ANTI-GALLING
COATING.

Why stainless seizes

Stainless steel owes its corrosion resistance to a thin passive oxide layer. Under the contact pressure in a thread flank that layer breaks down, and once bare metal touches bare metal the two surfaces weld together rather than slide. The result is a fastener that galls on installation, or one that cannot be removed without destroying it. Our full explanation of the mechanism is in how to prevent galling in stainless steel fasteners.

Anti-seize compound works, until it attracts grit, washes out, burns off or migrates out of the joint. A bonded coating does not: once thermally cured it becomes part of the component, and it is still there on the twentieth disassembly.

What we coat, and with what

Two families cover almost all anti-galling work, and the choice follows the service conditions rather than preference.

• PTFE and the Teflon™ family — the lowest friction coefficient and the widest chemical resistance. The usual answer for fasteners, and for anywhere moisture or chemical exposure is a factor.
• MoS₂ solid film lubricants — better under extreme contact pressure and in vacuum. The answer when pressure is the primary concern rather than chemistry.
• Hybrid systems — Lube-Lok and Lubri-Bond combine both technologies in a single bonded film, for parts that see high load and moisture. Listed on our high-performance coatings page.

The PTFE against MoS₂ comparison works through the trade-off in detail.

Parts that come through for anti-galling work

• Stainless fasteners — bolts, nuts, threaded rod, studs and socket screws.
• Flange hardware — where repeated disassembly is routine and a seized stud means cutting.
• Valve stems and threaded internals — where galling means a valve that will not actuate.
• Precision assemblies — where a galled thread contaminates the assembly with debris.

Masking threads properly

On a threaded part the masking is as important as the coating. Thread flanks that should be coated need full coverage, and bearing surfaces or sealing faces that must stay bare need protecting with something that survives grit blasting and a full cure cycle. That is what our hard masking capability is for — silicone plugs and caps for threaded and blind holes, and CNC-machined shrouds for anything more complex.

Try it on your own fasteners

Galling is easy to test and hard to argue about: coat a batch, assemble and disassemble them, and compare. Send up to 10 parts on the free sample run and we will coat them at no charge with whichever system fits the application. Call (775) 508-9225 or tell us what is seizing and we will tell you what we would specify.

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