I have my turbo completely dissected and I am not a big fan of regular bolts on exhaust manifold/turbo parts. They get hot/cold and break off or the bolt head strips out. Of course I broke 3 off Anyhow here are my options:

[*]Hardened Hex Bolt 10.9 ($1.45)

[*]Socket Head Cap Screw (allen) 12.9 ($1.15)

[*]Socket Head Cap Screw (allen) Stainless ($2.00)

Prices were for one size bolt that I remembered comparing. I went ahead and got #2 since they were cheapest but mainly because they were 12.9 grade. I stared at the stainless ones for 5 min but I am not sure how they would compare with the 12.9 allen screws in the long run of exhaust manifold abuse. Anyone know how they would all compare for the application I am using them for?

I have used the 12.9 allens in the manifold before for a temporary turbo application and they held up perfect but they weren't on very long.

Stainless should hold up to the exhaust manifold stuf rather well... As for me I would of taken the normal hex head bolt... I just seem to have a bad time concerning allen head cap screws...

Exhaust bolts are made of a different metal which makes them less prone to heat related breakage, they have a special coating on them, I used o know the term but forget those small details. You will have a nightmare getting the allen headed bolts out as they rust and corrode to an odd size and will most likely rust in solid and strip out inside. Bottom line...Exhaust hardware should be used versus normal hardware.

Exhaust bolts are made of a different metal which makes them less prone to heat related breakage, they have a special coating on them, I used o know the term but forget those small details. You will have a nightmare getting the allen headed bolts out as they rust and corrode to an odd size and will most likely rust in solid and strip out inside. Bottom line...Exhaust hardware should be used versus normal hardware.

:thumbup2:

i believe i would call cummins and get some from them!

Well for the last 5 months and 7000 miles my turbo has been held on by two grade 5 bolts and two studs. So far it hasn't fell off and the last I knew, I bolts were still there. Not to say they won't break down the road, just telling my experience.

My personal choice would be to look for a Good Grade of SS hex bolts. I have a rust problem on my truck & when hardware comes off (expecting it will cost extra to remove/drill it out/etc) I plane to get the mechanic to use SS on reassembly, in case it ever needs to be removed in the future. Exhaust manifilds (water jacketed maraine wet exhausts) used to have SS studs & brass nuts... back before the universal negation of quality.