Smooth AISI 4140 Carbon Steel HB 197 - 241 4140 Low Alloy Steel With High Fatigue Strength

AISI 4140 Alloy is a versatile low-alloy steel known for high strength, toughness, and wear resistance. This widely used alloy offers an excellent balance of mechanical properties and ease of heat treatment, making it ideal for applications requiring high fatigue strength, impact resistance, and good machinability.

• Carbon (C): 0.38-0.43% - Provides optimal strength-to-toughness balance for effective heat treatment
• Manganese (Mn): 0.75-1.00% - Enhances hardenability and tensile strength
• Chromium (Cr): 0.80-1.10% - Increases corrosion resistance, hardness, and wear resistance
• Molybdenum (Mo): 0.15-0.25% - Improves high-temperature strength and hardenability
• Silicon (Si): 0.15-0.35% - Contributes to overall strength and deoxidation
• Phosphorus (P): ≤0.035% - Maintains toughness and reduces brittleness
• Sulfur (S): ≤0.040% - Minimizes inclusions for improved machinability

• Tensile Strength: 655-850 MPa (after heat treatment) - Withstands heavy loads and stress
• Yield Strength: ≥415 MPa - Resists permanent deformation under stress
• Elongation: ≥20% - Offers excellent formability without cracking
• Density: 7.85 g/cm³ - Provides balanced strength-to-weight ratio
• Hardness: HB 197-241 (as annealed) - Base hardness suitable for further treatment
• Impact Toughness: High resistance to dynamic and cyclic loading

• Annealing: Improves machinability and restores ductility
• Normalizing: Refines grain structure for enhanced strength
• Quenching and Tempering: Increases hardness for high-stress applications
• Carburizing: Creates wear-resistant surface with tough core

• Automotive: Gears, crankshafts, connecting rods requiring fatigue resistance
• Oil & Gas: Downhole tools, drill collars, pipe joints needing toughness
• Machinery: Shafts, axles, bolts under heavy cyclic stress
• Tool & Die: High-strength tools, dies, molds demanding wear resistance
• Construction: Heavy-duty equipment requiring impact resistance