First of all, we must distinguish the difference between ASTM A53 and ASTM A153. Most galvanizers are familiar with A153, Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware. However, we should be careful when we hear someone ask about the A53, which is a completely different specification. In fact, ASTM titles A53 as the Standard Specification for Steel, Black and Hot-Dip, Zinc-Coated, Welded and Seamless Pipe. Section 17 of ASTM A53, titled “Galvanized Pipe,” specifies the requirements for galvanized pipe ordered under this specification. The section requires that the pipe be hot-dip galvanized with a grade of zinc conforming to Specification B6, Standard Specification for Zinc, and gives weight requirements per unit area of the coating.
ASTM A53 does not contain the galvanized coating finish, appearance, or adhesion requirements that are present in ASTM A123, Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Product. Additionally, the coating weight per unit area required in ASTM A53 is exactly the same as the minimum coating thickness requirements for the same product in ASTM A123. Therefore, ASTM A123 is a more rigorous and comprehensive specification when it comes to galvanized coating. If a steel pipe is galvanized in accordance with ASTM A123, it will meet the requirements of Section 17 of ASTM A53.
In short, if a customer asks for a steel pipe to be galvanized in accordance with ASTM A53, you can say, "We galvanize in accordance with ASTM A123, which will meet the galvanizing requirements of ASTM A53."
