Molybdenum disulfide (MoS2 or "Moly") is a dry solid lubricant powder or a fortifying compound that is added to a wide range of materials such as greases, oils, polymers and paints. It has a planar structure that allows the molecules to easily slide past each other and create an extremely low coefficient of friction between coated surfaces.

When added to a lubricating oil or grease, it forms a chemical layer that prevents metal surfaces from touching each other, significantly reducing friction and wear and improving equipment performance life. It is also highly resistant to extreme pressure and harsh environments that would destroy other lubricants.

Graco offers several molybdenum disulfide greases that are designed to meet the severe lubrication requirements of industrial and construction equipment as well as automotive, heavy-duty vehicles. These greases are formulated with MoS2 in concentrations that range from 1 to 20%.

These greases are often used where high-pressure metal surfaces are sliding against each other, such as in bearings that experience shock loading or oscillating motion. They are also recommended for use in applications where a grease needs to resist thermal oxidation and resist the formation of galling, seizing or corrosion.

Molybdenum disulfide lubricants have been the subject of extensive research, both applied and fundamental. One reason for this is that MoS2 lubricants are able to resist the formation of a solid film that can cause galling and seizing even in environments where other lubricants fail, such as under vacuum or inert atmospheres.