If you plan on keeping it or want to be kind to the next owner, use a stud. If you don’t care, use a bolt.
Just throwing this in for information, https://www.fabory.com/en/knowledge...teel/the_seizing_of_stainless_steel_fasteners Andy
As the others said - there’s a reason they use the, steel stud, copper nut combination. Stick with it and use plenty of anti seize on the studs when you fit them.
I've had stainless for 8 years, still as good as the day they were put on. I know it's the rear but the front is just the same. Steve
I couldn't get that link to work at all Andy. Even just asking for fabory.com returns a 502 bad gateway message Hmmm Google finds the site, must be their server that's playing up, i'll try later. Thanks.
For anyone else who may be interested. Yes, I know this is in reference to cylinder head studs/bolts but I'm guessing the same logic applies. Torque Efficiency During engine assembly or maintenance, a bolt must be installed by torqueing it into place. Due to the head bolt’s design, it has to be rotated into its slot in order to engage the threads and secure it into place. This process creates both twisting force and a vertical clamping force, which means that when the cylinders within the engine’s combustion chamber begin accumulating load, the bolt will both stretch and twist. Because the bolt has to react to two different forces simultaneously, its capacity to secure the head is slightly reduced and it forms a less reliable seal in high-powered engines. By contrast, a head stud can be tightened into place without any direct clamping force applied through the tightening. A stud can be threaded into a slot up to “finger tightness,” or the degree to which it would be tightened by hand. Afterward, the cylinder head is installed and a nut is torqued into place against the stud. The nut torque provides the clamping force, rather than the torque of the fastener itself, and the rotational force is avoided entirely. Because the stud is torqued from a relaxed state, the pressure from the nut will make it stretch only along the vertical axis without a concurrent twisting load. The result is a more evenly distributed and accurate torque load compared to that of the head bolt. This ultimately translates into higher reliability and a lower chance of head gasket failure.
Hmmm, I just tried it on a different device and it works for me. Not sure what is required to make it work for you. Andy
That’s one to think about thanks Paul. I’m not sure that there isn’t some transfer of torque from the nut to the stud when torquing it up? It would be influenced by relative friction between nut and stud, compared with nut and head.
Brass exhaust nuts, now you'd showing your age Derek, they were always brass when I was an apprentice - many moons ago.
Showing my age? Is it that long since I last saw brass manifold nuts? Probably! Yes, they were always brass because they don't seize onto the stud. I notice that Ducati use copper plated ones now. Not really the same though.
However, I wouldn't use stainless steel studs in the heads....to start off with it is better to use molybdenum grease on stainless when in cast aluminium but it will melt and burn hard. I don't use copper grease on stainless bolts when in cast aluminium because it can cause a chemical reaction and threads can get damaged.....I use moly grease instead. IMO, steel studs in the heads for the exhaust flanges are best and copper grease is the correct thing to use.
I use Never-seez or Wurth brake paste. They are also helpful when used on spark plug threads in ally heads.
To summarise then, if I may, the new studs should be regular steel, not s/steel and the nuts should be brass and the stud should have some copper grease applied before going into the head and before putting on the nut. Thanks to all
Now that your fully trained at removing rusty studs I’ll drop you down the diavel to remove the standard exhaust
Sure thing Tom, please do. If only we could. I’ve now got to put the Monster back together again and then turn my attention to the ST2 I picked up cheaply back in Jan. I suspect that might be a little bit trickier
