Alloy Steel Bar made in China Introduction Alloy steel round bar 4140. Few grades can match the practicality and adaptability of 4140 due to its tensile strength, high fatigue strength, and abrasion and impact resistance. Chemical Component CCrMnSiMoSPFe 0.38-.43%0.80-1.10%0.75-1.0%0.15-0.30%0.15-0.25%0.040% max0.035% maxBalance Mechanical Property PropertiesMetricImperial Tensile strength655 MPa95000 psi Yield strength415 MPa60200 psi Bulk modulus (typical for steel)140 GPa20300 ksi Shear modulus (typical for steel)80 GPa11600 ksi Elastic modulus190-210 GPa27557-30458 ksi Poisson's ratio0.27-0.300.27-0.30 Elongation at break (in 50 mm)25.70%25.70% Hardness, Brinell197197 Hardness, Knoop (converted from Brinell hardness)219219 Hardness, Rockwell B (converted from Brinell hardness)9292 Hardness, Rockwell C (converted from Brinell hardness. Value below normal HRC range, for comparison purposes only)1313 Hardness, Vickers (converted from Brinell hardness)207207 Machinability (based on AISI 1212 as 100 machinability)6565 Details Product NameAlloy Steel Round Bar 4140 StandardAISI,ASTM, EN, BS, GB, DIN, JIS Diameter10mm-1200mm TechnologyHot rolled, Cold rolled, Forged SurfacePolished bright, black InspectionISO,BV,SGS,MTC Supply Ability1000 metric tons/month Shipment timeWithin 7-10 workdays after receiving deposit . PaymentsT/T, LC Our Advantages 1.easy to installation 2.Strict quality management system 3.Superior equipment 4.Professional services 5.OEM/ODM services 6.High quality products Quality inspection before delivery If you have another question, pls feel free to contact us .Alloy Steel Bar made in China website:http://www.cnaluminumalloy.com/alloy-steel/alloy-steel-bar/