Surface Finishing & Plating

The finish list

Plain, zinc plated, colour zinc, blue zinc, white zinc, black zinc, black phosphate, grey phosphate, black oxide, dacrotized, Ruspert, Xylan, nickel, bronze and spray paint. Coating thickness is specified with the coating — on the black bugle head line, for example, the plating can be laid down at 15 microns so that it carries the anti-corrosion duty rather than only colouring the screw.

What salt spray hours do and do not tell you

Across the catalogue, salt spray test time runs from 24 to 2000 hours depending on material and finish, and reaches up to 3000 hours on the stainless self drilling line. That is a comparative laboratory figure, not a service life. Use it to rank one finish against another, and tell us the real exposure so the ranking is applied to the right question.

Three blacks that are not the same thing

Black oxide is a conversion coating with an oil film and is largely cosmetic. Black phosphate holds oil and paint and adds modest protection. Black zinc is a zinc coat under a black passivate and is the one with real corrosion life. They look identical in a photograph and behave nothing alike on a building.