AISI 4340 Alloy Steel Parts Manufacturing
Precision Machining for High-Strength Engineering Applications
Unlock the potential of AISI 4340 alloy steel with our advanced CNC machining services. We deliver robust, fatigue-resistant, and high-performance components for demanding industries.
What is AISI 4340 Alloy Steel?
AISI 4340 is a low-alloy, high-strength steel renowned for its toughness, ductility, and fatigue resistance. It is widely used in critical structural applications where high strength and impact resistance are essential. The alloy's versatility makes it a top choice for aerospace, automotive, and heavy machinery industries.
- •Excellent toughness and ductility
- •High tensile and yield strength
- •Superior fatigue and impact resistance
- •Good hardenability and wear resistance
- •Suitable for heat treatment and surface hardening
Material Composition
| Element | Value |
|---|---|
| Carbon (C) | 0.38–0.43% |
| Manganese (Mn) | 0.60–0.80% |
| Silicon (Si) | 0.15–0.30% |
| Chromium (Cr) | 0.70–0.90% |
| Nickel (Ni) | 1.65–2.00% |
| Molybdenum (Mo) | 0.20–0.30% |
| Phosphorus (P) | ≤0.035% |
| Sulfur (S) | ≤0.040% |
Key Mechanical Properties
Key Mechanical Properties
- •Tensile Strength: 930–1080 MPa (after heat treatment)
- •Yield Strength: 740–930 MPa
- •Elongation: 12–16%
- •Hardness: 24–32 HRC
- •Density: 7.85 g/cm³
- •Excellent toughness and fatigue resistance
Machining & Processing Capabilities
AISI 4340 can be precisely machined using advanced CNC equipment. The alloy responds well to turning, milling, drilling, and grinding, especially after proper heat treatment. Our facility is equipped for tight-tolerance, high-complexity parts, and we offer surface treatments such as nitriding, carburizing, and induction hardening for enhanced performance.
CNC Turning & Milling
Deep Hole Drilling
Surface & Cylindrical Grinding
Heat Treatment & Quenching
Surface Hardening (Nitriding, Carburizing)
Precision Inspection & Testing
Typical Applications
Aerospace
Landing gear, engine shafts, and structural components requiring high strength and toughness.
Automotive
Crankshafts, gears, and drive shafts for performance and heavy-duty vehicles.
Industrial Equipment
Press rams, axles, and high-stress machine parts.
Oil & Gas
Drill collars, tool joints, and downhole equipment.
Why Choose Us for AISI 4340 Parts?
Expertise in high-strength alloy steel machining
Advanced CNC and heat treatment capabilities
Comprehensive quality control and certification
Fast turnaround and global shipping
Quality Assurance
We adhere to strict quality standards, including ISO 9001:2015 and AS9100D. All AISI 4340 parts undergo rigorous inspection, material traceability, and mechanical property verification. Non-destructive testing (NDT) and full documentation are available upon request.
Frequently Asked Questions
What is AISI 4340?
What is the material equivalent to AISI 4340?
Is 4340 the strongest steel?
Is 4340 steel or aluminum?
What is the material composition of AISI 4340 steel?
Start Your AISI 4340 Project Today!
Contact us for expert alloy steel machining and fast, reliable delivery.