... to weight ratio, greater corrosion resistance, longer military/medical /industry use ASTM B348-09 Gr2 barsSpecifications1. Material:Gr1,Gr2,Gr3,Gr4 ... BarStandardASTM B348, ASTM F67,ASTM F136, AMS 4928,ASME, DIN,JIS etcMaterialGr1,Gr2,Gr3,Gr4,Gr5,Gr7,G9,Gr12,Gr23Diameter 3 ...