we are professional manufacturer 1.material grade:AISI 201,Y201Cu,202 AISI 303, 304, 304L,310,310S,316,316L,317,321 AISI 410,420,430,430F,431,4162.standard: ASTM A 276,A 484,A564,A581,A582, EN10272,JIS4303,JIS G 4311,JIS G 43183. production procedure: raw elements(C,Fe,Ni,Mn,Cr,Cu etc.,)--smelted ingots by AOD finery--hot rolled into black surface--pickling into acid liquid--polished by ...