Is there a particular type of Anti-Seize compound that is preferred for use on spark plugs? What temperature rating is needed?


Most people use Copper because it's the most common and cheapest, but beware the cheap/generic stuff that's only good to 600°F or so. I use the Nickel type, not so much for the temperature (2400°F), though that is a bonus, but because there are some metals that you can't use the copper on (Titanium might be one, I'm not 100% but Nickel is fine for it).

As far as temperature rating needed, according to NGK, it will depend on the hot/cold value of the specific plug, but optimal range is 500°C (932°F) and 800°C (1472°F) for the part that extends into the cylinder. The threads are on the water cooled block, so I'd expect them to hover in the 300°F - 600°F range. You can probably get away with Copper, but I'd use Nickel.

  • This Datasheet recommends Nickel for "Fasteners in continuous high heat areas", but yet also has a Graphite type recommended for Spark Plugs due to its increased conductivity
    – Ehryk
    Apr 18 '12 at 6:16
  • I'd view that as more of a luxury, like how I personally run my amplifier/deck grounds back to the battery. I've never used it, have never had issues with Nickel in the many spark plugs I've used it on, and Nickel and the actual threads conduct well enough anyway. So: if money's no issue and/or you're the perfectionist type, get the Graphite. If not, get Nickel.
    – Ehryk
    Apr 18 '12 at 6:19
  • I just use the normal autoparts store generic "anti-seize" tube (purchased about 10 years ago). I don't know what's in it, but it's silver colored and works great. No heat related problems (and I've got one 4-cyl turbo that's about the worst case scenario for heat, with measured EGTs of just over 1000C one day at the track with coolant temps at 100C and oil temps of 150C at the same time). I'd be curious to know exactly how hot it gets on the sparkplug threads, must not too terribly hot though as the plugs always come out with the anti-seize looking just fine. Apr 18 '12 at 12:40
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    Silver colored AS would lead me to speculate that it's Stainless Steel ("Silver Grade") or Nickel as the metal, both have significantly higher temps than cheap, generic copper (and generic USUALLY is copper). You have slightly upgraded generic AS, and/or a decent autoparts store owner.
    – Ehryk
    Apr 18 '12 at 13:20
  • Permatex is the brand I see most here in the US. They have three on their website. Nickel and copper, and one that doesn't state the contents in the name. But that one says it's a mix of aluminum, copper, and graphite.
    – Tim B
    Jun 19 '13 at 11:39

The highest heat range. The price difference is only a couple of bucks and you don't do the job often enough to worry about it. If you get one "oxygen sensor safe" you can reuse it throughout your exhaust system on other jobs you may have that requires antisieze compound.

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