Most materials, including lubricating greases, gradually deteriorate with time. For lubricating greases, the degree of deterioration depends a lot on the storage conditions. Under good storage conditions, the shelf life of a lubricating grease can be very long.
For example, SKF Maintenance Products guarantees the good quality of the grease during five years after the packaging date, provided that the grease is stored under the recommended storage conditions listed below.
If the packaging date is more than five years ago, it is advised to check the grease visually before using. The appearance of the grease should be good and the grease should not show signs of excessive oil separation or hardening.
For some greases a moderate degree of oil separation (typically less than 5 percent) or a slight degree of hardening during storage is natural and acceptable. All greases from SKF Maintenance Products are provided with the packaging date on the outside of the packaging.
Grease storage, storage conditions and practice:
■ SKF lubricating greases should be stored in a cool and dry indoor area.
■ The indoor temperature should not exceed 30 C (86 F), and should remain above 0 C (32 F). Do not put the grease directly near a heat source and avoid exposure to direct sunlight.
■ SKF lubricating grease should be stored in its original packaging. The packaging should not show any signs of damage like severe denting, corrosion, or moisture attack.
■ The grease packaging should be kept closed until the grease is needed for use. After use the packaging should be closed immediately, and kept closed.
■ When opening the grease package, do not let any dust or dirt or moisture enter the grease package. Even a small amount of dust or moisture will severely deteriorate the grease quality. Wipe lid or cover clean before opening. Use clean tools and equipment when handling or pumping the greases. Put lid or cover on a clean and dust free place.
■ If a small amount of oil has separated, it is advised to pour this oil off. It is also possible to mix the oil back into the grease, but take utmost care to apply a clean practice.