What Is Anti-Seize? | Compound That Frees Stuck Parts

That stubborn exhaust bolt that won’t budge or the rusted spark plug that snaps off during removal is exactly the problem anti-seize prevents. Unlike standard grease that thins and oxidizes under heat, this metal-infused compound creates a permanent barrier between threaded surfaces. The solid particles—typically copper, aluminum, nickel, or graphite—fill microscopic imperfections in the metal, blocking corrosion and reducing friction without ever drying out.

How Anti-Seize Works

When you apply it to threads, those metal solids embed into the surface pores, creating a protective layer that prevents oxygen and moisture from reaching the base metal. This stops galvanic corrosion between dissimilar metals—like a steel bolt threaded into an aluminum brake caliper—and eliminates the metal-to-metal welding called galling.

Where You Should and Shouldn’t Use It

Anti-seize belongs on static or slow-moving assemblies that must come apart later—fasteners, bolts, nuts, studs, and spark plugs. It’s essential for exhaust manifolds, turbocharger bolts, marine fittings, and any application where dissimilar metals meet. A thin film of roughly 0.1mm is all you need on the threads where the fastener contacts the nut or mating surface.

Where anti-seize does NOT belong: Never use it on caliper slide pins, bushing presses, or any moving mechanical assembly that requires regular lubrication. Anti-seize reduces friction dramatically, which can alter clamp load on torque-critical fasteners. For brake work specifically, our tested roundup of best anti-seize for brakes details which compounds work safely on which brake components.

Types of Anti-Seize by Temperature and Metal

Choose the type based on your specific heat and corrosion environment. Nickel-based compounds are preferred for dissimilar metals in high-corrosion settings where copper might react with aluminum.

How to Apply Anti-Seize Correctly

Clean the threads thoroughly to remove any oil, grease, or old compound. Apply a thin layer (approximately 0.1mm) only to the threads that will engage with the nut or tapped housing—avoid coating exposed threads that will remain visible after assembly. Wipe off any excess after tightening; exposed compound attracts debris that can damage threads during future removal.

Critical torque adjustment: Anti-seize dramatically reduces friction, which means your wrench applies more clamping force at the same torque setting.

Common mistakes include over-applying (a thick coating attracts contaminants and does nothing extra), ignoring the torque reduction, using standard grease where anti-seize belongs, and selecting copper-based compounds when nickel is needed for corrosion resistance. CRC Industries’ World Anti-Seize line provides specialty formulations for threaded parts across automotive, marine, and industrial applications.