The Importance of Different Types of Lubrication
Understanding the different types of lubricants is essential for choosing the right one for your application.
Choosing the wrong type of lubricant can lead to unexpected breakdowns, downtimes and potential machine failure. This is because different types of lubricants contain different additives and dispersants, leading to different viscosities, temperature regulation and specialised properties. Different applications, for example, engines and refrigerators, would require different types of lubricants due to their varying requirements and conditions.
Generally, however, all types of lubricants provide the following functions:
- Reduce friction between moving parts
- Prevent the effects of wear
- Protect against corrosion and oxidation
- Regulate temperatures
- Keep incontaminants away from key parts
- Transmit power
The 4 Different Types of Lubricants
The 4 main types of lubricants range from oils, greases, dry lubricants and penetrating lubricants. Here we explore these main categories of lubricants:
Oils are the most common types of lubricants and are typically extracted from plants. Sometimes, extra additives are added to them to prevent corrosion and oxidation. Oils come in different weights or viscosities; the lower the weight number, the thinner the oil.
When to Use Oils
- On bearings, hinges, general tool maintenance, blades
- When the lubricant needs to provide very little resistance to the moving parts
- For easy and quick lubrication without dismantling a machine
When to Not Use Oils
- When the machine part is dirty or dusty, as this will cause the oil to “gum up”, leading to added resistance. This can also cause low viscosity oils to run or drip.
- If the machinery part is to be exposed to water, as most oils are not water-resistant. This leads to water-washout of the lubricant.
Greases are manufactured by mixing oils with a thickener, and sometimes with other lubricants such as PTFE. Greases provide similar levels of lubricity as oils with increased adhesion to surfaces.
When to Use Greases
- When the lubricant needs to adhere to the surface for a long time
- On bearings, chains, gears and linkages
- Applications that require long-term lubrication
- For sealing out dust particles and water droplets
When to Not Use Grease
- On fast-moving or delicate machine parts, as greases could slow them down by creating too much resistance
- When moving machine parts are exposed and the area needs to be kept clean, as the grease can get flung around
Dry lubricants are made up of fine particles that make them extra slippery. They can come in spray forms, mixed with water, alcohol or other solvents that evaporate away, leaving a thin layer of lubricant. Anti-friction coatings are a range of last-generation products framed in dry lubrication.
When to Use Dry Lubricants
- On hinges, threaded rods, locks
- On high temperature or pressure applications, which would oxidise typical oils
- When you need to avoid a lubricant that attracts dust or dirt
- When the surrounded surfaces need to be kept clean
When to Not Use Dry Lubricants
- When the application is exposed to solvents or liquids that can wash away the remaining lubricant
Penetrating lubricants are low-viscosity and are used mainly to infiltrate small cracks over the surfaces, to increase lubrication and to split up the rust.
When to Use Penetrating Lubricants
- When machine parts have corroded or rusted for a long time and require loosening up
- On nuts and bolts
- For removing adhesive stickers, chewing gum or general warehouse tasks.
When to Not Use Penetrating Lubricants
- For any application requiring long-term lubrication
- On bearings or other key machine parts, as this could damage them.
Pastes contain high levels of lubricating solids, in addition to a carrier oil that delivers those solids to the surface where lubrication is required.
When to Use Pastes
- On threaded connections, slides, guides and tracks
- For use in extreme temperatures and high loads
- Low to moderate speeds
When to Not Use Pastes
- If the thread is already damaged or cross-threaded
- On calliper slide pins or bushing presses
Dispersions are micronised solid lubricants suspended in a lubricating fluid.
When to Use Dispersions
- When it is necessary to apply solid lubricants in liquid form to running units
- For lubricating inaccessible spots
- On chains
When to Not Use Dispersions
- When solid lubricants would interfere with the function of the machinery.
Discover our full range of industrial lubricants, as provided by our top lubrication brands Molykote, Krytox and KAJO, to find the most suitable lubricant for your industrial application. In addition, learn how to avoid lubricant washout and choose the right bearing lubricant.