Reading a grease designation (DIN 51825)
Strings such as KPF2K-10 are not random. Each part says what the grease is for, what additive it carries, its stiffness and its temperature window.
The pattern
A DIN 51825 designation is read in order: grease type, additive letters, the NLGI number, the upper operating temperature letter and then the lower temperature limit in degrees C below zero.
Reading it
| Part | Means | Example |
|---|---|---|
| K | Grease for rolling bearings, plain bearings and sliding surfaces | K at the start |
| P | Contains EP (extreme pressure) and anti-wear additives | KP… |
| F | Contains solid lubricants | KPF… |
| E | Ester-based oil, usually an environmentally accepted grease | KPE… |
| Number | NLGI consistency grade | …2… |
| Letter after the number | Upper operating temperature, from the standard's table | …K… |
| Number after the dash | Lower operating temperature limit in °C below zero | …−20 |
Worked example
KPF2K-10 reads: rolling or plain bearing grease, with EP additives and solid lubricants, NLGI 2, with an upper temperature code of K and a lower limit of −10 °C. That is a typical profile for heavy, slow machines in a plant that does not see hard frost. A cold-climate site needs a grease with a lower limit.
Use it for
- Quick comparison of two greases from different suppliers.
- A sanity check that a grease has EP additives or solids where the application needs them.
- Checking the lower temperature limit against your coldest morning.
Caution
The code is a minimum description from a standard test. It does not replace the supplier's data sheet for viscosity, load rating or water resistance.