ISO Greases classification
ISO 6743-9 is the International Organization for Standardization’s classification of the X ( greases) family, which is included in ISO 6743 (Lubricants, industrial oils and class L related products).
The classification in this standard is based on the conditions of use of the grease and not on its formulation.
Greases are designated by the following codes:
ISO-L-X-Symbol1-Symbol2-Symbol3-Symbol4-Class NLGI
Where:
L: grease, industrial oil or similar product
X: grease
Symbol1 – Minimum working temperature
A – 0 °C
B -20 °C
C -30 °C
D -40 °C
E – <-40 °C
Symbol2 - Maximum operating temperature
A - 60 °C
B - 90 °C
C - 120 °C
D - 140 °C
E - 160 °C
F - 180 °C
G - >180 °C
Symbol3 – Lubricity in the presence of water and level of corrosion protection
| Symbol3 | External environment | Anti-corrosion protection |
| A | dry | no protection |
| B | dry | fresh water protection |
| C | dry | seawater protection |
| D | wet fog | no protection |
| E | wet fog | fresh water protection |
| F | wet fog | seawater protection |
| G | water wash | no protection |
| H | water wash | fresh water protection |
| I | water wash | seawater protection |
Symbol4 – Lubricating capacity of grease at high loads
A Grease without anti-seize additives
B Anti-Seize Grease
NLGI class – grease consistency class according to NLGI