Troy Isakson wrote:Stainless steel bolts will also need replacing someday. How do you know that the bolts you spent 100 hrs on last year would have been fine if they were stainless? There is no controlled study of any kind to refer to is there? I've placed many plated bolts and many stainless bolts in the same area. I guess we will see which ones look better in the future and I can answer my own question....
Stainless steel will outperform zinc plated carbon steel in any wet, humid or otherwise corrosive environment, and to a lesser extent even in dry environments. Yes, this has been studied by countless scientists, engineers, organizations and everyone else going else going back since stainless steel was invented, and the studies have confirmed in-practice findings in nearly every industry that exists worldwide where corrosion resistance matters.
Stainless bolts will also have to be replaced eventually, but with a far smaller frequency. Replacing carbon steel bolts once every 20 years is a lot worse than replacing stainless steel bolts once every 60 years. We might not know exactly how long stainless steel bolts will last in various environments in rock climbing, but that's only because they have done a fairly good job providing longevity. In many cases, even the oldest stainless steel bolts are still serviceable unless they were one of the few known crap designs. By contrast, virtually any carbon steel bolt more than 30 years old just about anywhere is probably in need of replacement at this point. If it was not stainless and it was placed before 1985, there is a solid chance it's not in the best shape at this point.
I know of countless carbon steel bolts that are only 10 years old that need dire replacement. I cant say the same about many stainless steel bolts of the same age.