Zinc Chromate Plated Bolts

It increases corrosion resistance and can be colored.

Zinc chromate plated bolts.

Clear zinc bolts have a lower corrosion resistance according to fastenal. Yellow zinc plated 52. Therefore zinc serves as a protective barrier for screws. Standard clear chromate leave a bluish white hue.

Yellow plated bolts have to last 600 percent longer before red rust can appear during the same test. When compared to steel for example zinc corrodes about 30 times more slowly. Whether a screw is galvanized or zinc plated it will feature a zinc shell. The clear zinc bolts are required to remain rust free during a salt spray test.

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. If you plug in this value to the equation you will get torque values for zinc fasteners that are roughly 12 lower than galvanized fasteners to achieve the same tension. Well zinc can still corrode but it corrodes at a significantly slower rate than other metals and alloys.

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. 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. For fasteners that need high corrosion or abrasion resistance a chromate conversion coating is applied over the zinc plating for additional resilience. As with cadmium this material is toxic and its use is decreasing.