Difference Between 500 Grade and 500D Grade Steel In Fe 500 and Fe 500D, "Fe" signifies iron, and "500" denotes a minimum yield stress of 500 N/mm². The "D" in Fe 500D stands for higher ductility. Both have similar tensile strength, but Fe 500D offers better yield strength and is ideal for large-scale projects like bridges. These bars also contain lower harmful sulphur and phosphorus levels. https://www.comaron.com/blog/Grade-fe500-fe500D »