Galling or cold welding is a form of wear caused by sliding surfaces seizing together and is a common problem with threaded fasteners that occurs when the surfaces of male and female threads are under a great deal of pressure. As the fasteners are being tightened, metal high points of the threads contact each other which increases friction and adhesion between the two and can generate enough heat to fuse and seize nuts and bolts together. If the fasteners continue to be tightened after galling has started it may strip the threads which can prevent the removal of the fastener. Tungsten Disulfide (WS2) prevents galling and seizing from occurring by reducing friction between fasteners which also makes them easier to assemble and disassemble. Galling and Seizing is also common in bearings & pistons in engines, hydraulic cylinders and motors and Tungsten Disulfde (WS2) excels at preventing it in these applications as well due to it's high operating temperature of 1,200°F and compatibility with lubricants, fuels, and hydraulic fluids.

  • Excellent at preventing thread galling and seizing on fasteners that require a high preload during assembly and facilitates easy installation and disassembly even after exposure to high temperatures.
  • Lowest thread friction values available.
  • High operating temperature.
  • Prevents galling and cold welding.
  • Compatible with lubricants, fuels, hydraulic fluids.

Tungsten Disulfide (WS2) coated stainless steel bolts have higher tension and a lower coefficient of friction compared to Xylan coated bolts.

Tungsten Disulfide (WS2) Coated Stainless Steel Bolt Tension & Coefficient of Friction

Torque: Tension: Coefficient of Friction:
50 1316 0.101
100 2750 0.097
150 4083 0.098
200 5283 0.101
250 6266 0.106
300 7116 0.112

Xylan Coated Stainless Steel Bolt Tension & Coefficient of Friction

Torque: Tension: Coefficient of Friction:
50 795 0.161
100 1860 0.138
150 3230 0.129
200 4323 0.126
250 5367 0.125
300 6458 0.126
Tungsten Disulfide Coefficient of Friction Test