ASTM Standard A500
ASTM Standard Specification for cold-formed welded and seamless carbon steel structural tubing in rounds and shapes.
A500 covers cold-formed steel round, square, rectangular, or special shape structural tubing for welded, riveted, or bolted construction of bridges, tanks and buildings, and for general structural purposes. Common Grades stocked and produced are Grades B and C and can be subjected to most of the usual fabricating operations.