Purpose of Conical Washers

[money pit]

What is the purpose of the conical washers used on the exhaust manifold? Are they supposed to be on all bolts and studs? Can I use regular flat washers or lock washers? When I bought my engine it didn't have exhaust manifolds. I saw the washers in the service manuals. Thanks

 

[Rat Rod AL]

I don't know the answer ,but if it comes down to you needing some I know who has a bunch !

 

[Rapidfire]

I think they go on stock exhaust manifold small blocks?

 

[Daves69]

Looks like they distribute the clamp force further out from the stud or bolt? Maybe help deter manifold cracking and warpage?

 

[Chryco Psycho]

They also act as a lock washer , the cone will flatten slightly & help keep it tight as it expands & contracts with heat .

 

[70chall440]

All of the above, additionally due to the dissimilar metals (cast iron and steel), the conical crush washers can take the expansion and contract of heat cycles without loosening.

 

[moparleo]

They act like a spring to maintain tension on the fastener.

 

[money pit]

Thanks everyone for the great response and info.