Regulationcurrent
49 CFR 179.202-4
-4 Thickness of plates.
Current as of 2026-08-18 Government source
eCFR editorial compilationAuthoritative but unofficial
View source The wall thickness after the forming of the tank shell and heads must be, at a minimum, 9/16 of an inch AAR TC-128 Grade B, normalized steel, in accordance with § 179.200-7(b).
[80 FR 26749, May 8, 2015]