Galvanized steel is a commonplace item in any hardware store from poles to fittings to bolts. The metal materials are used to hold together fence boards and are used in many guard rails on the side of the road. But how do they galvanize the steel? Here’s everything you wanted to know about the galvanization process.
Entering the Kettle
Fabricated steel is immersed into a molten zinc bath at a steamy 840 to 850 degrees Fahrenheit. The 150-year-old practice uses galvanizing tanks for the hot-dip galvanization process. The zinc bonds to the steel creating a protective layer. The steel comes out of the kettle with a bright appearance. The galvanizer is an experienced chemist and metallurgical worker creating corrosion protection for the versatile metal.
Grades of Zinc
Galvanized steel comes in five grades of zinc. Containing a minimum of 99.995% zinc is the London Metal Exchange Grade. A minimum of 99.990% makes Special High Grade a high purity zinc galvanization. High grade starts at 99.95% followed by Intermediate Grade at 99.5%. Prime Western Grade contains 98.5% zinc with the addition of 0.5 to 1.4% lead.
General Concerns On-Site
The steel can be rejected on-site for a variety of reasons. Common ones include bare spots, dross protrusions, runs and lumpiness, general roughness, mottled or matte gray coating, ash inclusions, rust stains and flux inclusions. Some issues may self heal, but many are grounds for exclusion. The galvanizer can offer better reasons for why certain pieces are rejected.
Now that you know a little more about how the steel is galvanized you may have a little more appreciation for the silver hardware and pipes. They withstand the elements to make sure your home and businesses benefit from the long-lasting materials. Galvanized steel is relatively easy to maintain with decades of corrosion protection even out in the elements.