Product Description
What is a Precision Honed Tube?
A Precision Honed Tube is a high-end seamless steel tube manufactured through a specialized process combining:
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Cold Drawing or Cold Rolling – for precise outer diameter and improved mechanical properties
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Multi-stage Internal Honing – using fixed abrasive stones to achieve exceptional inner surface finish and dimensional accuracy
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Stress Relieving – to eliminate residual stresses from cold working
The result is a tube with extremely tight tolerances (H7/H8) and a mirror-like inner surface (Ra ≤ 0.3μm) , making it the preferred raw material for precision hydraulic cylinders, servo cylinders, and high-performance pneumatic systems.
Compared with standard honed tubes, precision honed tubes have stricter tolerance control and are widely used in servo hydraulic systems, precision machinery, medical equipment, and new energy equipment.
Key Specifications
| Parameter | Value |
|---|---|
| Product Name | Precision Honed Tube |
| Model | [PHT-XXXX-XX] |
| Material | [ST52 / E355 / CK45 / 45# / 20# / SAE 1020 / SAE 4140] |
| Outer Diameter (OD) | [e.g., 40 – 160 mm] |
| Inner Diameter (ID) | [e.g., 30 – 140 mm] |
| Wall Thickness | [e.g., 5 – 18 mm] |
| Tolerance Grade | H7 (ultra precision) / H8 (high precision – standard) / H9 (commercial precision) |
| Surface Roughness (Ra) | ≤ 0.3 μm for H7 / ≤ 0.4 μm for H8 / ≤ 0.8 μm for H9 |
| Roundness Tolerance | ≤ 40% of ID tolerance |
| Straightness | ≤ 0.3 mm per meter (H7) / ≤ 0.5 mm per meter (H8/H9) |
| Length | 6 meters (standard) / 3 – 12 meters (customized) |
| Delivery Condition | BK+S (stress relieved) / NBK (normalized) / GBK (annealed) |
| End Finish | Plastic caps + anti-rust oil |
Why Choose Precision Honed Tubes?
| Advantage | Description |
|---|---|
| Ultra-tight Dimensional Accuracy | H7/H8 tolerance ensures perfect piston-to-barrel fit, minimizing internal leakage |
| Superior Surface Finish | Ra ≤ 0.3μm dramatically reduces seal wear and friction |
| Extended Cylinder Life | Smooth surface prevents micro-leaks and reduces maintenance frequency |
| Consistent Quality | Batch-to-batch consistency guaranteed through statistical process control |
| Excellent Straightness | ≤ 0.3mm/m ensures smooth piston travel without binding |
| Full Traceability | Each tube marked with heat number; EN 10204 3.1 certificate provided |
Tolerance Grade Comparison
| Grade | ID Tolerance (μm) | Ra (μm) | Typical Application | Price Level |
|---|---|---|---|---|
| H7 | ≤ 25 – 35 | ≤ 0.3 | Servo cylinders, aerospace, precision machine tools | High |
| H8 | ≤ 40 – 60 | ≤ 0.4 | General hydraulic cylinders, industrial machinery | Medium |
| H9 | ≤ 60 – 100 | ≤ 0.8 | Agricultural equipment, low-speed cylinders | Economic |
Note: Tolerance values vary slightly with diameter. Contact us for specific tolerance charts.
Available Materials & Standards
| Material Grade | Standard | Key Properties | Typical Application |
|---|---|---|---|
| ST52 / E355 | DIN 2391 / EN 10305-1 | High strength, good weldability | Most popular for precision cylinders |
| CK45 / 45# | DIN 2391 / GB/T 8713 | Medium carbon, wear resistant | Heavy-duty industrial cylinders |
| 20# / SAE 1020 | GB/T 8162 / ASTM A519 | Low carbon, excellent formability | Formed end cylinders, welded assemblies |
| SAE 4140 | ASTM A519 | Chromium-molybdenum alloy, high strength | High-pressure, heavy-load applications |
| 27SiMn | GB/T 17396 | Manganese-silicon alloy | Mining and construction equipment |
| E355 | EN 10305-1 | Fine grain steel, superior toughness | Dynamic load cylinders |
Standard Size Range
Below is our common size range for precision honed tubes. Custom sizes available upon request.
| ID (mm) | OD (mm) | Wall Thickness (mm) | Typical Tolerance |
|---|---|---|---|
| 30 | 38 – 45 | 4.0 – 7.5 | H8 / H7 |
| 40 | 50 – 55 | 5.0 – 7.5 | H8 / H7 |
| 50 | 60 – 65 | 5.0 – 7.5 | H8 / H7 |
| 63 | 73 – 80 | 5.0 – 8.5 | H8 / H7 |
| 80 | 90 – 100 | 5.0 – 10.0 | H8 / H7 |
| 100 | 115 – 125 | 7.5 – 12.5 | H8 |
| 125 | 140 – 152 | 7.5 – 13.5 | H8 |
| 140 | 156 – 168 | 8.0 – 14.0 | H8 |
| 160 | 180 – 190 | 10.0 – 15.0 | H8 |
Custom Sizes: ID from 20mm to 400mm, any OD/WT combination. H7 tolerance available for most sizes.
Technical Features
| Feature | Value / Description |
|---|---|
| Honing method | Fixed multi-stone honing head with automatic sizing |
| Surface roughness achievable | Ra 0.2μm – 0.8μm (H7 achievable: Ra ≤ 0.3μm) |
| ID tolerance capability | H7, H8, H9 (ISO 286-2) |
| Roundness deviation | ≤ 50% of ID tolerance (H7: ≤ 40%) |
| Cylindricity | ≤ 50% of ID tolerance per 300mm length |
| Hardness (BK+S) | 180 – 240 HB (depending on material) |
| Microstructure | Fine pearlite + ferrite, stress relieved |
| Maximum working pressure | Up to 500 bar (depending on wall thickness and material) |
| Chrome plating ready | Yes – honed surface ideal for hard chrome plating |
| Seal compatibility | Compatible with all standard hydraulic seals (NBR, FKM, PTFE, PU) |
Quality Assurance
Dimensional Inspection
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ID measurement: Air gauge or electronic plug gauge (accuracy ±0.001mm)
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OD measurement: Laser micrometer
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Roundness: Roundness tester
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Surface roughness: Profilometer (Ra, Rz, Rmax)
Non-Destructive Testing (NDT)
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Eddy current testing (ECT) available
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Ultrasonic testing (UT) available upon request
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Hydrostatic testing available
Documentation Provided
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✅ EN 10204 3.1 – Material certificate with batch traceability
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✅ COA (Certificate of Analysis) – Chemical composition + mechanical properties
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✅ Inspection Report – ID, tolerance, roundness, straightness, surface roughness
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✅ Mill Test Certificate (MTC)
Certifications
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✅ ISO 9001:2015 – Quality management system
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✅ IATF 16949 (upon request) – Automotive grade
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✅ Third-party inspection (SGS / BV / TUV) available
Packing & Delivery
| Packing Method | Description |
|---|---|
| Surface protection | Anti-rust oil (inside + outside) + VCI paper |
| End protection | Heavy-duty plastic caps on both ends |
| Interleaving | Kraft paper between layers |
| Bundling | Steel straps, 500 – 1500 kg per bundle |
| Outer packing | Waterproof woven fabric + plywood crates (for H7 premium products) |
| Container loading | 20ft GP / 40ft HC – loading plan provided |
Delivery Time:
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Stock sizes: 7 – 15 days
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Custom sizes (H8): 20 – 30 days
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Custom sizes (H7): 25 – 40 days
Incoterms: EXW, FOB, CIF, CFR, DDP – flexible
Why Choose Our Precision Honed Tubes
| Reason | Detail |
|---|---|
| Dedicated honing workshop | 15+ honing machines, capacity 3000 tons/year |
| Strict tolerance control | Cpk ≥ 1.33 for all H7/H8 dimensions |
| 100% inspection | Every tube inspected before shipment |
| Short lead time | Large stock of cold drawn blanks |
| Competitive pricing | Factory direct – no middleman markup |
| Technical support | Engineering team advises on tolerance selection |
| Global export experience | Shipped to 30+ countries |
Typical Applications
| Industry | Application | Recommended Grade/Tolerance |
|---|---|---|
| Machine Tools | Hydraulic cylinders for presses, injection molding machines | H7, ST52 |
| Material Handling | Forklift mast cylinders, scissor lifts | H8, ST52/E355 |
| Construction Equipment | Excavator, loader, bulldozer cylinders | H8, 27SiMn/ST52 |
| Agricultural Machinery | Tractor 3-point hitch cylinders | H9, 45#/ST52 |
| Automotive | Tilt cylinders, suspension components | H8, SAE 1020 |
| Aerospace | Landing gear, flight control actuators | H7, 4140/E355 |
| Marine | Steering cylinders, hatch covers | H8, SS316/Duplex (stainless) |
| Industrial Automation | Pneumatic cylinders, servo actuators | H7, ST52 |
Technical Data Sheet (Reference)
*For ST52 / E355 material, H8 tolerance, BK+S condition:*
| ID (mm) | ID Tolerance H8 (μm) | Ra (μm) | Roundness (μm) | Straightness (mm/m) |
|---|---|---|---|---|
| 40 | +39 / 0 | ≤ 0.4 | ≤ 20 | ≤ 0.5 |
| 50 | +39 / 0 | ≤ 0.4 | ≤ 20 | ≤ 0.5 |
| 63 | +46 / 0 | ≤ 0.4 | ≤ 23 | ≤ 0.5 |
| 80 | +46 / 0 | ≤ 0.4 | ≤ 23 | ≤ 0.5 |
| 100 | +54 / 0 | ≤ 0.4 | ≤ 27 | ≤ 0.5 |
| 125 | +54 / 0 | ≤ 0.4 | ≤ 27 | ≤ 0.5 |
Full technical data sheet available upon request.
- Servo Hydraulic Actuators: Used in industrial robots and automated production lines, high positioning accuracy and fast response.
- CNC Machine Tools: Applied in spindle sleeves and guide sleeves, ensuring stable operation and high machining accuracy.
- Medical Equipment: Used in operating tables and diagnostic equipment, quiet, smooth, and jitter-free.
- New Energy Lithium Battery Equipment: Precision cylinders for electrode slicers and filling machines, wear-resistant and pollution-free.
- Airport Ground Support Equipment: Used in boarding bridges and aircraft maintenance lifts, high reliability and long service life.
