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Supporting Specifications

Though all of the main galvanizing standards (A123, A153, and A767) reference these supporting specifications, when you are designing a project to be hot-dip galvanized, it’s important to be aware of these as well.  There are a number of specifications the designer/fabricator/specifier should consider before galvanizing, as they give best practices on steel selection and how to design for the hot-dip galvanizing process.  Additionally, there are a few specifications specifiers should be familiar with for post-galvanizing treatments. 

Pre-Galvanizing Supporting Specifications

pre-galvanizing support specifications
pre-galvanizing support specifications

ASTM A143: Practice for Safeguarding Against Embrittlement of Hot-Dip Galvanized Structural Steel Products and Procedure for Detecting Embrittlement

Embrittlement is the loss or partial loss of ductility in a steel where an embrittled product characteristically fails by fracture without appreciable deformation.  Types of embrittlement commonly encountered with galvanized steel are related to aging phenomena; cold working and absorption of hydrogen. The design of the product and selection of proper steel for its suitability to withstand normal galvanizing operations is the responsibility of the designer and fabricator.  

ASTM A384: Practice for Safeguarding Against Warpage and Distortion During Hot-Dip Galvanizing of Steel Assemblies 

This specification will detail the best design practices to avoid warpage/distortion of products during hot-dip galvanizing due to the temperature the material is heated to during the process. 

ASTM A385: Practice for Providing High-Quality Zinc Coatings (Hot-Dip)

 This specification has details on steel selection and other design practices such as venting/draining, welding, etc. to ensure the best quality product after galvanizing.

ASTM A1068: Standard Practice for Life-Cycle Cost Analysis of Corrosion Protection Systems on Iron and Steel Products

 This specification is not JUST for HDG, but rather is an evaluation tool for specifiers to compare total costs of any steel corrosion protection method.  The online calculator at galvanizeit.org/galvanizingcost/ uses this accepted equation as well. 

Post-Galvanizing Supporting Specifications

Inspection of galvanized steel
post-galvanizing support specifications

ASTM A780: Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized Coatings

 This specification details the accepted forms of touch-up and repair for galvanizing whether done at the galvanizer’s facility or by the designer/contractor in the field during erection.

ASTM D6386: Practice for Preparation of Zinc (Hot-Dip Galvanized) Coated Iron and Steel Product and Hardware Surfaces for Painting

This specification details how to prepare hot-dip galvanized surfaces (newly galvanized, partially weathered, fully weathered) for paint to create a duplex system.

ASTM D7803: Practice for Preparation of Zinc (Hot-Dip Galvanized) Coated Iron and Steel Product and Hardware Surfaces for Powder Coating

 This specification details how to prepare the galvanized surface (newly galvanized, partially weathered) for the creation of a duplex system using powder coating.