Identification method

There is a manufacturer's factory mark on the steel. In addition to the model, there is also a brand, which is usually represented by a letter. The other is that when you buy each piece of steel, there is an iron plate with a factory batch number on it. You should ask the merchant to sell the goods. The batch number on the warranty certificate given should be the same as the batch number on the iron plate. of.

Supplement: Shagang’s mark is SG