HDG Coating Specifications

There are a number of specifications that have been developed over the years for hot-dip galvanizing in order to produce a high-quality coating. The most common specifications used in North America are ASTM specifications. However, some design engineers and/or fabricators will call out international or other specifications published by independent organizations, such as AASHTO.

There are three main governing ASTM specifications for hot-dip galvanized steel:

  • ASTM A123/A123 M: Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products
  • ASTM A153/A154 M: Standard Specification for Zinc Coating (Hot-Dip) on Iron and Hardware
  • ASTM A767/A767 M: Standard Specification for Zinc-Coated (Galvanized) Steel Bars for Concrete Reinforcement

Additionally, there are a number of important supporting specifications all design engineers, fabricators, and steel detailers should familiarize themselves with, as they pertain to design best practices, steel selection, and other important topics. The following pages will provide more detail on all of these specifications.