54.05-6—Toughness test temperatures.
Each toughness test must be conducted at temperatures not warmer than −20 °F or 10 °F below the minimum service temperature, whichever is lower, except that for service at or below −320 °F, the tests may be conducted at the service temperature in accordance with § 54.25-10(a)(2).
[CGD 85-061, 54 FR 50964, Dec. 11, 1989]