Definition
A specialized lubricant applied to the threads of bolts, studs, and fittings to prevent them from corroding, galling, or fusing together so they can be removed cleanly later. Antiseize compounds typically contain finely divided metallic particles such as copper, nickel, or aluminum suspended in a grease carrier, and are commonly used on spark plug threads, exhaust system fasteners, and other components exposed to high heat or dissimilar metal contact.
Plain English
A grease-like paste smeared on threads before assembly so the parts won't lock up or rust together and can be unscrewed again later without damage.
Context Anchor
Seen in aircraft maintenance instructions for parts such as spark plugs, exhaust hardware, and other fasteners exposed to heat or corrosion.
Derivation
From 'anti-' (against) and 'seize' (to lock up or jam). The name describes exactly what it does: it prevents seizing.
Why Pilots Care
Allows safe disassembly of critical engine parts without breaking threads or requiring destructive removal techniques.
Intuition Check
Do not read “seize” as “grab” or “confiscate” here. In maintenance, a part has seized when it is stuck so firmly that it may be damaged during removal.
Example Sentence 1
The mechanic applied a light coat of antiseize compound to the spark plug threads before installing them in the cylinder head.
Example Sentence 2
Exhaust manifold bolts received antiseize compound to ensure they could be removed during the next inspection.