What is A333 Gr 6 carbon steel pipe?The A333 Gr 6 Carbon steel pipe is a low temperature carbon steel pipe (LTCS) that is ASTM A333/A333M standard. The ASTM A333(ASME S/A-333) piping class allows for cryogenic service, and this specification almost entirely covers seamless nominal (average) wall thickness piping. The A333 pipe has nine different grades, denoted by the numbers 1, 3, 4, 6, 7, 8, 9, 10 and 11. The Gr 6 designation refers to the grade of steel that meets the requ...