Specifying Galvanized Steel
Specifying hot-dip galvanizing is simply done by using ASTM specifications that ensure a top quality galvanized coating. This section will review the most important specifications relating to hot-dip galvanizing. When specifying hot-dip galvanizing as the means of steel corrosion protection, these specifications have been developed in order to produce a high quality coating. The most common specifications come from ASTM International. The following specifications pertain to hot-dip galvanizing:
- ASTM A123 – general
- ASTM A153 – small parts
- ASTM A767 – reinforcing steel (rebar)
- ASTM A143 – safeguarding against embrittlement
- ASTM A384 – minimizing warpage & distortion
- ASTM A385 – practice for high-quality coatings
- ASTM A780 – repair of galvanized products
- ASTM D6386 – surface preparation for painting over
The first three specifications listed here: ASTM A123, A153, and A767 will be reviewed in more detail on the following page.
Inspecting Galvanized Steel
As was discussed in the process section, inspecting galvanized steel is a fairly simple process. Zinc will not adhere to unclean steel, therefore a visual inspection of the product will provide a good assessment of the quality of the coating. There are additional tests for coating thickness and adherence that can be performed, and will be overviewed in the following pages.