Couple of years ago I let a local workshop change my stock hood hinges to a set of stainless steel ones, complete with ss bolts. That workshop didn't copper grease those 4 bolts that head into the hood itself... Today I decided to install my Delta Light Bar and change the steel hinges back to stock at the same time. Knowing the steel hinges use 5mm hex bolts I decided to nip back to the same workshop to have him loosen them as my set of allen keys would probably not be suitable for the job. Well, the first 3 took a hell of a lot of pressure but they did loosen... the last one, however, wouldn't budge and then catastrophe hit... the workshop's tool breaks off inside the bolt. The only way to get that bolt out was about an hours worth of drilling and cutting resulting in one knackered steel hinge. All because they didn't apply a little copper grease when they put them on in the first place. Stainless bolts can seize and when they do they ruin a perfectly good afternoon.

 

You can coat the bolt with milk of magnesia also if you do not have copper anti seize. It works, we used for many years in industry.

 

You should see my jet ski. I sheared off a stainless bolt into the case (flywheel housing bolts). Then I snapped off an easy out inside the bolt. Then I snapped out a stronger easy out inside of the first easy out which was still inside the bolt.

So I just left it there and used some extra sealant where the bolt should have been....

 

Wow - that sucks. The upside is that this actually made me laugh aloud.

 

Stainless Steel does not mean stronger. Lots of people believe they are stronger than regular steel, this is not the case. They just don't rust out as fast.

But here's a tip. When you do have one that gets seized up, use regular ole BBQ lighter fluid to loosen it up. Apply and let soak for a few minutes.

 

The higher the grade of stainless, as in rust avoidance, means a weaker part. True stainless five knives, for example, won't hold an edge. It's just too soft. It has less carbon in the steel.

Anytime you have dissimilar metals, you run the risk of "galling". As you said, copper anti seize does the trick.

 

The problem with using stainless steel nuts and bolts together is thread galling.

Here is some interesting reading on the subject:
Stainless Steel Galling / Locking Up / Freezing Up

 

I'm so glad I saw this. Thanks for that info. How I know why they aren't used as often.

 

Yup. This was the first time I've had a problem but then I normally grease the ones I install myself. On my old CJ I used loads of ss bolts without problem.