When a customer asks for “1,000‑hour salt‑spray resistance,” many suppliers simply nod. But as a screw manufacturer, we know the difference between marketing claims and real lab results – especially between mechanical galvanizing and Ruspert.

Mechanical galvanizing is a cold‑impact process: zinc powder is mechanically peened onto the screw surface. It’s cost‑effective and gives a uniform appearance. But here’s the reality – a standalone mechanical galvanized layer typically fails salt‑spray testing (ASTM B117) within 24 to 72 hours. It has micro‑porosities, and while it protects against moderate indoor humidity, it quickly shows white rust – and then red rust – in harsh outdoor or coastal environments.

Ruspert, on the other hand, is a multi‑layer composite coating. It combines a base zinc layer, a conversion film, and a ceramic‑like topcoat. With just 5–15 μm total thickness, it consistently passes 1,000 hours with only minor red rust spots, and often exceeds 1,200 hours. That’s because the top seal layer blocks chloride penetration – something mechanical plating alone cannot do.

But salt spray isn’t everything. For high‑strength screws (grade 8.8 and above), hydrogen embrittlement is a silent killer. Mechanical galvanizing involves acidic pickling and can introduce hydrogen – a risk for delayed fracture. Ruspert uses an alkali‑based, acid‑free process, eliminating that danger entirely. Plus, Ruspert is chromate‑free and RoHS‑compliant, with optional colours for easy grade identification.

So which one do we recommend for your steel‑deck or timber screws? If you need 1000 hours, pure mechanical galvanizing won’t get you there. The reliable solution is mechanical galvanizing + Ruspert topcoat – or a full Ruspert system from the start. We offer both, with batch‑test certificates for every 1,000‑hour run.

Because when your screws face rain, salt, and time – we don’t guess. We prove it.