06-05-13, 09:21 AM
I've never come across a problem with stainless steel with aluminium.
Even if that did happen it probably wouldn't matter in this application: generally when taking the downpipes off you want the nut to come off the stud, not the stud to come out of the engine.
It is important to use differing grades of stainless if you're using it for both nuts and studs... if they're identical they can weld themselves as the nut is tightened. I use A4 for the studs and A2 for the nuts.
Even if that did happen it probably wouldn't matter in this application: generally when taking the downpipes off you want the nut to come off the stud, not the stud to come out of the engine.
It is important to use differing grades of stainless if you're using it for both nuts and studs... if they're identical they can weld themselves as the nut is tightened. I use A4 for the studs and A2 for the nuts.