Thicker coatings do provide better corrosion protection, but there’s a threshold where increasing thickness doesn’t significantly improve performance. The ideal coating thickness is between 5-10 microns. Anything thicker can affect thread engagement and torque during installation. While zinc coatings help with saltwater exposure, their protection diminishes over time. For enhanced durability, consider PVD coatings. It’s always best to use fasteners tested in the specific environment where they’ll be used for long-term performance.