Aobo Steel

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Aobo Steel supply 4140 steel for your project

Premium 4140 Steel Supplier for Unmatched Durability

As your trusted 4140 steel supplier, we at Aobo Steel are excited to offer you top-quality 4140 steel—a material that truly stands out for its strength, toughness, and wear resistance. Its unique blend of chromium, molybdenum, and carbon makes it the go-to choice for heavy-duty applications like gears, shafts, and machinery parts. Here’s the best part: we don’t just supply steel; we deliver solutions. Whether you need precision machining, heat treatment, or custom fabrication, our team is here to ensure you get exactly what you need.

4140 Steel: The Perfect Blend of High Strength and Versatility

As a leading supplier of 4140 steel, Aobo Steel proudly offers you exceptional 4140 steel, a chromium-molybdenum alloy renowned for its impressive strength, toughness, and wear resistance. Whether you need it for automotive gears, aerospace components, or heavy machinery parts, 4140 steel rises to the challenge. By choosing Aobo Steel, you’ll receive top-quality materials and expert service that are perfectly tailored to meet even your most demanding application needs.

Aobo Steel: Your One-Stop Solution for 4140 Steel

As an industry-leading distributor of 4140 steel, Aobo Steel supplies high-quality materials and delivers comprehensive technical support and services. From heat treatment recommendations to machining guidance, we ensure you can fully harness the outstanding properties of 4140 steel. Choose Aobo Steel, and watch your projects become more efficient and reliable.

Suply Range

Shape	Size	Length	Surface finish	tolerance
round bar	diameter 20mm-400mm	length 2500mm-5800mm	black	0/+5mm
			peeled	0/+5mm
			turned(machined)	0/+2mm
plate	widththickness 100mm-800mm10mm-400mm	length 2500mm-5800mm	black	0/+5mm
			peeled	0/+5mm
			turned(machined)	0/+2mm

4140 steel Chemical Composition

Carbon (C)	Manganese (Mn)	Phosphorus (P)	Sulfur (S)	Silicon (Si)	Chromium (Cr)	Molybdenum (Mo)
0.38% – 0.43%	0.75% – 1.00%	≤ 0.035% (max)	≤ 0.040% (max)	0.15% – 0.35%	0.80% – 1.10%	0.15% – 0.25%

4140 steel Equivalent Grades

Country	Standard	Grade
USA	ASTM A29/A29M	4140 (G41400)
Europe	EN 10083-3	42CrMo4 (1.7225)
China	GB/T 3077	42CrMo
Japan	JIS G 4105	SCM440
UK	BS 970	708M40

4140 steel heat treatment

Quenching

Quenching Temperature: Typically heated to 845°C (1550°F) or 855°C (1570°F), followed by oil quenching.
Quenching Medium: Oil quenching is recommended to achieve higher quenching hardness (approximately 54-59 HRC).
Quenching Hardness: After quenching, the hardness can reach 54-59 HRC, depending on carbon content and quenching conditions.

Tempering

Tempering Temperature: Usually set between 480-595°C (950-1100°F) based on the required hardness range.
- For example, tempering at 480-595°C results in a hardness of 25-32 HRC.
- Tempering at 316°C (600°F) for higher hardness can achieve a tensile strength of 225 ksi.
Tempering Time: Typically 2 hours, but can be adjusted according to part size and performance requirements.

Normalizing

Normalizing Temperature: Heated to 913°C (1675°F), followed by air cooling to improve material uniformity and mechanical properties.
Normalizing Effects: Refining grain structure, enhancing toughness, and improving machinability.

Annealing

Annealing Temperature: Typically heated to 872°C (1600°F), then slowly cooled (furnace cooling).
Purpose of Annealing: Reduces hardness, enhances machinability, and prepares the material for further heat treatment.

Other Heat Treatment

Forging Temperature: Recommended between 926-1205°C (1700-2200°F).
Hot Working Temperature: Can be performed within the range of 816-1038°C (1500-1900°F).

Properties After Heat Treatment

Hardness: After quenching, the hardness can reach 54-59 HRC. After tempering, it can be adjusted to 25-32 HRC based on requirements.
Mechanical Properties:
- Tensile Strength: 1080 MPa
- Yield Strength: 930 MPa
- Elongation: 12%
Impact Toughness:
- Tempering at 580-620°C significantly improves impact toughness, increasing from 55 J to 108 J.

4140 steel Applications

Automotive Industry

- Gears and Shafts: Manufacturers craft these for transmissions, axles, and drivetrains because 4140 steel is extremely strong and resists fatigue well.

- Crankshafts: Engineers love using them in engines since they handle high-stress situations without breaking a sweat.

- Suspension Components: Mechanics rely on it to build parts like tie rods and steering knuckles, keeping everything sturdy and reliable on the road.

Aerospace Industry

- Landing Gear Components: Designers chose 4140 steel here because its high strength-to-weight ratio keeps planes safe and light.

- Engine Mounts: Meanwhile, builders use it for mounts since it’s super durable and shrugs off fatigue over time.

Oil and Gas Industry

- Drill Collars and Tools: Workers depend on this steel in drilling gear because it’s tough and fights off wear like a pro.

- Valve Components: Engineers use it for stems and bodies, especially in high-pressure setups, because it withstands intense conditions.

Machinery and Equipment

- Hydraulic Cylinders: Manufacturers swear by 4140 steel here because it’s strong and handles sky-high pressure without flinching.

- Machine Tool Frames: It’s also a go-to for frames thanks to its rigidity and knack for soaking up vibrations.

- Bolts and Fasteners: Fabricators use it to make high-strength bolts that keep heavy machinery locked tight.

Tooling and Dies

- Molds and Dies: Toolmakers shape these for plastic injection molding and die-casting because 4140 steel withstands heat and pressure.

- Tool Holders: Machinists grab it for holders since it’s durable enough to survive tough jobs.

Construction and Heavy Equipment

- Crane Hooks and Chains: Builders trust 4140 steel to handle massive loads without bending or snapping.

- Excavator Bucket Teeth: It’s perfect for these parts since they resist wear and stay tough, even in brutal conditions.

General Engineering

- Sprockets and Couplings: Designers whip these up for power transmission systems because 4140 steel keeps things running smoothly.

Pump Shafts and Housings: Finally, engineers turn to it for high-pressure, high-wear setups since it’s built to last.