AISI/SAE 4140 Hot Rolled (HR) is a high-strength chromium-molybdenum alloy steel, designed for applications requiring a combination of strength, toughness, and wear resistance. The hot rolling process enhances its workability and ability to handle high-stress conditions while maintaining good dimensional tolerance. 4140 is widely used in both hardened and unhardened forms, providing excellent mechanical properties, such as toughness, fatigue resistance, and impact strength, after heat treatment.
2. Applications/Industries
Automotive (e.g., crankshafts, axles, gears)
Aerospace (e.g., shafts, structural components)
Industrial Machinery (e.g., spindles, tooling)
Oil & Gas Equipment (e.g., drill collars, pumps)
Power Transmission Components (e.g., couplings, gears)
Heavy Equipment
3. Certifications/Standards
Meets ASTM A29 standards
Meets SAE 4140 specifications
ISO 9001 certified
4. Chemical Composition
Carbon (C): 0.38–0.43%
Manganese (Mn): 0.60–0.90%
Chromium (Cr): 0.80–1.10%
Molybdenum (Mo): 0.15–0.25%
Phosphorus (P): ≤ 0.035%
Sulfur (S): ≤ 0.04%
5. Technical Specifications
Yield Strength: 650–900 MPa (depending on heat treatment)
Tensile Strength: 900–1100 MPa
Hardness: 200–250 HB (Brinell Hardness)