NGK Anti - Seize?

[Pete]

The use of a copper base anti-seize compound for spark plugs has been common for many years.
Copper is an excellent conductor of heat and electricity.
On spark plug threads it will help dissipate heat even if the main amount of heat is conducted through the washer.
Being copper based it provides excellent electrical conductivity for the plug current which in a race engine can be many amps.
Torque values for spark plugs will vary slightly depending on the thread size, length and the seat type. (washer or taper)
When installed with antiseize that value is usually reduced by 30%.
In rare cases it has been noted that the more efficient heat transfer with antiseize applied to the spark plug threads, the heat range needed to go hotter one notch.