Gauging plates, offered in both aluminum and carbon steel, are used in conjunction with steel pigs to prove pipe roundness and to ensure excessive weld penetration or debris does not exist in the line, as well as, proving minimum bend radius prior to intelligent pig runs. Gauging plate o.d.'s range anywhere from 90% to 95% of the internal diameter of the pipe and can also have slots cut into the circumferential perimeter for easier deformation identification. Depending on the size of the pig, the thickness of the gauging plate can be 1/8", 1/4", 3/8" and 1/2" thick. The standard construction material for gauging plates is aluminum, but steel can also be used.