Honed Tube

The Honed Tube is manufactured to precise dimensional, material, and mechanical specifications to ensure reliable performance in high-pressure hydraulic systems.

Dimensional Specification Table

Material Grade & Chemical Composition Table

We manufacture our honed tubes in compliance with major international standards, ensuring they are compatible with global hydraulic systems and machinery. We also support custom manufacturing based on specific customer drawings.

Chemical Composition (ASTM A519 Grade 1026):

Mechanical Properties (DIN 2391 ST52 / E355):

The production of honed tubes involves a multi-stage manufacturing process designed to enhance the physical and surface properties of the steel.

1. Seamless Tube Preparation: The process begins with a hot-rolled seamless tube, which is pickled and phosphated to clean the surface.

2. Cold Drawing: The tube is cold-drawn to achieve the approximate final dimensions and improve the material's strength.

3. Skiving and Roller Burnishing (SRB): For many applications, we use the SRB process. Skiving cuts a thin layer of metal to correct geometry, while roller burnishing compresses the surface peaks into the valleys, creating a smooth, work-hardened surface.

4. Honing: For the highest precision, we use honing stones. This abrasive process removes a minute amount of material to create the final "cross-hatch" pattern. This pattern is crucial for oil retention in hydraulic cylinders.

5. Heat Treatment: If required, the tubes undergo stress-relief annealing to ensure stability during subsequent machining by the customer.

6. Quality Control: Every tube is inspected for surface defects, dimensional accuracy, and straightness.

To preserve the high-quality surface finish of the honed tube, specialized packing methods are employed. The internal surface is delicate and must be protected from dust, moisture, and physical impact during transit.

Packing Procedures:

1. Cleaning: The tubes are thoroughly cleaned to remove metal chips and dust.

2. Oil Coating: A layer of anti-rust oil is applied to the inner and outer surfaces to prevent corrosion during storage and shipping.

3. End Capping: Plastic caps are securely fitted on both ends of the tube. This prevents foreign objects from entering the tube and protects the precise inner diameter edges.

4. Wrapping: Each tube is individually wrapped in heavy-duty waterproof paper or plastic film.

5. Outer Packaging: The wrapped tubes are packed in wooden crates, plywood boxes, or bundled with steel strips and woven bags, depending on the size and customer preference. For long-distance sea freight, fumigated wooden boxes are recommended for maximum protection.

A: Both are precision-finished tubes for hydraulic cylinders. Honing is a traditional abrasive process that removes material using stones; it is suitable for smaller volumes and achieves Ra≤0.4–0.8 µm. SRB is a single-pass cutting + burnishing process that is up to 20 times faster, achieves tighter tolerances (H7/H8), and smoother surfaces (Ra≤0.2–0.4 µm). SRB also creates a cold-worked surface layer with residual compressive stress, improving hardness, wear resistance, and fatigue strength. However, honing is sometimes preferred for very hard materials or when an existing bore requires correction.

A: For standard honed tubes, surface roughness (Ra) is typically 0.4–0.8 µm. For SRB (Skived & Roller Burnished) tubes, roughness can be as low as 0.2–0.4 µm, and in some cases below 0.2 µm. The characteristic cross-hatch pattern left by honing is important for oil retention and lubrication. The inner surface is also tested for hardness, with readings often taken from multiple points across the ID circumference.

A: Honed tubes are typically manufactured to ISO tolerance grades H8 or H9, with H7 available for precision applications. For example, an H8 tolerance on a 100 mm ID bore means a variation of approximately±0.054 mm, ensuring consistent and reliable piston seal fit, preventing internal leakage, and optimizing cylinder performance.

A: Most common is ST52 (DIN 2391 / E355) high-strength carbon steel for general hydraulic applications. For higher strength, ASTM A519 4140 alloy steel (yield≥785 MPa, tensile≥930 MPa) is used for high-pressure cylinders, mining, and offshore equipment. 45# (C45E) and 27SiMn (yield≥835 MPa, tensile≥1000 MPa) are also widely used per Chinese standards. Stainless steel grades (304, 316L) are available for corrosive environments or food/pharmaceutical applications.

A: With proper hydraulic system maintenance (clean oil, correct seals, no contamination), a honed tube can last 10–20 years or more. The precision surface finish reduces seal wear, extending cylinder life. Regular inspection for scoring, pitting, or wear is recommended.