Back to Mr VonSwirl's problem, :)
Does your stud look a bit like this, but stuck in the head.
https://www.aulro.com/afvb/images/im...13/02/1177.jpg
I used a cold chisel on the edge of the base 'flange' to unwind the broken stud. :)
It helped that I had previously cleaned the thread (stud and hole) and had applied anti seize before screwing it in. :D
As the NEW studs also stretched (and 1 broke) before reaching their stated torque, next time (if there is one) I'll just use normal M8 studs and torque carefully.
Not impressed with this stud type.:(
Deano :)
