Zinc-Plated Steel—Zinc-plated steel and powder-coated steel hooks have a barrier against rust that’s more durable than a plastic coating.
Plastic-Coated Steel—Plastic-coated steel hooks won’t scratch surfaces. However, the coating can peel away with heavy use, exposing the steel to rust.
Stainless Steel—Stainless steel fittings are naturally corrosion resistant, so they hold up in wet or humid environments.