So I was installing an axle back exhaust and stripped all 4 bolts because of how rusty they were. So I took the grinder to them and cut them off, now I can’t bang out the old ones. Are they studs or bolts? For reference I have a 2012 Infiniti g37x coupe

 

Since you already grinded the rears off and can’t take it out might as well just drill it honestly, if their is no other option.

 

a bolt has a hex head and a stud does not. does that answer your question since we can't tell if the fasteners were original factory or some aftermarket installed fasteners.

 

Yup gonna have to grind more and drill it out if they are studs. If you had the exhaust off the car in a vise you could probably bang them out