How is the size of round steel or cast-iron determined?

The size of round steel or cast-iron is typically determined by its diameter, which is measured in inches or millimeters. This measurement can be taken directly from the finished product or specified according to industry standards. Additionally, the size may be defined by the dimensions of the application it is intended for, influencing factors like load-bearing capacity and structural requirements. Manufacturers often follow specific guidelines and standards, such as ASTM or ISO, to ensure consistency and compatibility in sizing.