perryinva

The pair of stove bolts on the clamp between the muffler and catalytic converter. You have to buy new clamps to get the bolts from Porsche. Have to have the rightvsquare base,

DK570

I got these last summer, they held up very well over the winter - no visible rust.
http://www.fastenal.com/web/products...ex?sku=0162168
http://www.fastenal.com/web/products...N2600000A40000

perryinva

Thanks! That is PERFECT!

Goldenwarrior1

You can buy the same stainless bolt at your local Lowes or Home Depot for about the same price and no shipping.

wyovino

I bought mine at Ace Hardware.

perryinva

Now that I know I can get Metric SS carriage bolts, and not deal with the corrosion, that's what I want. Are those at Lowes or Ace? Not here that I saw. Special section?

wyovino

Yes, Ace had stainless steel bolts that worked with the exhaust and cat clamps. Metric or standard makes no difference as long as you get the correct nut for the bolt. The clamps are not threaded.

mikeswift

Thanks to the posters for finding out what these are. I want to replace the 3 bolts that are holding mufflers in place. And the 6 bolts that hold the headers? I think thats what its called. (the pipe that splits into 3 on both sides, i think exhaust from the engine).

kgoertz

Before replacing the header bolts with stainless steel versions do a quick google on using stainless steel bolts for exhaust applications. SS bolts with SS nuts can gall when heated which means they can fuse together. They also don't have nearly the same tensile strength which means they can snap if over torqued. But for the muffler bolts and clamps the best solution is likely SS bolts with brass nuts to solve the galling problem.
At least that was my conclusion after an hour or two of reading online.

DK570

Galling shouldn't be an issue if you use anti-seize compound, which I always do on almost everything living in Wisconsin. Also, if you are able to find stainless hardware of two different crystal structures, the likelihood greatly decreases. I would be cautious of brass because it can a very soft metal that is not very corrosion resistant depending on the specific type.

heliflyer

Does anybody make a stainless clamp? No matter how I treat mine I cant stop them rusting and looking unsightly.

DrMEMS

My experience matches what you read:

After 12 years and 80+ kmi on my 996, the original bolts on the clamps between the cats and the mufflers were badly rusted. I replaced them with hex-head bolts made of Type 316 stainless steel (M10 x 55 mm long, 1.5-mm pitch) and 316 SS nuts, plus 316 SS washers. After just 2000 mi of driving, two of the four nuts were fused to the bolts. The bolts had become so soft that I sheared two of the four bolts apart without too much effort. I believe that a higher carbon content is needed for high-temperature operation.

Next I am trying high-strength Class 10.9 bolts (M10 x 60 mm from McMaster-Carr) with a blue corrosion-resistant zinc plating. Same Class 10.9 with blue coating for the nuts.

Byprodriver

High grade steel bolts are not recommended because the hardening makes them more brittle. My 37 year old Anti-seize has never failed me.
Are you by chance one of those poor individuals forced to live oceanside?

crashclint

LOCTITE Nickel Anti-Seize. Used this stuff on Mannesmann Demag and Krauss-Maffei molding machines for years. I have broken many a bolt using the copper anti-seize in high heat applications as the copper can soften fuse itself to the bolt.

Chiamac

I just go and grab something to cut or chisel them out with. When the time comes to replace them I'll again find something to cut them out with.

=)

An excuse to buy and/or have a cutting torch!