ASTM A333 is a specification given by the American Society for Testing and Materials (ASTM) for Seamless and Welded Steel Pipe for Low-Temperature Service. This type of carbon steel pipe is typically used in low-temperature applications, as the steel is treated to control its microstructure and improve its resistance to low-temperature impact toughness.
The A333 carbon steel pipe comes in several grades, with the most common being Grade 1 and Grade 6. Each grade has different chemical and mechanical properties and can handle different low-temperature applications. The “A333” simply refers to the ASTM specification the pipe meets. This standard covers wall seamless and welded carbon and alloy steel pipe intended for use at low temperatures.