Difference between 1018 steel and 1045 steelBy Sumit Impex / May 12, 2023 1018 steel vs 1045 steel Property1018 Steel1045 SteelCarbon (C) Content0.15 – 0.20%0.43 – 0.50%Manganese (Mn) Content0.60 – 0.90%0.60 – 0.90%Phosphorus (P) Content0.04% max0.04% maxSulfur (S) Content0.05% max0.05% maxMechanical Properties Yield StrengthAround 370 MPaAround 450 MPaTensile StrengthAround 440 MPaAround 650 MPaElongation at BreakAround 20%Around 12%Hardness, BrinellApproximately 120Approximately 180Machinability Rating0.70.64WeldabilityExcellentModerate