So I measured an exhaust stud because I need to replace the nuts, the nuts that are already on there have shrunk from rust so they went from I think 14mm to 12-13mm. These thread through the bottom of a catalytic converter to connect the front pipe to the front catalytic converter and this is on a Nissan.
My problem is when I pulled a stud off and measured them like I would a metric fastener, I got weird results. Diameter came out to 3/8th of an inch and pitch came out to 1/16th of an inch. Based on my math that would be close to an M10x1.6mm. The only problem is I have never heard of 1.6mm thread pitch, usually it's stuff like 1.25, 1.5, 1.75 or 2mm.
So either I seriously messed up the measurement or there's something I don't know.
I had also considered that maybe these are just SAE fasteners. I tried looking for something like 3/8thx1/8th but it appears SAE has this other weird system for doing thread pitches (based on overall length?).
Maybe I should just remove all of the studs and replace the stud+nut setup with a bolt+nut setup, where the bolt has no threads on the shank and passes through the threads on the cat converter flange without using them at all. This would mean the bolt+nut provides the clamping force instead. Is that a bad idea?
My problem is when I pulled a stud off and measured them like I would a metric fastener, I got weird results. Diameter came out to 3/8th of an inch and pitch came out to 1/16th of an inch. Based on my math that would be close to an M10x1.6mm. The only problem is I have never heard of 1.6mm thread pitch, usually it's stuff like 1.25, 1.5, 1.75 or 2mm.
So either I seriously messed up the measurement or there's something I don't know.
I had also considered that maybe these are just SAE fasteners. I tried looking for something like 3/8thx1/8th but it appears SAE has this other weird system for doing thread pitches (based on overall length?).
Maybe I should just remove all of the studs and replace the stud+nut setup with a bolt+nut setup, where the bolt has no threads on the shank and passes through the threads on the cat converter flange without using them at all. This would mean the bolt+nut provides the clamping force instead. Is that a bad idea?