Forget what you heard. Forget what you think. Forget what you know.
Sliders are made of very heavy duty high carbon steel and are supposed to take a tremendous amount of weight without breaking or bending.
No matter what type of coating they have, from rattle can, to a professionally applied powdercoat, if you live in harsh environments they will rust.
It is your responsibility to take a good care of them and re-spray them, if necessary.
Otherwise, because of trail damage, and road damage, they will look like ass. Like mine do.