4140 Bored Tube
The 4140 Bored Tube is a high-strength alloy steel tube widely used in heavy-duty hydraulic cylinder applications. Manufactured from AISI 4140 steel, this material offers a combination of toughness, wear resistance, and fatigue strength, making it ideal for demanding mechanical environments. The tube is processed through boring, honing, and precision machining to achieve the required internal diameter and surface finish suitable for hydraulic and pneumatic cylinder barrels.
EASTAI supplies 4140 Bored Tubes with excellent dimensional accuracy, uniform hardness, and high concentricity. Each tube is produced under strict metallurgical control to ensure stability and performance in heavy equipment, construction machinery, and mining systems.
Model:Bored Tube
Brand:EAST AI
Material:4140
Product Description
Advantages of 4140 Bored Tube
The 4140 Bored Tube provides a number of advantages that make it superior for high-load applications:
High Strength and Toughness – 4140 alloy steel provides exceptional yield and tensile strength, maintaining stability under high pressure.
Excellent Fatigue Resistance – Suitable for dynamic load environments such as hydraulic cylinders and mining actuators.
Good Machinability – Despite its strength, 4140 steel machines well, allowing precision honing and boring.
Uniform Hardness – Ensures consistent performance across the tube length, minimizing deformation and wear.
Corrosion and Wear Resistance – Enhanced surface finish reduces friction and prevents internal damage from seals or pistons.
Customizable Dimensions – Available in various outer diameters, inner diameters, and wall thicknesses to meet customer requirements.
Production Process of 4140 Bored Tube
EASTAI follows a rigorous and standardized production process to ensure every 4140 Bored Tube meets global industrial standards.
Process Step | Description |
Raw Material Selection | Premium 4140 alloy steel billets are sourced with controlled chemistry and purity. |
Hot Rolling / Forging | Steel billets are hot rolled or forged into thick seamless tubes. |
Heat Treatment (Quenching & Tempering) | Tubes are heat-treated to achieve optimized hardness (HRC 25–32) and toughness. |
Boring / Deep Hole Drilling | The inner diameter is precisely bored to achieve concentricity and required ID tolerance. |
Honing or Skiving & Roller Burnishing | Internal surface is finished to achieve a smooth surface with Ra ≤ 0.4 μm. |
Straightening and Sizing | Ensures linear accuracy and consistent wall thickness. |
Inspection and Packaging | Each tube undergoes dimensional, hardness, and visual inspection before delivery. |
EASTAI’s advanced boring machines and honing lines guarantee tight dimensional tolerance (up to ±0.03mm) and excellent surface roundness, ensuring compatibility with various hydraulic piston rod assemblies.
Applications of 4140 Bored Tube
The 4140 Bored Tube is extensively used in hydraulic and pneumatic cylinder manufacturing, as well as in industrial and heavy mechanical applications requiring strength and precision. Common applications include:
Hydraulic Cylinder Barrels for construction and agricultural machinery
Excavators and Loaders hydraulic systems
Mining Equipment such as rock drills and haul trucks
Industrial Presses and Injection Machines
Marine and Offshore Platforms requiring corrosion-resistant internal surfaces
Heavy Lifting Equipment and mobile cranes
The mechanical properties of 4140 bored tubes make them ideal for high-pressure environments and long service life requirements.
Product Details of 4140 Bored Tube
Parameter | Specification |
Material Grade | AISI 4140 / DIN 42CrMo4 |
Condition | Quenched and Tempered |
Hardness | HRC 25–32 |
Outer Diameter (OD) | 50mm – 500mm |
Inner Diameter (ID) | 40mm – 480mm |
Wall Thickness | 5mm – 60mm |
Length | Up to 8 meters |
Surface Roughness (Ra) | ≤ 0.4 μm |
Straightness | ≤ 0.3mm/m |
Tensile Strength | 850 – 1000 MPa |
Yield Strength | ≥ 650 MPa |
Application Standard | DIN 2391 / EN 10305 / ASTM A519 |
Factory Inventory and Supply Capacity of 4140 Bored Tube
EASTAI maintains a large stock of 4140 Bored Tubes in various sizes to ensure rapid delivery to global customers.
Inventory: Over 10,000 tons of ready-to-ship hydraulic tubing
Delivery Time: Within 7–10 days for standard sizes
Customization: Fast machining and honing available for special dimensions
Packaging: Anti-rust oil coating and seaworthy export packaging
The company’s 8,000 m² warehouse and automatic storage system guarantee short lead times and stable supply for distributors and OEM factories.
Quality Inspection of 4140 Bored Tube
EASTAI implements comprehensive testing procedures to ensure each 4140 bored tube meets performance and safety standards.
Dimensional Inspection: OD, ID, and wall thickness checked with high-precision instruments
Surface Roughness Test: Ra values tested after honing or burnishing
Hardness Test: HRC values confirmed after heat treatment
Ultrasonic Testing (UT): To ensure no internal cracks or inclusions
Straightness and Roundness Inspection: Conducted using laser alignment tools
Hydrostatic Test (if required): Verifies pressure resistance for hydraulic use
These steps ensure that every EASTAI 4140 Bored Tube is reliable and ready for immediate cylinder assembly.
Certificates of 4140 Bored Tube
EASTAI’s 4140 Bored Tubes comply with multiple international standards and have been certified by leading inspection agencies:
GL (Germanischer Lloyd) – Approval of Material Manufacturers (AMM)
ISO 9001:2015 Quality Management System
Material Mill Certificates (EN 10204 3.1/3.2)
Third-Party Inspections: SGS / BV / TUV available upon request
These certifications demonstrate EASTAI’s commitment to quality, traceability, and global compliance.
