1.steel grade:20B,40B,45B,50B 2.standard:AISI,ASTM,BS, ... on We own the eight profession engineers of high strength steel wire,and five QC to keep the products good quality ... 10 years ,next we introduce the products as follows:1.Steel grade :20B,40B,45B,50B,45Cr,50Cr,55Cr.2.Standard ...