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Unistrut Finish - Hot-Dipped Galvanized (HG)
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Hot-Dipped Galvanized (HG): ASTM A123 OR A153

In hot dip galvanizing, the finished part is immersed in a bath of molten zinc. This method results in complete zinc coverage and a thicker coating than pregalvanized or plated zinc. The zinc coating is typically 2.6 MIL or 1.5 oz./sq. ft. of surface area. This is the coating of choice for applications where severe corrosion is a design factor.

Unistrut products are available in three types of zinc coatings:
  • Electroplated (EG)

  • Perma-Gold (ZD)

  • Pregalvanized (PG)

  • Hot Dip Galvanized (HG)

Zinc coatings offer two types of protection:

  • Barrier: The zinc coating protects the steel substrate from direct contact with the environment.

  • Sacrificial: The zinc coating will protect scratches, cut edges, etc. through an anodic sacrificial process.

The service life of zinc coating is directly related to the zinc coating thicknessas shown below.

Comparison of Zinc Galvanized Finishes

  • Hot Dip Galvanized - 2.6 MIL

  • Pregalvanized - 0.75 MIL

  • Electro-Galvanized (SC1) - 0.2 MIL

  • Electro-Galvanized (SC3) - 0.5 MIL

  • Perma-Gold (SC1) - 0.5 MIL

  • Perma-Gold (SC3) - 0.5 MIL

As shown in the graph, when the zinc coating is double, the service life is double under most conditions.