Q355B Honed Tube

What Is Q355B Honed Tube?

Q355B Honed Tube is a seamless carbon steel tube made from Q355B structural steel, known for its excellent strength, weldability, and formability. The tube is internally honed to achieve a smooth surface (Ra ≤ 0.2 μm) and ISO H8 tolerance, making it ideal for use as Hydraulic Cylinder Tubing.

This product is specifically engineered to be used as the inner body of a Hydraulic Cylinder Barrel, where precision and wear resistance are critical for performance and reliability. Q355B offers a strong balance between mechanical properties and price, making it an excellent alternative to more expensive alloy steels like 4140.

Key Features

• Material: Q355B carbon structural steel

• Inner surface finish: Ra ≤ 0.2 μm

  Inner diameter tolerance: ISO H8

• Yield strength: ≥ 355 MPa

• Wall thickness range: 5–50 mm

• Outer diameter range: 40–500 mm

• Length: Up to 6 meters or customized

• Heat treatment: As rolled or normalized

• Standard: GB/T 8713-2022

Advantages of Q355B Honed Tube

• High Strength with Good Ductility
  Supports medium to high pressure hydraulic systems with reliable performance.

• Smooth Bore for Seal Compatibility
  Honed to reduce internal friction, increase seal life, and ensure leak-free performance.

• Accurate Inner Diameter
  Maintains ISO H8 tolerance, reducing piston wear and enhancing cylinder efficiency.

• Easy to Weld & Machine
  Q355B can be easily welded or modified during cylinder fabrication.

• Cost-Effective Hydraulic Cylinder Tubing
  Offers great performance at a lower price point compared to alloy grades.

Typical Applications

Q355B Honed Tube is widely used in manufacturing:

• Agricultural cylinders (lifting, steering)

• Construction cylinders (excavators, loaders, cranes)

• Factory automation equipment

• Truck-mounted cylinders and trailers

• Industrial presses and injection molding machinery

Whether you're building a single-stage Hydraulic Cylinder Barrel or a multi-stage telescopic design, Q355B provides the strength, smoothness, and accuracy your application needs.

Manufacturing Process

1. Material Preparation:
   Seamless Q355B tubes are selected for straightness and consistency.

2. Cold Drawing or Boring:
   Optional, to improve wall thickness uniformity.

3. Skiving:
   Removes imperfections and ensures a circular inner diameter.

4. Honing:
   Achieves a smooth finish (Ra ≤ 0.2 μm) and ISO H8 precision.

5. Inspection:
   Includes dimensional, roughness, straightness, and ultrasonic tests.

6. Surface Protection:
   Coated with anti-rust oil or VCI film.

7. Packaging:
   End capped, bundled, and labeled for traceability.