Are black phosphate screws rust resistant?
Correspondingly, will black phosphate rust?
A. David - Yes, black oxide can be used as a rust retardant, but it is not as effective as black phosphate. The black zinc phosphate acts sacrificially to protect the steel, whereas the black oxide will rely on the after-finish for corrosion protection.
Consequently, what type of screws are rust proof?
4 Answers. The stainless steel screw will absolutely be the best screw to resist rust. Stainless steel screws are rust-resistant throughout the entire screw, not just on the surface. The other screws are only covered with a rust-resistant coating on their surface, which will break down or wear off over time.
Galvanised screws and nails are zinc coated nails that have undergone a galvanisation process. This process means the nails have a protective barrier which makes them resistant to rust and corrosion. The zinc coating on nails treated in this way acts as a sacrificial anode, and will decay before the metal inside.