ASTM A123 states the minimum average coating thickness grade for any specimen shall be one coating grade below that required for the appropriate material category and thickness in Table 1.
One of the most common queries received by subcommittee A05.13 is from specifiers requesting clarity regarding the term “one coating grade below.” It is not clearly defined whether the specifier should consult Table 1 or Table 2 to determine the value of “one coating grade below.” Specifiers attempting to reference Table 1 will find instances where “one coating grade below” incorrectly results in the same value as the required average coating thickness for all specimens tested.
To avoid such confusion, additional verbiage is proposed in 4 paragraphs (3.2.10, 6.1, 6.1.1, and 6.1.2) to clarify the value for “one coating grade less “is obtained by consulting the order of thickness grade values listed in Table 2.
Date Initiated: 11-07-2023
Technical Contact: Alana Fossa
Item: 000
Ballot:
Status: