, bottling and packaging equipment, and other industrial applications requiring a non-staining, EP white grease.
Bentonite clay-thickened grease
The addition of bentonite clay creates a non-soap grease that does not lose its structure even at extremely high temperatures. However, its applications are limited because it offers poor corrosion resistance and have poor high-speed performance.
Our water-resistant, adhesive, clay-thickened EP grease is ideal for use in kilns, dryer ovens, cement plants, steel mills, and other heavy-duty industrial machinery operating at very high temperatures.
