What is Tungsten Disulphide and how its crystal structure differs from other solid lubricants?

Tungsten Disulphide, also known as WS2, is a synthetic powder with chemical formula WS2. The microstructure of WS2 crystals is a layered hollow sphere with hexagonal crystal clusters, lamellar lattice structure, whose layers are bound by weak Van der Walls Forces. This weak binding force is easily shared between the layers, resulting in a very low coefficient of friction. Tungsten Disulfide is one of most lubricious materials known to science.

Why tungsten disulfide dry film lubricant is a widely accepted coating of choice?

There are some factors that make tungsten disulfide the coating of choice in many applications including spaceflight, aerospace, military, semiconductor, medical device, automotive and more. Tungsten disulfide lubricant possesses certain significant advantages over many other classic inorganic solid lubricants; some of the attributes are listed below.

  • Components with a Tungsten Disulfide Coating can achieve a coefficient of friction as low as 0.03 dynamic and 0.07 static.
  • Tungsten Disulfide Coating is compatible with a wide temperature range, at atmospheric pressures it can withstand temperatures of -450degF to +1200degF and in vacuum atmospheres, the temperature range is -305degF to +2400degF.
  • Additionally, tungsten disulfide coating can withstand extreme pressures, up to 300,000 psi in some applications. Tungsten Disulfide Coating is virtually non-outgassing in vacuum environments.

Micro Surface Corporation utilizes WS2 per Process SL-39 in the coating process

At Micro Surface Corporation in San Jose, CA, we offer premium tungsten disulfide coating services utilizing our proprietary WS2 per Process SL-39. Tungsten Disulfide Coating is applied using state of the art equipment by our skilled technicians.

A Brief on the Coating Process

The tungsten disulfide coating process is performed at room temperature and requires no resins, binders or curing. Once the WS2 is properly applied, it will not crack or peel and becomes a part of a substrate. With the dimensional build up of only 0.5 microns (0.00002”), tungsten disulfide will not affect normal machine tolerances, making it the lubricant of choice for many precision applications such as:

  • Radial ball bearings
  • Linear bearings
  • Gears
  • Assembly fasteners
  • Pistons

Besides the above listed applications, the lubricant is applicable to many more applications where the reduction of friction and wear, elimination of galling and fretting and service life extension are desirable.

Coating Specifications

Appearance Rhodium
Silver Grey
Substrates All ferrous or non-ferrous metal
Man-made solids & plastics
Coefficient of Friction Dynamic 0.030
Static 0.070
Non Stick Excellent
Food Contact No
RC Scale 1.0 to 1.5
Flexibility Excellent
Applied Thickness 0.00002 Inch
Applications Chucks, Collets and Tools
Circuit Breakers and Switches
Compressors and Rheostats
Cryogenic Pumps
Electrical Connectors
Engine and Drive Train Parts
High Vacuum Applications
Machine tools, Pins, Taps
Magnetic Heads
Pilot Valves, Chain Saws
Rubber Gaskets, “O” Ring Seals
Seamer Rolls
Slide Mechanisms
Cure Time No cure time is required when applied at ambient temperature
Compliances Military Spec DOD-L-85645 & AMS2530

Environmental Specifications

Relative Abrasion Resistance Low
Relative Load Carrying Same as substrate up to 100,000 PSI
5% Salt Spray Rating Impervious to Fuels,Solvents Minor Decay
Ambient Temperature Range -273 to 650 ºC
Vacuum Temperature Range -188 to 1316°C at 10-14 Torr
Relative Chemical Resistance Good
Chemical Stability Inert, non-toxic, corrosion resistant
Vacuum Environment -188°C(-350°F) to 1316°C (2400°F) temperatures at 10-14 Torr
Lox Compatibility Insensitive to detonation by or in the presence of oxygen
Corrosion Resistance Minor deay of corrosion, Will not prevent corrosion of the substrate
Compliances Military Spec DOD-L-85645 & AMS2530

Material Specifications

Composition Modified Tungsten Disulfide (WS2) in Lamellar Form
Carrier High velocity refrigerated air, no binders or adhesives
Adhesion Mechanical (Molecular Interlock)
Magnetism Non-magnetic
Hardness Approximately 30 Rockwell C
Molecular Weight 248.02
Density 7.4 gms/cc