What is grease

But why use grease over oil? Greases are better for leakage control and provide better seals against contaminants. Grease can remain in equipment longer and tolerate a variety of conditions. It is also easier to apply in most industrial settings. The best greases should tolerate some contamination, resist leakage and change in consistency and be compatible with all seals.

Of course, oil has advantages as well. It also provides better cooling properties. Possible if sealing system is adequate. Use for high-speed application Limited. Contaminant removal No. Continual removal by filtration or centrifuge.

Cooling efficiency No cooling capacity. High cooling capacity. Toggle navigation Toggle search. Magazine Subscribe Today! Current Issue Archive Advertise. Grease Anatomy As this definition indicates, there are three components that form lubricating grease.

Figure 1. Grease Anatomy Base Oil Most greases produced today use mineral oil as their fluid components. Thickener The thickener is a material that, in combination with the selected lubricant, will produce the solid to semifluid structure.

Additives Additives can play several roles in a lubricating grease. Table 1. NLGI Consistency Function The function of grease is to remain in contact with and lubricate moving surfaces without leaking out under the force of gravity, centrifugal action or being squeezed out under pressure. Applications Suitable for Grease Grease and oil are not interchangeable. Grease is generally used for: Machinery that runs intermittently or is in storage for an extended period of time.

Functional Properties of Grease Grease functions as a sealant to minimize leakage and to keep out contaminants. Fluid level does not have to be controlled and monitored. Characteristics As with oil, grease displays its own set of characteristics that must be considered when being chosen for an application. The characteristics commonly found on product data sheets include the following: Pumpability Pumpability is the ability of a grease to be pumped or pushed through a system.

Water resistance This is the ability of a grease to withstand the effects of water with no change in its ability to lubricate.

Consistency Grease consistency depends on the type and amount of thickener used and the viscosity of its base oil. Dropping point Dropping point is an indicator of the heat resistance of grease. Oxidation stability This is the ability of a grease to resist a chemical union with oxygen. High-temperature effects High temperatures harm greases more than they harm oils. Low-temperature effects If the temperature of a grease is lowered enough, it will become so viscous that it can be classified as a hard grease.

References 1. Pirro, Wessol. Lubrication Fundamentals. New York: Marcel Dekker, About the Author. Jeremy Wright. Related Articles. How to Minimize Grease Bleeding. Featured Videos. Atten2 S Oil Wear 2. Featured Whitepapers. Does water ingress have to be the end of your oil's life? Neural Network Detection of Machine Faults. Cement Industry Contamination Solutions. Buyer's Guide. Grease Guns. Cleaners and Degreasers.