49 C.F.R. § 179.201-4 Material.
Title 49 - Transportation
All fittings, tubes, and castings and all projections and their closures, except for protective housing, must also meet the requirements specified in ASTM A 262 (IBR, see §171.7 of this subchapter), except that when preparing the specimen for testing the carburized surface may be finished by grinding or machining. [68 FR 75762, Dec. 31, 2003]
Title 49: Transportation
PART 179—SPECIFICATIONS FOR TANK CARS
Subpart D—Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW)
§ 179.201-4 Material.