The Coating Selection Map: Matching Surface Treatment to Environment
Surface treatment selection is environment matching, not preference. A map from mildest to harshest duty keeps specifications honest and budgets sane.
The map
- C1–C2 (indoor, dry/urban): trivalent blue or black zinc, 96–200 h NSS — consumer electronics, office equipment.
- C3 (industrial/semi-outdoor): sealed zinc or zinc-nickel, 240–480 h — machinery, automotive interior-adjacent, telecom indoor cabinets.
- C4 (coastal/road salt): zinc-nickel or zinc-flake, 480–720 h — automotive chassis, outdoor enclosures, rail.
- C5 (marine/offshore): zinc-flake high-build, duplex systems, or A4/6-moly stainless — coastal structures, marine equipment.
- Chemical/food/medical: passivated stainless or PEEK — where chemistry, not weather, is the enemy.
Beyond corrosion: friction and appearance
The same map must respect torque behavior (zinc-flake topcoats stabilize friction) and cosmetics (PVD and anodizing for visible joints). Topprecision applies the full finish spectrum in controlled partner lines, publishes environment-class data per finish, and reviews customer exposure profiles to pick the least expensive compliant option — not the most expensive habit.
