GB/T4237 Standard specifies the Stainless steel hot rolled steel sheet and strip classification, code, order content, dimension, shape, weight and allowable deviation, technical requirements, test etc.GB/T4237 Standard Martensite stainless steel main steel grade:68Cr17(7Cr17),17Cr16Ni2,30Cr13(3Cr13),12Cr13(1Cr13) and so on.