Let’s say you’re building a metal gate with wood slats for side yard … or maybe just replacing the wooden slats ???
I have a lot of people come in and buy stainless carriage bolts and nuts in an effort to prevent rust stains on the wooden slats. Inevitably, one of them comes back a few months down the road unhappy and complaining that the bolts we sold them weren’t stainless. So, what’s with the rust stains…. @X1?~!
The explanation is simply this …. If the hole that was drilled through the metal gate frame is not coated with some type of Rustoleum or galvanized paint, you have raw metal here. Raw metal creates rust rather quickly, especially during rain storms and times of moisture. Water and/or dampness travels along the threads of the bolt and comes in contact with the raw steel from the hole drilled through the metal.
This is ground zero for the origination of your rust. It’s not the bolt. Seriously, you could throw our stainless carriage bolt in a pool and come back a year later, and it will look like new.