Hydraulic tube

pneumaticsteelheavy-duty

Product overview
The EAST AI 4140 Bored Tube is a precision-machined alloy steel tube designed for hydraulic and pneumatic cylinder barrels. Manufactured from AISI 4140 (DIN 42CrMo4) and delivered quenched and tempered, the tube offers controlled hardness, concentricity and an internal surface finish suitable for piston seals and dynamic applications.

General information

• Model: Bored Tube
• Brand: EAST AI
• Material: 4140 (AISI 4140 / DIN 42CrMo4)
• Condition: Quenched and tempered

Advantages of 4140 Bored Tube

• Strength and toughness – 4140 alloy steel provides high yield and tensile properties appropriate for pressurized cylinder applications.
• Fatigue resistance – Suitable for dynamic loading in hydraulic systems and heavy machinery.
• Precision machining – Boring, honing and burnishing yield consistent ID tolerances and low surface roughness.
• Uniform hardness and concentricity – Ensures predictable wear behavior along the tube length.
• Optimized internal finish – Ra ≤ 0.4 μm reduces friction and extends seal life.
• Custom dimensions – Available in a wide range of OD, ID and wall thicknesses.

Production process
Raw material selection: Premium 4140 alloy billets with controlled chemistry and traceability.
Hot rolling / forging: Billets are formed into seamless tube blanks.
Heat treatment (quenching & tempering): Achieves target hardness (HRC 25–32) and required toughness.
Boring / deep hole drilling: Inner diameter is machined to tight concentricity and tolerance.
Honing / skiving & roller burnishing: Internal surface finished to Ra ≤ 0.4 μm.
Straightening and sizing: Ensures straightness and consistent wall thickness.
Inspection and packaging: Dimensional, hardness and visual inspections before packing with anti-rust protection.

Applications

• Hydraulic and pneumatic cylinder manufacturing (barrels for construction, agricultural and industrial machinery)
• Excavator, loader and heavy equipment hydraulic systems
• Mining equipment actuators and components
• Industrial presses, injection molding machines and forming equipment
• Marine and offshore hydraulic systems
• Mobile cranes and heavy lifting equipment

Product details
Material grade: AISI 4140 / DIN 42CrMo4
Condition: Quenched and tempered
Hardness: HRC 25–32
Outer diameter (OD): 50 mm – 500 mm
Inner diameter (ID): 40 mm – 480 mm
Wall thickness: 5 mm – 60 mm
Length: Up to 8 meters
Surface roughness (internal): Ra ≤ 0.4 μm
Straightness: ≤ 0.3 mm/m
Tensile strength: 850 – 1000 MPa
Yield strength: ≥ 650 MPa
Applicable standards: DIN 2391 / EN 10305 / ASTM A519

Factory inventory and supply capacity

• Large stock in multiple sizes to support short lead times.
• Typical delivery for standard sizes: short lead times (example: 7–10 days).
• Fast machining and honing services for special dimensions; export-standard packaging with anti-rust oil.
• Automated warehouse systems to ensure stable supply and rapid dispatch.

Quality inspection

• Dimensional inspection: OD, ID and wall thickness measured with high-precision instruments.
• Surface roughness testing after honing or burnishing (Ra measurement).
• Hardness testing: HRC confirmed after heat treatment.
• Ultrasonic testing (UT) to detect internal defects.
• Straightness and roundness verification using laser alignment tools.
• Hydrostatic test available on request for pressure applications.

Certificates

• 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 inspection reports (SGS / BV / TUV)

caractéristiques / spécifications techniques

• Material: AISI 4140 (DIN 42CrMo4)
• Condition: Quenched and Tempered
• Hardness: HRC 25–32
• Outer diameter range: 50 mm – 500 mm
• Inner diameter range: 40 mm – 480 mm
• Wall thickness range: 5 mm – 60 mm
• Maximum length: up to 8 meters
• Surface roughness (internal): Ra ≤ 0.4 μm
• Straightness tolerance: ≤ 0.3 mm/m
• Dimensional tolerance / concentricity: tight tolerance (example: up to ±0.03 mm for bored ID)
• Tensile strength: 850 – 1000 MPa
• Yield strength: ≥ 650 MPa
• Applicable standards: DIN 2391 / EN 10305 / ASTM A519