Lubrication is critical for the operation and maintenance of most equipment and machinery. Lubrication reduces friction in areas of metal-to-metal contact. Greases can be used in non-sealed systems, as it will not run out like liquid lubricants can.
Greases coat and lubricate moving parts to reduce friction, heat and wear. Additionally, some greases contain agents that protect against corrosion and other damaging elements. Without lubrication, machinery parts can seize up and break down. There are many varieties, so it’s important to know which one is best for your application.
Greases are made up of three components:
1. Base oil – Typically, this is mineral or petroleum oil, which is sufficient for most applications. However, applications that involve extreme hot or cold temperatures are often better served by greases using a synthetic base oil.
2. Thickener – Many greases use a metallic lithium soap as a thickener. These soaps can include a number of ingredients, such as sodium, bentonite clay, aluminum and calcium. An agent is sometimes added to the thickener to increase its performance. Some greases use thickeners like silica or bentonite instead of soap. These do not melt in high-temperature applications.
3. Additives – These are often added to augment certain properties of the grease or add new properties that improve performance. For example, additives that inhibit rust and oxidation are common.
Additives in different greases may not be compatible with one another. When you pump fresh grease into a system, for example, continue pumping until all the old grease is forced out through the seals and other areas of the system. This prevents any incompatibility between additives in the old and fresh grease that may degrade performance.
When choosing a grease, you may notice the Timken rating on the label. This rating is based on an industry-standard test developed by the Timken Company that measures the load-bearing capacity of greases.
A Timken tester is a device with a load arm that holds weighted plates. These plates are gradually added to the load arm to increase pressure against a metal test dowel or block that is forced against a spinning bearing race. When the bearing seizes under the load, the lubrication in the grease has completely failed. The Timken OK Load is the highest load that does not cause any damage to the test dowel or block, but only light, uniform wear.
With a Timken Demonstration Tester, typical lubricants can withstand two or three weighted plates before failing. Greases formulated for extreme conditions or applications can withstand higher weight loads.
Aerosols - Aerosol greases are used for lubrication in hard-to-reach areas that do not have a grease fitting for lubrication, eliminating the need to disassemble machinery to lubricate it. Some spray out in a thin fluid and then thicken; others spray out pre-thickened. Aerosols are easy and convenient and are useful for door hinges, latches, window mechanisms, cables, chains, locks, industrial bearings and more.
Grease Guns - Grease that comes in bulk containers or cartridges are typically applied with a grease gun attached to a grease fitting. This results in a more precise, localized application than aerosols, with less waste. Grease guns are ideal for many automotive applications, factory machine components, heavy-duty equipment and more.
Hand application - Grease that comes in squeeze tubes, tubs or bulk containers can be applied by hand if needed, especially if a grease gun can’t be used. Check the product’s Safety Data Sheet prior to handling to make sure it won’t cause skin irritation. Protective nitrile gloves are recommended.
Many greases on the market are appropriate for general purpose use, which means they perform well for most automotive and industrial applications under normal conditions. However, some greases are made for applications or conditions where general purpose grease will fail.
Food service – If you work in a food service environment, it can be important to look for food grade grease, which is formulated for use on machinery that may come into direct contact with food. Examples include Glide 2 Food Grade White Grease and Motive Power Crystal Synthetic Grease. Both products are NSF-registered and rated H1 for incidental contact. While these greases are approved for food service, other greases with multiple applications may also be certified for food service use. Be sure to check the labeling.
Extreme conditions – Many greases are made to hold up in temperature extremes, environmental stresses or extreme-pressure operations. Look for a grease that’s formulated for your specific situation.
- Temperature - Some greases are formulated to withstand extreme temperatures without melting, running, dripping or drying out. Ultra Guard 2 Extreme Grease, for example, can withstand temperatures up to 550°F. Ultra Guard 2 Extreme Winter Grease is formulated to pump easily and perform well in temperatures as low as -35°F but also works well in extremely high temperatures.
- Moisture – Boating and other marine applications require grease that can resist full immersion in water without washing out. A grease like Motive-Power T.E.F. resists water and performs well under extreme pressure and in high temperatures. A grease that works well in marine applications may also be suitable for use with snow removal equipment and other machinery operating in high-moisture environments.
- Extreme Pressure – For extreme-pressure applications, look for a grease with a very high Timken load. For example, Motive-Power Extreme Pressure Gold Grease is made to lubricate bearings, chains, gears, rollers, shafts and more. Moly grease is a popular choice for extreme-pressure metal-on-metal applications because it contains molybdenum disulfide, which maximizes friction resistance and provides an extremely smooth surface. In addition, it resists corrosion, rust, oxidation, acids, moisture, salt spray, steam and dirt.