user 72902

I hear you and I figure whatever you use will get heat cycled a thousand times before you try to remove it. I went with stainless figuring it would be the strongest and lest likely to snap off when removing.

dan!

If you use an anti-seize compound, then seizing hardware is a much less common occurrence:

https://www.mcmaster.com/#1820k1

StormRune

Copper coated nuts are recommended to prevent seizing on exhausts. When I last needed some, the Porsche dealer didn't have them but I was able to find them in the right size at the local BMW parts desk. You can also buy them online. I'd guess this is similar to using copper anti-seize like BER recommends, but the copper is already on the nuts.

When I researched this once I found that the grade of stainless you find at Home Depot or Lowes isn't sufficient for hot exhausts.

Bruce In Philly

I used stainless from Home Depot when I did my X-pipe. The car had 57K on it at the time.... I will be doing plugs in a few more miles at 120K (has 117K now) and I will inspect these "cheapo" Home Depot bolts then.

So far, no problems that I know of. I have trouble believing that these Home Depot SS bolts are worse than the ones installed at the factory.... those were rotted, softened, and broke after 57K miles.

Peace
Bruce in Philly

mcfisticuffs

SS for strength and corrosion resistance, with copper anti-seize.

DC911S

I went with all stainless on the bolts and the nuts that hold the header/cats to the X pipe on my 997.2. Got the Torx ones too. Go to Jegs and order them. Copper won't rust of course but I think it's too soft for that application. There is a thread in here that goes through it and what sizes you need.

BER

I do not intend to hijack this thread, but every DIY home mechanic should have a tube of Wurth CU 800 (or similiar) in their work chest.

This stuff protects up to 1200 C, which is pretty "toasty". I use on all fasteners that are exposed to very high temps...exhaust hardware, exhaust studs, O2 sensors, caliper bolts, spark plugs (yes, I know what Porsche says), etc. Never had a problem removing hardware that has been treated with this copper anti-seize, even years after the fastener was installed.

Now back to your regular scheduled programming.