Honed Hydraulic Cylinder Tubing Precision Cold Drawn Seamless Tube with ISO H8/H9 ID Tolerance and Ra max 0.40 μm for Automotive Applications
Honed Hydraulic Cylinder Tubing — Precision Cold-Drawn Seamless Tube for Automotive
Material
Honed hydraulic cylinder tubing is a precision cold-drawn seamless steel tube whose inside diameter (ID) is honed or skived & roller burnished (SRB) to achieve tight dimensional tolerances and a very smooth bore—critical for hydraulic cylinders where sealing performance, friction, and service life depend heavily on ID quality.
Typical steel families include EN precision grades (E235 / E355), DIN precision grades (St52), and ASTM mechanical tubing grades (SAE 1020 / 1025), selected based on required strength, machinability, and fatigue performance.
Specifications
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Base tube process: Seamless, cold-finished / cold-drawn mechanical or precision tubing; stress relief and sizing per order.
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Inside processing: Honed or skived & roller burnished, commonly to ISO H8 / H9 ID tolerance.
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Typical size window : OD Ø50–245 mm, ID Ø40–200 mm (other sizes by agreement).
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Surface roughness (ID):
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SRB: Ra max 0.30 μm
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Honed: Ra max 0.40 μm
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Straightness (example guidance): local deviation max 1 mm / 1000 mm.
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Length supply: mill/random lengths or cut-to-length (common hydraulic tube programs include ~5–8 m).
Key Features
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Ready-to-machine / ready-to-assemble bore: ISO H8/H9 ID tolerance and controlled Ra reduce seal wear and minimize leakage risk.
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Optimized cylinder performance: Honing can create a cross-grinding pattern; combined with low roughness, it helps reduce friction effects and extend component life.
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Automotive-grade consistency: Seamless construction and controlled chemistry/mechanics support repeatable machining and stable performance in motion-control components.
Our Advantages
1) “What ID tolerance and Ra can you actually deliver for cylinder bores?”
We supply honed/SRB tubing commonly to ISO H8 or H9 ID tolerance with Ra up to 0.40 μm (honed) or Ra up to 0.30 μm (SRB), matching typical cylinder-tube technical sheets used in the market.
2) “How do you control the inside surface to avoid scoring, pits, and seal damage?”
Inside surface quality is treated as a critical-to-function requirement. ASTM A519 describes an optional requirement for tubing where the inside surface is of prime importance and no stock removal is intended, noting that special processing/selection may be needed to meet the required surface. We align our inspection plan accordingly (bore visual checks, roughness verification, dimensional gauging; and NDT can be agreed when required).
3) “Can you provide traceability, certificates, and shipping protection for long-distance supply?”
We support full traceability with heat/lot documentation and can provide EN 10204 3.1 / 3.2 certificates when specified. Packaging and storage guidance is treated as part of delivery quality (dry covered storage, careful lifting/handling, and protection of finished surfaces).
Chemical Composition
| Grade | Standard reference | C (%) | Si (%) | Mn (%) | P (%) | S (%) |
|---|---|---|---|---|---|---|
| E235 | EN 10305-1 | ≤0.17 | ≤0.35 | ≤1.20 | ≤0.025 | ≤0.025 |
| E355 | EN 10305-1 | ≤0.22 | ≤0.55 | ≤1.60 | ≤0.025 | ≤0.025 |
| St52 | DIN 2391 | ≤0.22 | ≤0.55 | ≤1.60 | ≤0.025 | ≤0.025 |
| 1020 | ASTM A519 | 0.18–0.23 | — | 0.30–0.60 | ≤0.040 | ≤0.050 |
| 1025 | ASTM A519 | 0.22–0.28 | — | 0.30–0.60 | ≤0.040 | ≤0.050 |
Mechanical Properties
| Grade | Typical delivery condition | Yield strength (MPa) | Tensile strength (MPa) | Elongation (%) |
|---|---|---|---|---|
| E235 | +SR (stress relieved) | ≥350 | ≥420 | ≥16 |
| E355 | +SR (stress relieved) | ≥450 | ≥580 | ≥10 |
| St52 | BK+S / +SR (stress relieved) | ≥420 | 580–740 | ≥10 |
| 1020 | Stress relieved (SR), typical | ~345 (50 ksi) | ~448 (65 ksi) | ~10 |
| 1025 | Stress relieved (SR), typical | ~483 (70 ksi) | ~586 (85 ksi) | ~10 |
Standards & Compliance
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ASTM: ASTM A519/A519M — Seamless carbon/alloy steel mechanical tubing (hot-finished or cold-finished).
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EN: EN 10305-1 (seamless cold-drawn precision tubes), commonly used for E235/E355 cylinder tubes.
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DIN: DIN 2391 — Seamless precision steel tubes (St52 commonly referenced in the cylinder-tube market).
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GOST: GOST 8734 / GOST 8733 — Seamless cold-formed/drawn tubes and technical requirements (commonly referenced for CIS markets).
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JIS: JIS G3445 — Carbon steel tubes for machine structural purposes (common in machinery/automotive supply chains).
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GB: GB/T 3639 — Cold drawn/cold rolled precision seamless steel tubes (widely used for mechanical, hydraulic, and auto parts).
Application Areas
Main sectors: hydraulic & pneumatic cylinders, precision machinery, automotive components, and industrial motion control.
Where it is used (examples):
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Automotive & commercial vehicles: hydraulic cylinder barrels for lifting/tipping systems, service equipment cylinders, and actuator sleeves where a high-quality ID is needed.
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Automotive manufacturing equipment: hydraulic cylinders in stamping lines, clamping systems, and test rigs—benefiting from H8/H9 bores and controlled Ra.
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General hydraulics: cylinder barrels for presses, material handling, and heavy-duty actuators (honed or SRB).
Q: Are you trading company or manufacturer ?
A: manufacturer,also can do trading.
Q: How long is your delivery time?
A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock,
it is according to quantity.
Q: Do you provide samples? is it free or extra ?
A: Yes, we could offer the sample for free charge but need pay the cost of freight.
Q: What is your terms of payment ?
A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.
If you have another question, pls feel free to contact with me.
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