Product Description
What is a Seamless Honed Tube?
A Seamless Honed Tube is a high-quality hydraulic cylinder barrel manufactured from seamless steel tubes (no longitudinal or spiral weld seam) that undergo:
-
Cold Drawing or Hot Rolling – to achieve precise dimensions
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Internal Honing – to create a smooth, mirror-like inner surface
The absence of any weld seam is the defining characteristic. Unlike welded and drawn tubes, seamless honed tubes have uniform wall thickness, consistent material properties, and no weak points along the length.
Key Specifications
| Parameter | Value |
| Product Name | Seamless Honed Tube |
| Material | [ST52 / E355 / 45# / 20# / SAE 4140 / 27SiMn / CK45 / SAE 1026] |
| Outer Diameter (OD) | 50 – 200 mm |
| Inner Diameter (ID) | 40 – 180 mm |
| Wall Thickness | 5 – 22 mm |
| Tolerance Grade | H8 (standard) / H9 (economic) / H7 (upon request) |
| Surface Roughness (Ra) | ≤ 0.4 μm (standard) / ≤ 0.2 μm (upon request) |
| Straightness | ≤ 0.5 mm per meter |
| Length | 6 meters (standard) / 3 – 12 meters (customized) |
| No Weld Seam | 100% seamless – no longitudinal or spiral weld |
| Delivery Condition | BK+S (stress relieved) / NBK (normalized) / BK (cold drawn hard) |
| End Finish | Plastic caps + anti-rust oil |
Why Choose Seamless Honed Tubes?
| Advantage | Description |
|---|---|
| No Weld Seam Weakness | Eliminates risk of seam failure under high pressure or fatigue loading |
| Superior Pressure Rating | Can withstand higher working pressures compared to welded tubes |
| Uniform Wall Thickness | No wall thickness variation at weld zone – consistent strength |
| Excellent Fatigue Life | No weld heat-affected zone (HAZ) – better resistance to cyclic loading |
| Wider Size Range | Available in larger diameters and thicker walls than welded tubes |
| Full Traceability | Heat number traceable from raw material to finished tube |
Seamless vs. Welded Comparison
| Feature | Seamless Honed Tube | Welded & Drawn (DIN 2393) |
|---|---|---|
| Weld seam | None – 100% seamless | Longitudinal weld seam present |
| Maximum working pressure | Higher (up to 500 bar) | Lower (limited by weld integrity) |
| Fatigue resistance | Excellent | Moderate (weakest at weld) |
| Wall thickness uniformity | Consistent full circumference | Slight variation at weld zone |
| Size range | ID up to 800mm+ | ID typically ≤ 150mm |
| Material grades | Wide range including alloys | Limited to lower carbon grades |
| Cost | Higher | Lower |
| Typical application | High-pressure, heavy-duty, safety-critical | Light to medium duty, cost-sensitive |
For critical applications involving high pressure, shock loading, or safety requirements, seamless is the preferred choice.
Available Materials & Standards
| Material Grade | Standard | Key Properties | Typical Application |
|---|---|---|---|
| ST52 / E355 | DIN 2391 / EN 10305-1 | High strength, excellent toughness | Most common seamless cylinder tube |
| 45# / CK45 | GB/T 8713 / DIN 2391 | Medium carbon, wear resistant | Heavy-duty industrial cylinders |
| SAE 4140 | ASTM A519 | Cr-Mo alloy, ultra-high strength | High-pressure, high-temperature |
| 27SiMn | GB/T 17396 | Manganese-silicon alloy | Mining, construction equipment |
| 20# / SAE 1020 | GB/T 8162 / ASTM A519 | Low carbon, good weldability | Welded end connections |
| SAE 1026 | ASTM A519 | Higher carbon than 1020 | General hydraulic cylinders |
| E355 | EN 10305-1 | Fine grain, superior toughness | Dynamic load applications |
| Q355B | GB/T 1591 | Chinese standard equivalent to ST52 | Cost-effective alternative |
Standard Size Range
Below is our common size range for seamless honed tubes. Custom sizes available upon request.
| ID (mm) | OD (mm) | Wall Thickness (mm) | Max Working Pressure (bar)* |
|---|---|---|---|
| 40 | 50 – 55 | 5.0 – 7.5 | 350 – 420 |
| 50 | 60 – 65 | 5.0 – 7.5 | 350 – 420 |
| 63 | 73 – 80 | 5.0 – 8.5 | 300 – 400 |
| 80 | 90 – 100 | 5.0 – 10.0 | 280 – 400 |
| 100 | 115 – 125 | 7.5 – 12.5 | 280 – 420 |
| 125 | 140 – 152 | 7.5 – 13.5 | 280 – 420 |
| 140 | 156 – 168 | 8.0 – 14.0 | 250 – 400 |
| 160 | 180 – 190 | 10.0 – 15.0 | 250 – 380 |
| 180 | 200 – 220 | 10.0 – 20.0 | 250 – 450 |
| 200 | 220 – 245 | 10.0 – 22.5 | 230 – 450 |
| 220 | 250 – 273 | 15.0 – 26.5 | 280 – 480 |
| 250 | 280 – 325 | 15.0 – 37.5 | 250 – 500 |
Maximum working pressure is approximate, based on ST52 material with 4:1 safety factor. Actual depends on material, tolerance, and application.
Custom Sizes: ID from 30mm to 800mm, any OD/WT combination available. Minimum order quantity may apply.
Technical Features
| Feature | Value / Description |
|---|---|
| Manufacturing method | Hot rolled seamless + cold drawn + honed |
| Honing method | Fixed multi-stone honing head |
| Surface roughness (Ra) | 0.2μm – 0.8μm |
| ID tolerance | H7, H8, H9 (ISO 286-2) |
| Roundness | ≤ 50% of ID tolerance |
| Wall thickness tolerance | ±5% – ±10% (depending on standard) |
| Straightness | ≤ 0.5mm per meter, ≤ 0.8mm per 3 meters |
| Hardness (BK+S) | 180 – 240 HB (ST52) / 200 – 280 HB (4140) |
| Tensile strength (ST52) | 520 – 680 MPa |
| Yield strength (ST52) | ≥ 420 MPa |
| Elongation (ST52) | ≥ 20% |
| Maximum working pressure | Up to 500 bar (depending on dimensions) |
Quality Assurance
Raw Material Control
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Mill Test Certificate (MTC) from steel mill
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Chemical composition verified per heat number
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Mechanical properties tested per batch
In-Process Inspection
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Dimensional checks after cold drawing
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UT/ECT for surface defects (optional)
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Hardness testing after heat treatment
Final Inspection (100%)
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ID measurement – Air gauge or electronic plug gauge
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Surface roughness – Profilometer
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Visual inspection – Borescope for internal surface
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Straightness – Laser or straight edge
Documentation Provided
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✅ EN 10204 3.1 – Material certificate with batch traceability
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✅ COA (Certificate of Analysis) – Full chemical & mechanical properties
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✅ Inspection Report – ID, tolerance, roundness, straightness, Ra
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✅ Hydrostatic test report (if applicable)
Certifications
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✅ ISO 9001:2015 – Quality management
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✅ Third-party inspection (SGS / BV / TUV / DNV) available
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✅ ABS / LR / DNV marine certification available upon request
Pressure Rating Reference (ST52 Material)
| ID (mm) | Wall Thickness (mm) | Working Pressure (bar)* | Burst Pressure (bar)* |
|---|---|---|---|
| 50 | 5.0 | 320 | 1280 |
| 50 | 7.5 | 450 | 1800 |
| 80 | 6.0 | 250 | 1000 |
| 80 | 10.0 | 380 | 1520 |
| 100 | 7.5 | 250 | 1000 |
| 100 | 12.5 | 380 | 1520 |
| 125 | 8.0 | 220 | 880 |
| 125 | 13.5 | 340 | 1360 |
| 160 | 10.0 | 210 | 840 |
| 160 | 15.0 | 290 | 1160 |
Calculated with safety factor 4:1, using ST52 yield strength ≥420MPa. For actual design, please consult engineering standards.
Packing & Delivery
| Packing Method | Description |
|---|---|
| Rust protection | Anti-rust oil (inside + outside) |
| End protection | Heavy-duty plastic caps (both ends) |
| Interleaving | Kraft paper between tube layers |
| Bundling | Steel straps with edge protectors, 500 – 2000 kg per bundle |
| Outer packing | Waterproof woven fabric + moisture barrier |
| Optional premium packing | Individual PVC sleeve + plywood crates |
| Container loading | 20ft GP / 40ft HC / 40ft OT (open top for long lengths) |
Delivery Time:
-
Stock sizes (common IDs): 7 – 15 days
-
Custom sizes: 20 – 35 days
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Large quantities (>100 tons): 30 – 45 days
Incoterms: EXW, FOB, CIF, CFR, DDP – flexible
Why Choose Our Seamless Honed Tubes
| Reason | Detail |
|---|---|
| True seamless | 100% seamless – no weld seam risk |
| Large size capability | ID up to 800mm, wall up to 50mm |
| Wide material range | Carbon, alloy, and stainless steel available |
| Strict QC | 100% dimensional inspection before shipment |
| Competitive pricing | Direct from manufacturer |
| Short lead time | Large inventory of raw seamless tubes |
| Global shipping | Exported to 50+ countries |
| Technical support | Engineering team for pressure rating and material selection |
Typical Applications
| Industry | Application | Recommended Material |
|---|---|---|
| Hydraulic Cylinders | Heavy-duty, telescopic, tie-rod cylinders | ST52 / E355 |
| Construction Equipment | Excavators, loaders, bulldozers, backhoes | 27SiMn / ST52 |
| Mining Equipment | Dump truck cylinders, roof supports | 27SiMn / SAE 4140 |
| Marine & Offshore | Steering gear, hatch covers, deck machinery | ST52 (with coating) / SS316 |
| Agricultural Machinery | Tractor cylinders, harvesters | 45# / ST52 |
| Material Handling | Forklift mast, scissor lifts, cranes | ST52 / E355 |
| Presses & Machine Tools | Hydraulic presses, injection molding machines | SAE 4140 / ST52 |
| Oil & Gas | Wellhead equipment, blowout preventers | SAE 4140 / L80 |
| Wind Energy | Pitch and yaw cylinders | ST52 / E355 (low temp) |
| Railway | Brake cylinders, suspension components | E355 |
Technical Data Sheet (Reference)
*For ST52 / E355 material, H8 tolerance, BK+S condition, 6m length:*
| ID (mm) | OD (mm) | WT (mm) | Weight (kg/m) | ID Tolerance H8 (μm) | Ra (μm) |
|---|---|---|---|---|---|
| 40 | 50 | 5.0 | 5.55 | +39 / 0 | ≤ 0.4 |
| 50 | 60 | 5.0 | 6.78 | +39 / 0 | ≤ 0.4 |
| 63 | 76 | 6.5 | 11.14 | +46 / 0 | ≤ 0.4 |
| 80 | 95 | 7.5 | 16.18 | +46 / 0 | ≤ 0.4 |
| 100 | 114 | 7.0 | 18.47 | +54 / 0 | ≤ 0.4 |
| 125 | 140 | 7.5 | 24.51 | +54 / 0 | ≤ 0.4 |
| 140 | 159 | 9.5 | 35.01 | +63 / 0 | ≤ 0.4 |
| 160 | 180 | 10.0 | 41.92 | +63 / 0 | ≤ 0.4 |
| 180 | 203 | 11.5 | 54.31 | +72 / 0 | ≤ 0.4 |
| 200 | 219 | 9.5 | 49.07 | +72 / 0 | ≤ 0.4 |
Full technical data sheet available upon request for all sizes and materials.
Main Applications
- Hydraulic & Pneumatic: Hydraulic cylinder barrels, air cylinders, power unit pipes
- Construction Machinery: Excavators, loaders, cranes, road rollers
- Automotive & Rail: Shock absorber cylinders, steering cylinders
- Petrochemical: High-pressure fluid pipes, anti-corrosion honed pipelines
- Precision Machinery: CNC machine tool shafts, injection molding machine parts
- Energy Equipment: Wind turbine cylinders, hydraulic support columns
Why Choose Us?
- Factory Direct Sales with large stock and competitive prices.
- Full Inspection: chemical composition, mechanical properties, size, roughness, straightness tested piece by piece.
- Fast Customization: accept drawings for special size, length, material and surface treatment (chrome plating, roller burnishing).
- Quick Delivery: stock items ship in 48 hours; custom orders 7–15 days.
- Technical Support for material selection and application matching.
FAQ
Q: What is the difference between honed tube, seamless pipe and burnished tube?
A: Honed tube has higher precision and better roundness, ideal for long-term seal friction – the best choice for hydraulic cylinders.
Q: How to choose material?
A: Low pressure: 20# / 45#; Medium-high pressure: 40Cr / 27SiMn; Corrosive environment: 304 / 316.
Q: Do you supply samples and small orders?
A: Yes, we support sample orders, small-batch trials and cut-to-length service.
