Q235A, Q235B, Q235C, Q235D. This is a class distinction represents the main difference is the temperature of the impact of it! A, B, C, D, are different, referring to the impact of their performance in different temperatures. Were: Q235A level, is not to shock; Q235B grade, is 20 degrees room temperature impact; Q235C level, is 0 degree impact; Q235D level is -20 degrees impact. The impact of different temperatures, the impact of values ​​are different. Elements: A, B, C, D followed by decreasing sulfur content; A and B, the same phosphorus content, C content followed by phosphorus, D phosphorus content of at least.