As long as it is maintained in the original container and unopened the answer is it will not deteriorate to any degree. if oil in a container that has to breath it will require a desiccant, maintained, dryer on the vent to prevent the egress of water. Water and oil don't store well togather..
One thing that can happen to grease especially the lighter grades is there will be an oil/base separation which will be enhanced with temperature swings. If this happens I would toss it while I've seen it partially mixed and used..
Having said that I would get with your lubrication supplier and see what the manufacturer's recommendations are. .
Kind of depends if your particular grease contains some volatiles. If a container is left open for a sufficient period of time they can evaporate. But then, what is the impact of that? And depends upon the time.
TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering
it depends on the type of product. both grease and fluid lubricant can be stored for years as long as they are in the original unopened container and you make sure that no water or outside dirt can enter the container.
some products may however have a more limited timespan. an example is an open gear lubricant that contains a volatible component to ease application. other examples are metalworking fluid concentrates (soluble oil)that usually need to be stored indoors to prevent exposure to frost. there may still be other products that have a limited timespan - you better check with your supplier.
once the container has been opened a period of half a year is a safe measure (as long as you keep water and dirt out) and that period may again be smaller if the lubricant contains volatile components or are hygroscopic (eg brakefluid).
the oil/grease separation as mentioned (bleeding) does not render the grease unfit for further use, the oil separated from the grease can usually be taken into the grease structure again by flattening the surface in the container - preferably with a suitable spatula (not wood or metal). it is a good idea to keep the grease surface in the container as flat as possible to prevent excessive bleading with a follower plate.
The additives in certain oils will separate out, similar to the grease issue described above. It not a bad idea to rotate the barrels occasionally to prevent this and/or to re-emulsify the additives. If in doubt, send a sample out to get tested before using it. Oil sample test = ~$30, Barrel of oil = ~$700, machinery it goes in = ?. As above, the manufacturer will/should be more than happy to answer all of your questions, or you need a new supplier.
