... relaxation, high tensile strength, pre-stressing steel wire for pre-cast pre-stressed concrete Specification:Diameter: 2.9, 3.0, 3.5, ... for pre-stressed concrete (ULBON)Material: Steel wire rod grade 30MnSiSize: 5.0mm, 6.0mm, 7.1mm, 9.0mm, 10.7mm, 12.6mm Standard: YB ... N/mm2Elongation 5.0% min, Straightness 2.0mm/m maxNormal Relaxation 4.0% max, Low Relaxation 2.0% maxFeature: low relaxation, high ...