Are stainless steel bolts good for muffler systems?

[carcrossy]

I bolted one side of my catalytic converter with stainless steel bolt/nut and the nut and bolt seemed to be welded together after only a few weeks. Bolt broke finally after much torquing to get it off.

[steve_o1989]

I have found that when using stainless you have to tighten them very slowly or they will seize up for some reason. We use them for the piping in the tanks we build. If you just give 'er beans and tighten it like you would a regular bolt its going to sieze.

[jr_ss]

Never sieze is a great tool. I use SS hardware everyday in my job. I have SS hardware on my exhaust and have never had a problem. What probably happened is some how, some way, the bolt/nut gauled and when you tried to pull it off, it wasn't happening. It's common for the 1/4" or 5/16" bolts to do that...

[FrankDukes]

Originally Posted by jr_ss

Never sieze is a great tool. I use SS hardware everyday in my job. I have SS hardware on my exhaust and have never had a problem. What probably happened is some how, some way, the bolt/nut gauled and when you tried to pull it off, it wasn't happening. It's common for the 1/4" or 5/16" bolts to do that...

Do you mean "Anti-Seize" which is a grey substance that comes in a tube and spread on threads to act as an Anti-Seizing agent?

[carcrossy]

I am not a Metalurgist, I am a tool and die maker and a mechanic. The best way I can explain "gauling" is that it is metal fusion. That is to say there is interference between the two metals, usually both soft, and they litterally melt at the threads, and metal is transferred. Similar to cross-threading. EVERY time I bolt something together, I make sure, with my fingers, that the nut will go full depth on the threads. If it doesn't I make it right. I bought am item , back a few years ago, and fine thread nuts were supplied with course thread screws. As I am sure this was not true in your case, I would blame the problem on poor quality metal. Many people have misconceptions about stainless steel. MILD stainless has less tensil strenght then mild steel! Put a stainless nut on top of a battery, and see what happens in a few days. With a NEW nut and BOLT, the nut should have a very small amount of wiggle. This is true with NYLEX untill you enter the plastic. --Just MY 2 cents again------

[sultan]

i used grade 8 zinc plated junk from home depot, lol.

needed longer bolts for my exhaust spacers (added an extra flange, shoulda bought 2) so i just grabbed the first thing that looked the right size, hahahaha

[jr_ss]

Originally Posted by FrankDukes

Do you mean "Anti-Seize" which is a grey substance that comes in a tube and spread on threads to act as an Anti-Seizing agent?

Never seize, anti-seize, it's all the same stuff... There are many names for it. But yes, it's the grey stuff you mention...