High-Strength Chromium-Molybdenum Alloy Plates | EN10083-3 / ASTM A29 / A322 Standards

AISI 4140 Alloy Steel Plate Overview

AISI 4140 alloy steel plate is a widely used chromium-molybdenum alloy steel known for its excellent balance of strength, toughness, and hardenability. As a medium-carbon Cr-Mo steel, 4140 steel is commonly selected for heavy-duty mechanical and structural components requiring reliable performance under load.

This grade is supplied in accordance with major international standards including ASTM A29 / A322 (4140), SAE 4140, and EN 42CrMo4, making it a versatile choice for global engineering and industrial projects.

As the reference grade within this alloy family, 4140 alloy steel plate serves as the baseline for comparing alternative grades such as AISI 4135, AISI 4142, and AISI 6150, which are selected when specific machining, hardness, or fatigue requirements apply.

For detailed technical background, please refer to:

🔗4140 Steel Technical Guide: Properties, Composition and Equivalents

🔗4140 Steel: Properties, Applications & Heat Treatment Guide

Product Parameters – Alloy Steel Plate Supply Range

Product Name	AISI 4140 Alloy Steel Plate (Alternative: 4135 / 4142 / 6150)
Production Process	Hot Rolling, Cold Rolling
Material Standards	AISI, ASTM, ASME, DIN, BS, EN, ISO, JIS, GOST, SAE
Width	100mm-3000mm
Length	1m-12m, or Customized Size
Thickness	0.1mm-400mm
Delivery Conditions	Rolling, Annealing, Quenching, Tempered or Standard
Surface Finish	Black, Machined, Ground, Film Coated

Chemical Composition of 4140 and Related Alloy Steel Grades

The following table compares 4140 steel with commonly requested alternative grades, highlighting their compositional differences and selection focus.

Brand	C	Si max	Mn	P max	S max	Cr	Mo	V	Key Features
AISI 4135 / 34CrMo4	0.3-0.37	0.40	0.6-0.9	0.025	0.035	0.9-1.2	0.15-0.3	–	Good machinability, balanced strength
AISI 4140 / 42CrMo4	0.38-0.45	0.40	0.6-0.9	0.025	0.035	0.9-1.2	0.15-0.3	–	High tensile strength, versatile performance
AISI 4142 / 50CrMo4	0.46-0.54	0.40	0.5-0.8	0.025	0.035	0.9-1.2	0.15-0.3	–	Higher hardness, better wear resistance
AISI 6150 / 51CrV4	0.47-0.55	0.40	0.7-1.1	0.025	0.025	0.9-1.2	–	0.1-0.25	Excellent fatigue strength, Cr-V alloy

Mechanical Properties of Alloy Steel Plates

Grade	Thickness (mm)	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)	Reduction of Area (%)	Impact Energy KV2 (J)	Typical Applications
AISI 4135	≤ 80	850	950–1150	16	45–60	40–70	Shafts, gears, axles with higher machinability
AISI 4140	≤ 80	900	1000–1300	14	40–60	35–70	Crankshafts, coupling rods, heavy-duty fasteners
AISI 4142	≤ 80	950	1050–1350	13	35–55	30–60	Dies, molds, wear-resistant parts
AISI 6150	≤ 80	850	1100–1300	13	40–55	45–65	Springs, torsion bars, mechanical components under fatigue
All Grades (100–160 mm)	100–160	800–850	950–1200	12	30–50	25–55	Forged, machined, or structural parts

Design & Procurement Insight

• AISI 4140 offers the best all-around performance and is the preferred choice for over 80% of industrial uses.
• AISI 4135 is more cost-effective where moderate strength and excellent machinability are required.
• AISI 4142 provides enhanced surface hardness after heat treatment, ideal for tooling or wear parts.
• 6150 alloy steel plate, strengthened by vanadium, is ideal for fatigue-critical components.

Based on current demand, we also support wholesale 6150 alloy plate supply and customized 6150 cold drawn profiles for export-oriented buyers seeking stable quality and competitive pricing.

Typical Applications of 4140 Alloy Steel Plate

4140 steel plate is widely used across industries including:

• Heavy machinery: shafts, gears, couplings, high-strength fasteners
• Automotive & transport: crankshafts, transmission components
• Energy & oilfield: drill collars, pressure-bearing parts
• General engineering: forged parts, structural components

Why Choose CJM as Your 4140 Alloy Steel Plate Supplier

✅ Certified Quality – Supplied with EN 10204 3.1 mill certificates, ensuring full traceability and quality compliance.
✅ Flexible Supply Condition – Available annealed for machining or quenched & tempered for direct use.
✅ Custom Processing – Precision cutting, grinding, and heat treatment available upon request.
✅ Stable Supply Chain – We maintain strategic 4140 plate stock, ensuring faster delivery and consistency for both standard and special grades.

Looking for bar products? Visit our AISI 4140 Alloy Steel Bar page for round and forged bar options.

Packaging & Export Delivery

4140 alloy steel plate is securely packed for export using steel strapping, wooden pallets, and moisture protection to ensure safe international transportation.

Request a Quote – 4140 Alloy Steel Plate

Looking for a fair price on 4140 alloy steel plate or 6150 alloy plate?

Contact CJM Steel today for a competitive quotation with certified quality, reliable delivery, and professional export support.
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Q: What is your company’s main products/services?

A: We are a professional manufacturer for Carbon Steel, Alloy Steel and Profile products. We have the experience of steel business for more than 10 years and our products are exported to Mid East,South America,Southeast Asia,Africa,South and East Asia etc.

Q: Can I go to your factory for a visit?

A: Of course, we welcome customers from all over the world to visit our factory.

Q: What are your terms of payment?

A: 30% T/T deposite and 70% balance before shipment.

Q: What is your delivery time?

A: For stocks,we could transport the goods to loading port within 7 days after we received the deposit; For production,it usually takes about 15-30 days after receiving the deposit.

Q: Do you provide samples? Are they free or paid?

A: Samples are available for free,but the courier freight will be covered by customer account.

Q: Do you accept the third party inspection?

A:Yes, we fully accept ‌third-party inspections.

Q: Why should I buy from you not from other suppliers?

A: Integrating the superior resources of China’s steel industry, we provide customers with high-quality steel products at preferential prices, and can ensure that the goods are delivered to customers in a timely manner.

Q:How can you guarantee quality?

A: Always a pre-production sample before mass production;Always 100% inspected before shipment