Since I live in part of the country that doesn't feel the need to throw food seasoning onto the roads when it gets cold, my 14 year old MINI does not have any rusty parts. Or, so I thought. I found a slight issue with rust in the bolts that secure the side mirrors to the doors. Certainly it's a very minor thing, but it bugged me. And it was only going to get worse over time. At some point, if left alone, it could prevent removal of the door mirrors should I ever need to take them off. So, for about $4 I replaced all six bolts with nice stainless steel ones. I wasn't able to find the correct sized socket cap bolts at my local full-service hardware store, but the Interwebs came to the rescue and offered at least two great solutions for stainless fasteners in that size: McMaster-Carr and Bolt Depot.
Did that about three years ago. I think I might even have a bag or two of "full sets" lying around somewhere if anyone wants. I'd have to go digging though.
I've used McMaster-Carr for years, they have everything! I haven't tried bolt depot, have to look into them as I need to restock some of my hardware reserves..... The cool thing about McM-C is since they're in Chicago if you order it by 4 pm, you have it the next morning!
If you ever get around to finding those savvy let me know! New Hampshire hasn't done me any favors with rust issues
Well.... Here is the thing about stainless steel... It will rust.... under certain conditions... If SS is threaded into a ferrous fastener (not Ferris Bueller, which could be painful), the iron in the threadsert will initiate rust on the threads on your nice SS bolt.... I suggest coating those sparkly SS threads with antiseize... This is what I use in the shop... If not, you will be wondering why those nics SS bolts you replaced are frozen in the mirror housing and they won't come out... Permatex Nickle Anti-Seize Lubricant View attachment 77124.pdf
I've never had that happen, but I've had a few stainless in stainless lock up - once they do you're never getting them apart again!
We use a lot of stainless to stainless fasteners on projects in our shop. Once you get galling occurring on the threads, the fastener pretty much locks up immediately. At that point you can forget it and start over with new fasteners.... What we do is always apply some anti seize on the threads and never have an issue.
Metal man hit the bolt on the head. If you use a stainless bolt screwed into mild steel all you are really accomplishing is preserving a pretty bolt head. Anti-Seize will help a lot. I was surprised when I learned this way back in my early USAF days when I went to a week long corrosion control school. Galvanic Corrosion: All metals have specific relative electrical potential. When metals of different electrical potential are in contact in the presence of moisture, a low energy electric current flows from the metal having the higher position in the galvanic series. This is called "galvanic action." Galvanic corrosion is a form of electrochemical corrosion that occurs when two dissimilar metals come together in the presence of an electrolyte to form an electrical couple, known as a galvanic couple. The more noble or cationic the metal, the less likely it will corrode relative to the other metal it is in contact with. It should be noted that mill scale is cathodic to steel and an electrical current can easily be produced between mill scale and the steel. Weld metal may also be anodic to the base metal, creating a corrosion cell when immersed. Additionally, a depletion of oxygen in crevices of a metal can cause the area to become anodic to the metal outside the crevice which is exposed to oxygen.