A: The item is zinc-plated, so not the same as galvanized. If the coating is rubbed off, then you are at risk for rusting. This could be caused from installation, or for your instance, wind blowing in the yard causing abrasion. Once the coating is gone, it will begin to oxidize and form rust. There are too many factors to know exactly how long it will last. If you want to not think about it anymore, buy stainless steel clamps. They are a little more expensive, but still cheap in the overall aspect of most projects. Especially, if you take in consideration their lifetime. Good Luck.