Crossover pipe

[ivwshane]

I've decided to refurbish my exhaust system (I've already got good CAT). My crossover pipe is in good shape except for the studs. My plan was to replace the studs with stainless steel ones. I tried removing one of the studs using various methods, double nut, penetrating oil, heat, extractor. But I had no luck. Finally I decided to drill out the stud and re tap it.

For the life of me I cannot tap it, my tap just won't bite.

Can a machine shop remove and add new studs? If I messed up and drilled a hole too big, can they fix it?
Is there a better type of metal stud for this application?

What are my options?
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77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab

[busman78]

Had you got your tap to run a few threads it would of broke off, that metal has been heat cycled hard. A carbide tap might do the job for it will cut harder metal. Being able to anneal the metal would also be helpful.

To answer your two questions they are yes, as for Stainless that is a no, not a good choice for it is weaker than the steel 8.8 or 10.9 studs.

[SGKent]

heat the metal with a torch until the area is cherry red and then let it cool slowly. That should soften it.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[ivwshane]

When I heated it to try and remove the stud, I did not get it cherry red, did I need to?
_________________
77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab

[Wildthings]