4140 Seamless Tubing for Mechanical & Industrial Applications

4140 Alloy Steel Tube Overview

AISI 4140 and SAE 4140 are chromium-molybdenum alloy steel grades commonly used for demanding mechanical applications. 4140 tube is typically supplied as seamless mechanical tubing where strength, toughness and machinability are important.

4140 Tube Specifications

Item	Specification
Material	AISI 4140 / SAE 4140
Product Type	Seamless Alloy Steel Tube
Tube Type	Mechanical Tubing
Manufacturing	Hot Finished / Cold Finished
Shape	Round Tube
Outside Diameter	Customized
Wall Thickness	Customized
Length	Standard or Customized
Delivery Condition	Annealed, Normalized, Quenched & Tempered or as Required
Surface	Black, Bright, Polished or as Required
Processing	Cutting, CNC Machining, Heat Treatment and Other Services
Inspection & Documents	MTC, EN 10204 3.1 Available
Packaging	Seaworthy Export Packing or Customized

4140 mechanical tubing can be supplied according to the required outside diameter, wall thickness, length and delivery condition. Specific dimensions should be confirmed according to the applicable product standard and order requirements.

Chemical Composition

C	Mn	Si	Cr	Mo
0.38–0.43%	0.75–1.00%	0.15–0.35%	0.80–1.10%	0.15–0.25%

The applicable chemical composition depends on the specified standard and product requirements. Actual values are confirmed by the mill test certificate.

4140 Tube Mechanical Properties

Condition	Tensile Strength	Yield Strength	Hardness
Annealed	According to applicable specification	According to applicable specification	According to delivery condition
Quenched & Tempered	According to specified condition	According to specified condition	According to specified condition

For applications requiring defined mechanical properties, the required heat treatment or delivery condition should be specified when ordering.

4140 Tube Heat Treatment

4140 is suitable for heat treatment to achieve different combinations of strength, hardness and toughness.

Heat Treatment	Typical Purpose
Annealing	Improve machinability and reduce hardness
Normalizing	Refine the structure and provide a uniform condition
Quenching & Tempering	Increase strength and hardness while maintaining toughness
Stress Relieving	Reduce residual stresses after machining or fabrication

The appropriate heat treatment condition can be supplied according to the intended application and required mechanical properties.

4140 Tube Applications

4140 steel tube is used in mechanical and industrial applications such as:

• Hydraulic cylinders and components
• Shafts and axles
• Gears and drive components
• Heavy machinery
• Automotive and agricultural equipment
• Industrial mechanical components

Its combination of strength, toughness and heat-treatment capability makes it suitable for components exposed to high loads, impact and repeated mechanical stress.

4140 Tube Supply & Processing

CJM Steel supplies 4140 steel tube for international distributors, machinery manufacturers, fabricators and industrial projects.

Available supply and processing services include:

• Customized tube dimensions and lengths
• Cutting
• CNC machining
• Heat treatment
• Surface processing
• Inspection
• Mill Test Certificate (MTC)
• EN 10204 3.1 documentation
• Seaworthy export packaging

4140 tube can be supplied according to project requirements for material condition, dimensions, quantity, processing and inspection.

For a quotation, please provide the outside diameter, wall thickness, length, quantity and required delivery condition, together with any processing or documentation requirements.

Frequently Asked Questions

What is 4140 steel tube?

4140 steel tube is a seamless alloy steel tube made from AISI/SAE 4140 chromium-molybdenum steel. It is commonly used for mechanical and industrial components requiring high strength and toughness.

Is 4140 tube seamless?

Yes. 4140 is commonly supplied as seamless mechanical tubing, including hot-finished and cold-finished forms depending on the required specification.

Is 4140 equivalent to 42CrMo4?

AISI/SAE 4140 is commonly compared with 42CrMo4 (1.7225) as a close equivalent alloy steel grade. The exact equivalence should be confirmed against the applicable standard and chemical requirements.

Is 4140 available as pipe?

Yes. 4140 can also be supplied in seamless pipe forms for applications requiring pipe products. However, 4140 steel tube is commonly specified for mechanical tubing applications.

Can CJM Steel supply 4140 steel tube?

Yes. CJM Steel supplies 4140 alloy steel tube with customized dimensions, heat treatment, cutting, machining, inspection and export support according to project requirements.

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