What Is Fluid Grease?
– Fluid grease has a consistency comparable to cooking oil.
Fluid grease represents the transition between lubricating oil and conventional grease. With a consistency similar to cooking oil, it is ideal for situations where lubricating oils cannot adhere well due to high temperatures or rotational speeds.
Fluid greases are typically used when standard greases are too thick and oils are too thin to provide sufficient lubrication. They are particularly useful in industrial and automotive applications that demand long-lasting performance under challenging conditions.
Consistency and NLGI Classification
The consistency of lubricating grease is defined by the National Lubricating Grease Institute (NLGI). There are 9 NLGI classes ranging from extremely fluid (NLGI 000) to very firm (NLGI 6). Fluid greases fall into the lowest three categories: NLGI 000, 00, and 0.
NLGI Overview
| NLGI Class | Cone Penetration in 0.1 mm | Visual Assessment | Comparison |
|---|---|---|---|
| 000 | 445 – 475 | Very liquid | Speiseöl |
| 00 | 400 – 430 | Liquid | Joghurt |
| 0 | 355 – 385 | Viscous | |
| 1 | 310 – 340 | Very soft | Senf |
| 2 | 265 – 295 | Soft | Hautcreme |
| 3 | 220 – 250 | Medium firm | |
| 4 | 175 – 205 | Firm | |
| 5 | 130 – 160 | Very firm | |
| 6 | 85 – 115 | Extrem firm | Käse |
Applications of Wodoil Fluid Greases
Fluid greases are used in conditions where traditional lubricants fail to perform. Their excellent adhesion and temperature resistance make them suitable for:
- Open gears
- Closed gears
- Central lubrication systems in commercial vehicles
- Closed roller and plain bearings
Gear Fluid Grease for Open Gears
– These fluid greases must be particularly efficient:
Water-resistant, heat-resistant with high corrosion protection.
Due to the design, the fluid greases used here must fulfil special requirements.
Firstly, they must be able to adhere stably to the lubrication point in the event of water contact. These fluid greases must not drip off so quickly even at higher temperatures, which can be caused by surrounding systems, for example.
In addition, open gearboxes can quickly become contaminated and highly corrosive. This is why these fluid greases are equipped with additives that provide outstanding corrosion protection. Transmission fluid greases for open gears are often available in viscosity class NLGI 0.
Gear Fluid Grease for Closed Gears
– Stable under high heat and rotation
These gearboxes are naturally much better protected from external influences than open gearboxes. Nevertheless, wear should be avoided as far as possible. It is therefore important to choose the right fluid greases.
It may be sufficient if the gears are immersed in an oil bath and the lubricating oil is sprayed onto the surrounding gears. However, if this type of lubrication is no longer sufficient due to high rotation or heat development, fluid greases are used. These adhere securely to the lubrication points even at high rotational speeds.