How best to remove exhaust studs ?

[McCabe-Thiele (Ted)]

When I removed the front pipes on my 500 three of the studs came out with the nuts.- so in an ideal world I would like to replace them with new SS studs.
On examining the remaining five studs I suspect they are not original as they are fully threaded with no unthreaded section.
I have tentatively tried  using the two nuts method to remove one but it has not worked as the nuts just moved up the threads despite being very tight. I am wary of stripping the threads to compound the issue.

Is there a better method of removing them as I do not fancy breaking/or stripping a stud by being cack-handed.

I have a plumbers gas blow torch as a heat source if this might help?

[Oddjob]

Try using flanged serrated nuts Ted, flange to flange. Must be serrated though as the serrations grip like hell to each other, bit of heat before attempting to remove the stud. Oh and I normally thread a ring spanner onto the stud first so I can get a good grip on the inner nut.

[Trigger]

I have removed hundreds if not thousands of exhaust studs and never snapped one.
You will require a lot of heat until it is nearly glowing red. Someone may of used threadlock or a retainer on the threads, this needs to be broken down. And if you have all thread try getting the nuts as close to the head as possible so, there is no twist in the stud. 

[deltarider]

I haven't been lucky with them. I had to replace most of them. A mechanic helped me, because some holes needed a timesert, a method he prefers over helicoil. On his advice I used but OEM studs and not ss. When either loosening or fitting the exhaust system, be very, very careful with tightening (or loosening) everything. I wish I could give you the right working order; opinions seem to vary. Do not use a torque wrench on those 8 6mm nuts. It will work well only once and thereafter you may encounter problems.
Later models had ubs nuts which do not need spring washers. I haven't tried them yet. They may be better for the job, but they offer a little less grip for your spanner ofcourse.

[Matt_Harrington]

Ted, I've used ones like this before but they do damage the threads but do the job:
https://www.tengtools.com/products/service-tools/extractors/1-2-stud-extractor-socket-10mm

If you need to remove a stud that has an unthreaded portion and you want to reuse the stud, this style work well:
https://www.amazon.co.uk/Lisle-71200-Stud-Remover/dp/B0041ESF2G
My version of this tool is at least 50 years old....

[McCabe-Thiele (Ted)]

Thanks for the links  Matt - I have a set of stud extractors but they do not go down to M6 - the type with three offset roller balls.

My preferred route would be heat & an extractor that I could use whilst the stud is still hot.

[K2-K6]

I've got the same TYPE as Matt's second link there.

It's very old and not same make but very effective if you've clearance around the stud for access.  It grabs right down at the face of casting to get as close as possible to inserted section of studs.

Pretty effective if it fits.

[McCabe-Thiele (Ted)]

I had a set of three that were RR tools from the 1950s that worked great but as a teenager I abused them until they broke - the 3/8 one would have been perfect. They were like a small T handle design.