Carbon tool steel
① The steel number is "T" to avoid mixing with other steel.
② The number in the steel number indicates the carbon content, which is represented by a few thousandths of the uniform carbon content. For example, "T8" means that the uniform carbon content is 0.8%.
③ The high manganese content is labeled "MN" at the end of the steel number, such as "T8MN".
④ The phosphorus and sulfur content of high -grade high -quality carbon tool steel is lower than the general high -quality carbon tool steel. The letter "A" at the end of the steel number is added to show the difference, such as "T8MNA".
Carbon structural steel
① It is composed of Q+digital+quality level symbol+deoxylonic symbol symbol. Its steel is crowned with "Q", which represents the yield point of the steel. The following numbers indicate the value of the yield point. The unit is MPA, such as Q235 to indicate the carbon structural steel with 235 MPA.
② Symbols that indicate quality levels and deoxygers can be marked behind the steel number. The quality level symbols are A, B, C, and D, respectively. The deoxidation method symbol F means boiling steel, B represents semi -definition steel, Z represents a tone steel, TZ indicates special taboo steel, calming steel does not marked the symbol, that is, ZT and TZ can not be marked. For example, Q235-AF represents A-class boiling steel.
③ Carbon steel with special use, such as bridge steel, ship steel, etc., basically use carbon -structural steel representation methods, but add the letter of use in the end of the steel number.
High -quality carbon structure steel
① The two -digit number at the beginning of the steel number represents the carbon content of the steel, which is expressed in a few percent of the uniform carbon content. No. 45 steel.
② High -quality carbon structure steel with high manganese content should be marked with manganese elements, such as 50mn.
③ Boiling steel, semi -calf steel, and high -quality carbon structure steel with special use should be specially marked at the end of the steel number. For example, a semi -definition steel with a uniform carbon content of 0.1%, and its steel number is 10B.
