Zinc Plating

Zinc plating is a corrosion-resistant finish applied to screws and other steel fasteners. A thin layer of zinc is deposited onto the screw surface, most commonly by electroplating, although other methods like mechanical plating and zinc flake coatings are also used. Zinc protects steel in two ways: it acts as a barrier to moisture and oxygen, and it provides sacrificial protection, meaning the zinc will corrode before the underlying steel does if the coating is damaged. Zinc plated screws are often identified by their appearance, such as clear or blue zinc, yellow zinc (from chromate conversion coatings), or black zinc finishes.

Zinc plated screws are popular for general-purpose indoor and light outdoor use because they offer good rust protection at a reasonable cost and maintain consistent thread fit due to the thin coating. The tradeoffs are that zinc plating is not as durable as heavier-duty corrosion systems in harsh environments like coastal, marine, or constant wet exposure, where stainless steel or specialized coatings are often a better choice. For certain high-strength fasteners, electroplating can introduce hydrogen embrittlement risk, so proper process controls and post-plating baking may be required depending on the fastener grade and specification.