钢铁产品的牌号表示方法已制定了专项标准。但近几年来钢铁产品牌号变化较大,甚至有些新牌号与旧牌号相比是“改头换面”,致使人们对钢铁产品牌号的变化情况难以掌握;有些产品牌号不仅采用符号相同而且在牌号中所处的位置也相同,因此不易区别,容易混淆,给实际应用造成了混乱。例如: Steel products, brand representation has developed a special standard. However, the grades of steel products have changed greatly in recent years, and even some new grades are compared with the old ones so as to make people difficult to grasp the changes of the grades of the steel products. Some of the grades of the products not only adopt the same symbols but also they are in the grades The same location, it is not easy to distinguish, easy to confuse, causing confusion to the practical application. E.g: