... )round steel bar 2)standards :GB,JIS,DIN,ASTM and so on 3)materials :15Mn,16Mn,50Mn,65Mn,etc . 4)diameter :4mm-400mm 1)round steel bar ... 2)standards :GB,JIS,DIN,ASTM and so on 3)materials :15Mn,16Mn ... ,etc .4)diameter :4mm-400mm5)best exporter TypeRound steel barStandardGB/ASTM/DIN/JIS and so onGrade15Mn,16Mn,50Mn,65Mn,etc .Diameter4mm-400mm ...