What is galling?
Galling is a form of wear caused by adhesion between sliding surfaces. Galling is a common problem where metals such as stainless steel, aluminum and titanium slide while in contact with like or dissimilar metals. The interaction of the two sliding surfaces may result in the transfer of material from one sliding surface to another. Pressure builds between the surfaces and breaks down the protective oxide coatings, causing slipping and tearing of the crystal structure beneath the surface. This generally leaves some material stuck or cold-welded to the adjacent surface.
Galling often occurs in high load, low speed applications, but can also occur in high-speed applications with very little load. Galling occurs quickly and continues to spread as the raised lumps induce more galling. It often occurs in threaded surfaces including screws and bolts.
What happens when galling occurs?
Galling may cause performance failures, plus increased maintenance and repair costs.
How can one prevent galling?
Use products engineered to provide extreme lubricity. Fluoramics manufactures several products designed to reduce friction and galling. Using products with superior lubrication qualities provides for a smooth and continuous torque. This reduces maintenance and repair costs, plus down time caused by performance failures.
Tufoil Technology products that reduce friction and galling include:
  • Tufoil for Industrial Use – This is an extreme pressure lubricant classified as an NLGI 000 that provides corrosion protection while reducing friction and temperatures that cause galling. Tufoil for Industrial Use reduces maintenance and repair bills, is water resistant/displacing, and remains highly stable and resistant to thermal degradation. In particular, it improves performance of stainless steel, aluminum, titanium, copper and most metals.
  • Lightning Grease – This is an easily-sheared NLGI 2 grease that significantly lowers operating temperatures, eliminates stick slip, is anti-galling and water resistant/displacing, plus provides corrosion protection.
  • High Temperature Spindle Grease – This NLGI 1 grease lubricates and protects, is stable in excessive heat, anti-galling, water resistant/displacing, and provides corrosion protection.
Other Fluoramics products that reduce friction and galling:
  • Formula-8 thread sealant – This is an aqueous-based chemistry that will not cold flow and is stable in pressures up to 10,000 psi, Formula-8 is approved for natural gas and oxygen systems.
  • LOX-8 Paste, LOX-8 Grease, LOX-8 LD, and Chem-8 thread sealants and greases, and Full Density PTFE Tape – These are super hydrophobic, chemically-inert, oxygen-approved (with the exception of LOX-8 LD and Chem-8) products, with no cure time/non-hardening. They are ideal for repetitive assembly and disassembly. NLGI numbers range from 2 – 8.
  • HinderRUST S4.0 rust stopper and lubricant – Provides extreme surface adhesion and aggressively wets to surface. HinderRUST S4.0 is water resistant/moisture displacing and provides corrosion protection, plus is an excellent lubricant. Use as an assembly lubrication to prevent galling and protect against corrosion. Weld-through approved.

Some material for this article was obtained from https://en.wikipedia.org/wiki/Galling