Product Details

ASTM A29 4140 Steel Tube: Hot Rolled Carbon Alloy Seamless Steel Pipe for Automobile
Introduction
The ASTM A29 4140 steel tube is a hot rolled carbon alloy seamless steel pipe primarily used in the automotive industry. This article provides an overview of the material, its specifications, key features, chemical composition (presented in a table), mechanical properties (presented in a table), steel grade, applications, and possible alternative grades.
Material
The ASTM A29 4140 steel tube is made from carbon alloy steel and is known for its excellent strength, toughness, and wear resistance. It is widely used in various automotive applications where high strength and durability are required.
Specification
The ASTM A29 4140 steel tube is available in seamless form and is typically manufactured according to the following specifications:
- Size Range: Outer diameter ranging from 3/8" to 4" and wall thickness ranging from 0.028" to 0.500"
- Length: Customizable, typically ranging from 6 to 24 feet
- Heat Treatment: Annealed, normalized, or quenched and tempered as required
- Surface Finish: Black, bare, or phosphate coated
Key Features
The key features of the ASTM A29 4140 steel tube include:
- High Strength: It exhibits excellent strength characteristics, making it suitable for applications that require heavy mechanical loads.
- Toughness: The steel tube possesses good toughness, enabling it to withstand harsh operating conditions and resist deformation or breakage.
- Wear Resistance: 4140 steel exhibits exceptional wear resistance, making it suitable for applications involving abrasive materials or environments.
- Machinability: It can be easily machined and lends itself well to various fabrication processes, enhancing its versatility.
- Weldability: ASTM A29 4140 steel tube can be welded using common techniques, further expanding its potential applications.
Chemical Composition
The chemical composition of ASTM A29 4140 steel tube is as follows:
Element | Carbon (C) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Silicon (Si) | Chromium (Cr) | Molybdenum (Mo) |
Percentage | 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 |
Mechanical Properties
The mechanical properties of ASTM A29 4140 steel tube are as follows:
Property | Value |
Tensile Strength | 95,000 - 105,000 psi |
Yield Strength | 60,000 - 70,000 psi |
Elongation | 25% (in 2 inches) |
Reduction in Area | 50% |
Hardness | 217 (Brinell), 95 (Rockwell C) |
Steel Grade
The steel grade ASTM A29 4140 corresponds to the American standard designation for this steel pipe. It is a widely accepted grade for automotive applications, known for its high strength and durability.
Application
The ASTM A29 4140 steel tube finds widespread application in the automotive industry, especially in the manufacturing of:
- Axle shafts
- Crankshafts
- Suspension components
- Connecting rods
- Gears and gear shafts
- Steering components
Its high strength and superior toughness make it suitable for such critical applications where reliability and performance are paramount.
Possible Alternative Grades
While ASTM A29 4140 steel tube is commonly used, there are alternative grades available that may suit specific application requirements. Some possible alternative grades include:
- ASTM A519 4140: A similar seamless steel tube with slightly different chemical composition and mechanical properties.
- ASTM A513 4140: A welded or seamless mechanical tubing variant with comparable strength and toughness.
- AISI 4340: A nickel-chromium-molybdenum alloy steel offering higher strength and improved hardenability, but at a higher cost.
- AISI 1020: A low carbon steel with good machinability but lower strength compared to 4140. Suitable for less demanding applications.






Haiyan Sanxin Steel Pipe Factory is a leading manufacturer of steel pipes in China. Located in a region with excellent geographical advantages, the factory is situated close to the Zhoushan Port and Ningbo Port.
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Q: Are you trading company or manufacturer ?
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Q: How long is your delivery time?
A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock, it is according to quantity.
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Q: What is your terms of payment ?
A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.
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Company Profile
Who We are ?
TORICH is an enterprise that has been producing precision steel
pipes and steel pipe processing for over 20 years, with a factory
area of approximately 20000 square meters
The main products produced are carbon steel and alloy steel grade
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As of 2023, TORICH has perfectly cooperated with more than 50
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What products we do?
------- Invent and produce various Precision Steel Pipes
Our steel pipes cover the following ranges:
Seamless Precision Steel Pipes
Welded Precision Steel Pipes, with DOM production
Seamless Heat Exchanger Steel Pipe
Seamless Boiler Steel Pipes
Seamless Structural Steel Pipes
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Seamless Alloy Steel Tubes & Pipes
Seamless Stainless Steel tubes
Welded Stainless Steel Tubes
Seamless Stainless Steel Tubes & Pipes
Welded Stainless Steel Tubes & Pipes
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Nickel Alloy Steel Tubes & Pipes
CNC Stainless Steel Parts
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CNC CopperParts
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Products Application:
Oil Cylinders
Air Cylinder,
Automotive Cylinder Liners
Boilers, Pressure Vessels
Shell & Heat Exchangers
Jack Lifting
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Agricultural Machineries