At what size do moly particles become abrasive?

Here is a tech service bulletin "Correlation between particle size and engine wear." for engine oil that might help answer your question. I imagine it may hold some truth for grease as well.

http://www.amsoil.com/techserv...0Wear.pdf?zo=1181889

Moly can be found in many forms. Some are more abrasive than others.

Thanks for the response but this article is on contaminants, whereas Moly is an additive or I guess cn be used as a straight lubricant. Fine Moly dust is good - not so sure about Moly granules...

You are welcome.

It depends on the form the moly is in and its hardness. If it is as hard as the metal and its size exceeds the film thickness, it would abrade the metal. If not, it won't.

Good moly will be 1 micron or less. This should not be abrasive so long as the product is properly formulated.

Thanks everyone for the info...

I've been told that MoS2 is abrasive when it is broken down into SMALL particles. It is the crystal structure that gives MoS2 its "slip' and makes it a solid lubricant. Once it becomes nano-sized, it is ineffective as a solid lubricant and acts as an abrasive.

The particle size is important since very fine abrasives are used to polish lenses of all types so there are no scratches. If the polish is too coarse the lens will have scratches, and if it is too fine, processing time will increase. In the polishing industry, it is very important to have a very narrow particle size distribution for maximum productivity. The disks used on computer hard drives are polished with very precisely milled abrasives. Abrasives in toothpaste are another example; they must be aggressive but not enough to remove enamel.

Thanks for everyone's post, i have learnt more on moly dust, wonderful coming.

i think it depends upon how hard is the moly particles. also the industrial moly cannot be used for the engine because 7 microns is very much. we need abrasive so have to know how it can be? some expertise related to grease can only help us.