1. Key Properties
AISI/SAE 4140 is a low-alloy steel that offers a high combination of strength, toughness, and wear resistance. The 4140 flat bar is versatile and can be heat-treated to achieve a variety of hardness levels. It exhibits excellent fatigue resistance, impact strength, and good machinability. This steel is also known for its high tensile strength, making it suitable for heavy-duty components. Its weldability and formability make it ideal for a wide range of industrial and engineering applications.
2. Applications/Industries
Automotive: Gears, shafts, axles, and other high-stress components.
Aerospace: Structural components, turbine shafts, landing gear, and other high-performance parts.
Heavy Machinery: Crankshafts, spindles, and forged parts used in industrial machines.
Oil & Gas: Drilling tools, valve bodies, and other equipment that need to withstand harsh conditions.
Tool Manufacturing: Dies, molds, and tools requiring a combination of hardness and toughness.
Power Transmission: Shafts, couplings, and other mechanical components subjected to high stresses.
3. Certifications/Standards
ISO 9001 Certified: Ensures high-quality manufacturing standards.
Meets AISI/SAE 4140 Specifications: Conforms to American Iron and Steel Institute (AISI) and Society of Automotive Engineers (SAE) specifications for alloy steels.
Meets ASTM A29 Specifications: Adheres to the ASTM standards for alloy steel bars.
4. Chemical Composition
Carbon (C): 0.38–0.43%
Manganese (Mn): 0.75–1.00%
Chromium (Cr): 0.80–1.10%
Molybdenum (Mo): 0.15–0.25%
Phosphorus (P): ≤ 0.035%
Sulfur (S): ≤ 0.040%
Silicon (Si): ≤ 0.35%
5. Technical Specifications
Yield Strength: Approx. 650–900 MPa (depending on heat treatment)
Tensile Strength: Approx. 900–1200 MPa
Hardness: 28–32 HRC (Rockwell Hardness) (before heat treatment)
Hardness: 36–45 HRC (Rockwell Hardness) (after heat treatment)