Zinc Chromate Plated Bolts

Yellow zinc plated 52.

Zinc chromate plated bolts.

Safer trivalent chromium coatings are becoming. It increases corrosion resistance and can be colored. They include nuts and bolts threaded rods structural bolts machine screws wedge anchors washers rivets and more in a variety of types and sizes including metric and inch. Therefore zinc serves as a protective barrier for screws.

For fasteners that need high corrosion or abrasion resistance a chromate conversion coating is applied over the zinc plating for additional resilience. Steel bolts vary under the test with some bolts lasting only three hours. Anoop if you use the torque equation t kdp as explained on our torque page the friction coefficient for zinc plated bolts is 0 22 vs 0 25 for galvanized. This is a secondary dipping process used on zinc or cadmium plated fasteners.

Fasteners are used for fastening and securing materials such as wood metal plastic or concrete. Well zinc can still corrode but it corrodes at a significantly slower rate than other metals and alloys. Whether a screw is galvanized or zinc plated it will feature a zinc shell. As with cadmium this material is toxic and its use is decreasing.

Clear zinc bolts have a lower corrosion resistance according to fastenal. This additional layer passivates the zinc and protects it from white rust. The clear zinc bolts are required to remain rust free during a salt spray test. When compared to steel for example zinc corrodes about 30 times more slowly.