... metallurgy etcFasteners bolt and nut1.Material:Low-carbon steel,high tensile mid-carbon steel,alloy steel(35#,45#, ... Standard:DIN,ANSI/ASME,BS,GB,JIS,non-standard(DIN933,DIN931,DIN934 etc or BS917 etc or ASME ... metallurgy etcFasteners bolt and nut1.Material:Low-carbon steel,high tensile mid-carbon steel,alloy steel(35#,45#, ... ):NO.2,Tariff-freeZone,Qingdao,Shandong,China. good quality hex bolts and nuts