Anaerobic adhesives are methacrylate liquids kept uncured by dissolved oxygen. Once confined in a thread, press fit or flange, oxygen is cut off and metal ions on the surface start the cure. They lock and seal threads, retain bearings on shafts, seal pipe threads and form gaskets. Plated, stainless or anodized parts are less reactive and usually need an activator, and wide gaps cure slowly or not at all.
Bearing's a slip fit, so wipe the shaft and use the anaerobic retaining compound, not a sleeve.
The bottle comes half full and made of air-permeable plastic on purpose, because oxygen keeps the liquid stable; never decant it into a metal or glass container.
Also heard as
- anaerobic
- anaerobic sealant
Related terms
Threadlocker
An anaerobic adhesive applied to fastener threads to stop them loosening from vibration.
Activator
A liquid applied to one surface to speed or start the cure of an adhesive placed on the other.
Oxygen inhibition
Air at the surface blocking the cure of free-radical adhesives, leaving them sticky where exposed.
Blue
Shop shorthand for medium-strength threadlocker, the removable kind; red means the permanent kind.