2015 & 2016 HDG Specification Updates
What are the new changes to ASTM A123, A153, and A385?
The specifications for hot-dip galvanizing are required to be reviewed every 5 to 7 years by the standards organization, American Society of Testing and Materials (ASTM). In most cases, the changes to the specifications are minor and the specifications do not change much with each new release. In the latest review cycle, the ASTM committees have updated ASTM A123/A123M, A153/A153M, and A385/A385M accordingly:
A123/A123M-15: The latest revision to A123 reflects the need within the industry to define the responsibility for preparation of the hot-dip galvanized surface for painting or powder coating. Sections 6.2 and 6.4 were revised to clarify that confirmation should be reached between the galvanizer and the painter as to the responsibility for preparation of the hot-dip galvanized surface for painting or powder coating. Additionally, it is noted painting and powder coating of hot-dip galvanized items (including cleaning, profiling, and outgassing) shall be in accordance with D6386 and D7803, respectively, and shall be the responsibility of the applicator.
Table 1 was also revised to provide consistent formatting and to clarify the steel thickness ranges for each material category by updating the boundary symbols. The table below reflects the changes as they appear in the revised specification.
A153/A153M-16: The latest revision of A153 includes a number of minor clarifications to the wording of the specification.
A385/A385M-15: A comment was added to the latest revision of A385 to warn specifiers that hot-dip galvanizing of aluminum-killed steels may result in a thin coating unable to meet the minimum thickness requirements specified within ASTM A123/A123M.
The 2015 AGA publication Selected Specifications for Hot-Dip Galvanizing (blue book) will not be updated again for another couple of years until our supply of the books is consumed; but, an insert with these latest changes will be provided with the current print editions. The latest revisions of the individual specifications are currently available either for free with ASTM membership, or for purchase from the ASTM website at astm.org. Meanwhile, the AGA staff will continue to provide updates regarding specification changes at ASTM. If you have any questions related to the ASTM specification updates, please contact Corrosion Engineer, Alana Hochstein.
| Table 1: Minimum Average Coating Thickness Grade by Material Category | ||||||
|---|---|---|---|---|---|---|
| All Specimens Tested Steel Thickness Range (Measured) in. [mm] | ||||||
| Material Category | <1/16 [<1.6] | ?1/16 to <1/8 [?1.6 to <3.2] | ?1/8 to 3/16 [?3.2 to < .8] | ?3/16 to <1/4 [?4.8 to <6.4] | ?1/4 to <5/8 [?6.4 to <16.0] | ?5/8 [?16.0] |
| Structural Shapes | 45 | 65 | 75 | 75 | 100 | 100 |
| Strip and Bar | 45 | 65 | 75 | 75 | 75 | 100 |
| Plate | 45 | 65 | 5 | 75 | 75 | 100 |
| Pire & Tubing | 45 | 45 | 75 | 75 | 75 | 75 |
| Wire | 35 | 50 | 60 | 65 | 80 | 80 |
| Reinforcing Bar | -- | -- | -- | -- | 100 | 100 |
© 2024 American Galvanizers Association. The material provided herein has been developed to provide accurate and authoritative information about after-fabrication hot-dip galvanized steel. This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. The information provided herein is not intended as a representation or warranty on the part of the AGA. Anyone making use of this information assumes all liability arising from such use.