Zinc Plating ASTM-B-633
Zinc plating is one of the more versatile finishes. It can be used for corrosion resistance, aesthetics or as a paint base over the zinc. Zinc plating can be chromated different colors after plating to achieve different results for a product. Clear or "bluebright" is often used as an inexpensive imitation for chrome plating. Yellow can be used as is or as a paint base. Black chromate gives a very smooth shiny black finish for decorative purposes or as an excellent corrosion resistant finish. Olive Drab is usually used for military applications to match camouflage. Zinc plating can also be dyed after plating for lot identification. Currently Seminole Metal Finishing does electrical ground green dye. As a general rule of thumb, the darker the chromate, the more corrosion resistant the finish with the same amount of plated thickness.
SPECIFICATION The specification that is generally associated with zinc plating is ASTM-B-633. This spec covers the general requirements that are needed to plate the customers' parts. A type or color and service class or thickness will be added to the specification on the customers purchase order to instruct the plater exactly what needs to be done to the part being plated. The spec also covers the baking requirements to relieve hydrogen embrittlement that are needed if a part is hardened or grade 5 or 8 steel. There are many internal specifications for large companies and Seminole Metal Finishing has many of them on file.
APPLICATIONS Zinc Plating, because of its low cost and versatility has many applications in industry. It has so many that it would be impossible to list them all. The bottom line with zinc plating is that if you a looking for an inexpensive corrosion resistant finish and that can be used for your product, then zinc may be for you.