A honed tube is a finished component, not a steel grade. The base metal — E355/ST52.3, CK45, 42CrMo4, 304/316L and others — is only half the specification; the other half is the bore itself. Two tubes of identical chemistry but different honing quality behave like different products on the same cylinder, because the seal runs against the bore, not against the certificate.
That distinction matters when you read a supplier's data sheet. Many pages list "honed tube" as if it were a material, then quote a single yield value. In reality the part is defined by a standard (EN 10305-1:2016 for European cold-drawn precision tube, ASTM A519 for U.S. mechanical tubing, GB/T 8713 in China), a grade, a delivery condition, and a bore specification. This guide explains what the part is, how the bore is made, and where it is used — so a purchase order can name the right thing. Request a quote with your ID × wall × Ra.
| Parameter | Capability |
|---|---|
| Product standard | EN 10305-1:2016 (cold-drawn seamless precision); ASTM A519; GB/T 8713; DIN 2391 (withdrawn → EN 10305-1) |
| Inside diameter (ID) | ≈ 40–500 mm (1.6–19.7 in); larger bores route to EN 10297-1 |
| Wall thickness | Typical 4–25 mm (0.16–0.98 in) |
| Bore tolerance | ISO H8 standard; H9 optional (e.g. 30–50 mm ID: +0.039/0 mm; 315–500 mm ID: +0.089/0 mm) |
| Surface roughness (Ra) | 0.2–0.4 µm honed; 0.05–0.2 µm SRB |
| Straightness | ≤ 0.5 mm/m (≤0.5/1000) |
| Length | Up to 12 m (39 ft), fixed or random |
| Delivery condition | +SR (BK+S, stress-relieved) for welded barrels; +N (NBK) or cold-finished available |
| Certification | EN 10204 3.1 material certificate; third-party inspection available |
| Grade | Standard / material no. | Typical +SR yield | Notes |
|---|---|---|---|
| E355 / ST 52.3 | EN 10305-1 / 1.0580 | ≥ 450 MPa (65,300 psi) | Workhorse for pressure barrels; the legacy "ST 52.3" is the same steel under DIN 2391 |
| CK45 / C45E | EN 10305-1 / 1.1191 | ≈ 340–355 MPa normalized | Heat-treatable; classic for rods, used where hardenability matters |
| SAE 1020 / 1026 | ASTM A519 | ≥ 295 MPa (42,800 psi) | General U.S. carbon tubing |
| 42CrMo4 / 4140 | EN 10305-1 / 1.7225 | high (Q+T) | Alloy, heavy-duty / high-strength barrels |
| 304 / 316L | EN 10305 / ASTM | — | Corrosion-resisting services (marine, chemical) |
These three names are not interchangeable, and mixing them on a purchase order causes the classic "arrived, but won't seal" problem.
| Attribute | Honed tube | SRB tube | DOM (un-honed) |
|---|---|---|---|
| Process | Abrasive stones, cross-hatch | Skive + roller burnish, mirror | Welded blank, cold drawn |
| Surface (Ra) | 0.2–0.4 µm | 0.05–0.2 µm | ~1.6–3.2 µm (as-drawn) |
| Oil retention | Yes (cross-hatch) | Low (mirror) | Poor |
| Surface hardness | Base metal | +30–50% (cold work) | Base metal |
| Speed / cost | Slower | Much faster on large bores | Fastest base form |
| Use as barrel | Yes | Yes (high-volume) | No — feedstock only |
The finished bore exists for one job: let a piston seal move under pressure with low friction and minimal leakage. That makes honed tubing the default barrel wherever precise, high-pressure linear motion is needed.
Beyond cylinders, the same precision bore serves as guide sleeves, spindle components and mold-ejector housings in machine tools — anywhere a sliding member needs a controlled, oil-friendly running surface.
A honed tube is a seamless steel tube whose internal bore has been precision-finished by honing or skiving & roller burnishing (SRB). The result is a controlled inside diameter (typically ISO H8, optionally H9) with a smooth, oil-retaining surface of Ra 0.2–0.4 µm, ready to receive a piston and seal without further boring. It is a finished cylinder component, not a raw steel grade.
Honed tubes are used mainly as cylinder barrels for hydraulic and pneumatic cylinders — excavators, cranes, loaders, presses, injection-molding machines, agricultural and material-handling equipment, and automation actuators. The finished bore lets the piston seal glide with low friction and minimal leakage, so it is also specified wherever precise, high-pressure linear motion is needed.
A honed tube is "tubing": its outside diameter is closely controlled and the bore is the product itself, carrying no implied pressure rating until a grade and delivery condition are specified. A pipe is sized by NPS or outside diameter plus wall thickness and is defined by a pressure-code standard (e.g. API 5L, ASTM A106). Calling a honed tube a "honed pipe" is loose trade wording and must not be used as a specification, because it omits the tolerance class and bore finish that make the part work.
The current European product standard is EN 10305-1:2016 (cold-drawn seamless precision tube). The older DIN 2391 has been withdrawn and replaced by EN 10305-1. U.S. supply follows ASTM A519 (mechanical tubing); China uses GB/T 8713 for honed cylinder tubes. For bores larger than about 320 mm ID, the supply route shifts to EN 10297-1 (machined tube), where the yield basis changes — confirm which route a supplier quotes.
Standard honed bore tolerance is ISO H8 (e.g. +0.039/0 mm at 30–50 mm ID, up to +0.089/0 mm at 315–500 mm ID); H9 is the economy alternative. Inner surface roughness is typically Ra 0.2–0.4 µm for honing and Ra 0.05–0.2 µm for SRB. Straightness is usually held at ≤0.5 mm per metre (≤0.5/1000). Note that a smoother Ra is not automatically better — below about Ra 0.1 µm the mirror finish cannot hold an oil film, which raises friction heat and accelerates seal wear.
Honing uses abrasive stones in an expanding head to cut a controlled, cross-hatched bore (Ra 0.2–0.4 µm) that retains oil in the pattern. SRB skives off a thin layer with fixed blades, then cold-work-rolls the surface to a denser, near-mirror finish (Ra 0.05–0.2 µm) and adds 30–50% surface hardness, but without the intentional oil-retaining cross-hatch. SRB is far faster on large bores; honing is preferred where tribology and straightness matter most. Many buyers accept either, provided the ID tolerance and Ra are met.
State: (1) standard and grade with the material number — e.g. EN 10305-1:2016 E355 (1.0580) or the legacy DIN 2391 ST 52.3, never the grade name alone; (2) delivery condition (+SR/BK+S for welded barrels); (3) inside diameter, wall thickness and length; (4) bore tolerance class (H8/H9); (5) surface roughness (Ra); (6) straightness; (7) end condition and any porting; (8) certificate EN 10204 3.1; (9) destination and lead-time need. Do not write only "ST52" or "355 MPa" — that leaves the supply route and yield basis undefined.
A honed tube is a finished, bore-critical component: a seamless tube whose inside has been honed or SRB-finished to ISO H8 (Ra 0.2–0.4 µm) so a piston seal can run under pressure without further machining. Its value lives in the bore — tolerance, surface texture and straightness — not in the steel name alone, and the cross-hatch that retains oil is a feature, not a flaw. Specify it by standard, grade with material number, delivery condition, ID/Wall, tolerance class and Ra, and it becomes the most reliable part of the cylinder.
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