Exhaust system replacement

['89AccordLX(Rus)]

Hello,

I am planning on replacing my exhaust system with new stock components. All of the pipes from the manifold back, including the cat, I have already purchased. Now I need to buy the nuts and bolts required to bolt it together. I looked in the Honda EPC, and the manifold to downpipe nuts seem to be different from the downpipe to cat nuts. Both are 10mm self locking, but what makes them different? Also, can I simply go to an autoparts store (or hardware store) and purchase these, or are they exhaust-specific? Would I be better off getting the OEM hardware? Thanks for any input.

Edit: It seems as if everything but the cat bolts can be purchased pretty cheap from the dealer (cat bolts ~$7 each). Are those cat bolts specialized or are they commonly available at stores?

[danronian]

They should be the same as any part you get in the store, they may just be a strange thread size or something. I know the ones on my car are rusted completely so I really doubt they are stainless or anything other than plain steel.

[Strugglebucket]

when i replaced my cat i used grade 10 metric bolts from a hardware store and new oem nuts.

[shepherd79]

I use galvanized bolts and nuts on my exhaust. this way it will never rust.

[POS carb]

they are not 10mm (unless that's the diameter of the bolt) they are 14's I think and they are only self locking b/c they get so hot and rusted lol

the 10's you are seeing are probably the 2 hanger nuts for the flex pipe to the engine block behind the oil pan