Greases are found at nearly every jobsite. Despite their popularity, many people don’t really understand how greases work or which ones they should use for different jobs.
There are plenty of different types of greases – from soap thicked mineral oils to extreme-pressure greases.
Which grease should you use? Which grease is the best option for your current job? Today, I’m going to teach you everything you need to know about grease:
Grease is grease, right? Wrong!
Using the wrong type of grease is a bad idea. Just like lubricating oil can oxidize, so can the base oil within grease. As grease oxidizes, it darkens and creates a build-up of acidic oxidation products. These products can destroy thickener, leading to serious problems like leakage, oil bleeding, and softening.
Making matters worse is the fact that grease does not easily conduct heat. This means oxidation occurs around a single “hot point” before slowly spreading across the rest of the grease buildup. Ultimately, that process produces carbonization, progressive hardening, and crust formation.
Grease also has minimum and maximum temperatures. Moving beyond either of these temperatures will reduce the grease-like consistency and provide sub-par results.
To make a long story short: caring about grease is important, and you should learn how to pick the right grease for the task at hand.
Mineral oils mixed with solids offer a powerful lubricating solution. They’re ideal for heavy machines and certain specialized applications.
Use for: Any applications which require heavy lubricants, including rough-fitting machine parts or machines which operate under heavy pressure. Mineral oils mixed with solids are typically used with concrete mixers, bearings, heavy construction equipment, and rollers on conveyers.
Extreme-pressure greases contain unique additives which improve the film strength of the material under various applications. This film strength prevents the grease from separating in extreme-pressure applications, which means you avoid metal-on-metal contact.
EP greases contain a number of different additives according to their unique applications. Popular additives include zinc, lead, sulfur, and chlorinated waxes or phosphates.
All of these additives create chemical reactions with the metal. This chemical reaction occurs when high-pressure is applied to the grease – which is why this grease is called extreme-pressure grease. This chemical reaction creates a film which further protects the metals by providing a type of cushion.
Use for: High-pressure metal-on-metal applications which require high levels of lubricating protection.
Heavy asphaltic-type oils are officially classified as greases. However, they’re more accurately labeled as thick/heavy oils.
These “greases”, like EP greases, form a protective film to facilitate lubrication. This protective film is activated when the grease is heated – but also when it’s painted on surfaces and allowed to cool.
In applications where a higher-viscosity grease is required, the heavy oils can be mixed with lighter oils to improve the pour point.
Use for: Open-type gearing and wire rope.
Most greases are classified as soap thicked mineral oils. These greases can be further separated into a number of different categories, including:
-Sodium-base: General-purpose grease ideal for lubricating machine parts which operate near heat.
-Barium-soap: General-purpose grease capable of working over a wide range of temperatures as high as 350 degrees Fahrenheit.
–Lithium-soap: General-purpose grease capable of handling extreme temperatures as low as -60F and as high as 300F
-Calcium-soap: Inexpensive grease commonly used on axles, water pumps, and many general machine applications.
-Aluminum-soap: A very sticky grease which is ideal for any application which involves surface lubrication.
Each type of grease is used for different applications. Calcium-soap grease (also known as lime-soap grease) is the most popular and widely-used of the group. It’s popular due to its wide range of applications and relatively inexpensive price.
A multi-purpose grease combines two or more of the specialized greases listed above. This allows for the use of grease in a wide variety of applications. Most jobsites use multi-purpose grease because it can be used to replace as many as six specialized greases.
Whether you’re lubricating various types of bearings or lubricating heavy machinery, greases are a necessary part of working with machines. You can view our selection of greases here.