4340 alloy steel bar 1.Grade:200,300,400 series 2.Size: 5mm* ... ,polished,brush etc4.Standard:GB,ASTM,JIS,AISI,DIN,EN,SUS etc.5.Stianless steel square bar is widely applied for petroleum ... , good surface . chemcial composition according to international standards of ASTM , AISI , JIS , ER , GB ,etc. contactWelcome your inquiries and hope we ...