This standard specifies the designation,ordering information,dimension,shape,mass and tolerance,technical requirements,test methods,inspection rules,packaging,marking and certificate of non-quenched and tempered hot-rolled steel wire rods for cold heading. This standard is applicable to non-quenched and tempered steel hot-rolled wire rods,with nominal diameter ofΦ5 mm～20 mm,for manufacturing fasteners such as bolts,screws and studs,etc.,and cold heading steel wire.Dimensions exceeding this standard shall be agreed between manufacturer and purchasers according to this standard.