While I have the head off I'm going to replace the exhaust manifold bolts. Either stud or bolts. What grade should they be?
Thanks,

 

I used stainless steel socket head cap screws for mine. I'd use grade 8 in regular steel hardware.


I thought the picture would be bigger. Its kinda hard to see the cap screws. I think you can make the pic bigger in my gallery.

 

I see the advantage of SS not rusting into the head or manifold. How are they holding up?

I guess SS is strong enough to handle the heat/cool cycles and the expansion/contraction involved?

 

Which stainless do you use? Some have a higher coefficient of expansion than steel. Ferritic is less. Cast iron is low.

Material Coefficient of linear expansion (10-6 in/in)



Cast Iron Gray 6.0
Steel 7.3
Steel Stainless Austenitic (304) 9.6
Steel Stainless Austenitic (310) 8.0
Steel Stainless Austenitic (316) 8.9
Steel Stainless Ferritic (410) 5.5