① 钢号开头的两位数字表示钢的碳含量，以平均碳含量的万分之几表示，如40Cr、25Cr2MoVA合金管
25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA
②钢中主要合金元素，除个别微合金元素外，一般以百分之几表示。当平均合金含量<1.5%时，钢号中一般只标出元素符号，而不标明含量，但在特殊情况下易致混淆者，在元素符号后亦可标以数字"1"，例如钢号"12CrMoV"和"12Cr1MoV"，前者铬含量为0.4-0.6%，后者为0.9-1.2%，其余成分全部相同。当合金元素平均含量≥1.5%、≥2.5%、≥3.5%……时，在元素符号后面应标明含量，可相应表示为2、3、4……等。例如18Cr2Ni4WA。
25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA
③钢中的钒V、钛Ti、铝AL、硼B、稀土RE等合金元素，均属微合金元素，虽然含量很低，仍应在钢号中标出。例如20MnVB钢中。钒为0.07-0.12%，硼为0.001-0.005%。
25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA
④高XX质钢应在钢号X后加"A"，以区别于一般X质钢。
⑤专门用途的合金结构钢，钢号冠以（或后缀）代表该钢种用途的符号。例如铆螺X的30CrMnSi钢，钢号表示为ML30CrMnSi。
合金管与无缝管两者既有关系又有区别，不能混为一谈。
25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA 25Cr2MoVAX质合金结构钢25Cr2MoVA 25Cr2MoVA
合金管是钢管按照生产用料（也就是材质）来定义的，顾名思义就是合金做的管子；而无缝管是钢管按照生产工艺（有缝无缝）来定义的，区别于无缝管的就是有缝管，包括直缝焊管和螺旋管。
