CFR › Title 49 › Part 230 › §230.2649 CFR §230.26Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkWhen the tensile strength of steel or wrought-iron shell plates is not known, it shall be taken at 50,000 psi for steel and 45,000 psi for wrought iron.