GB4357-1989 Round cold-drawing carbon spring steel wire for machinery.Tolerance Of Steel WireDiameter of steel wire (mm) Tolerance(mm)>0.1-0.30 >0.3-0.60 >0.6-1.00 >1.0-3.00 >3.0-5.0±0.014 ±0.018 ±0.02 ±0.03 ±0.038Torsion Performance Diameter of steel wire (mm) Torsion frequency not less thanGrade B.C≤2.00 >2.00-3.0020 15Coiling PerformanceGrade of steel wire of steel wire (mm)Core rod diameter(mm)Tuming rounds of coiling Grade B.C≤6.00d≥2There shall not be cracks and ruptures on the sample surface atter coiling.Tensile Strengthg Of Spring Wire Diameter(mm) Tensile strength(MPa)Grade BGrade C0.222110-25002350-27500.252060-24502300-27000.282010-24002300-27000.302010-24002300-27000.321960-23502250-26500.351960-23502250-26500.401910-23002250-26500.451860-22602200-26000.501860-22602200-26000.551810-22102150-25500.601760-21602110-25000.631760-21602110-25000.701710-21102060-24500.801710-20602010-24000.901710-20602010-23501.001660-20101960-23001.201620-19601910-22501.401620-19101860-22101.601570-18601810-21601.801520-18101810-21102.001470-17601710-20102.201420-17101660-19602.501420-17101660-19602.801370-16701620-19103.001370-16701570-18603.201320-16201570-18103.501320-16201570-18104.001320-16201520-17604.501320-15701520-17605.001320-15701470-1710