EN 10305 European standard for seamless cold drawn steel pipe of circular cross section used in hydraulic and pneumatic power systems.
The allowed pressure rates and temperatures are the responsibility of the customer in accordance with the state of the art and in application of the safety coefficients specified in the application regulations, codes or standards.
Tubes according to this EN 10305 European standard are characterised by having precisely defined tolerances on dimensions and a specified surface roughness.
EN 10305 seamless precision steel tube shall be manufactured from hot finished seamless tubes by cold drawning. Other suitable methods of cold working are permitted. The tubes shall be delivered in the delivery condition +N which means that after the final cold drawing operation the tubes are normalized in a controlled atmosphere.
NBK means protective heat-treating under the non-oxidation enviroment to get a bright and smooth surface for the tubes.
| Steel grade Name |
Steel Number |
C(% max) | Si(% max) | Mn(% max) | P(% max) | S(% max) |
|---|---|---|---|---|---|---|
| E215 | 1.0212 | 0.10 | 0.05 | 0.70 | 0.025 | 0.015 |
| E235 | 1.0308 | 0.17 | 0.35 | 1.20 | 0.025 | 0.015 |
| E355 | 1.0580 | 0.22 | 0.55 | 1.60 | 0.025 | 0.015 |
| Yield strength (min Mpa) |
Tensile strength (min Mpa) |
Elongation (min %) |
|---|---|---|
| 215 | 290-430 | 30 |
| 235 | 340-480 | 25 |
| 355 | 490-630 | 22 |
| Yield strength (min Mpa) |
Tensile strength (min Mpa) |
Elongation (min %) |
|---|---|---|
| Cold-finished/hard (cold-finished as-drawn) |
BK | No heat treatment after the last cold-forming process. The tubes therefore have only low deformability. |
| Cold-finished/soft (lightly cold-worked) |
BKW | After the last heat treatment there is a light finishing pass (cold drawing) With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits. |
| Annealed | GBK | After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum. |
| Normalized | NBK | The tubes are annealed above the upper transformation point in a controlled atmosphere or under vacuum. |
Note:
The tubes are supplied in the following quality grades :
Theses requirements and corresponding tests must be agreed, with the customer having to specify his requirements at the time of enquiry and on ordering.
Seamless precision tubes are used wherever a high level of measuring accuracy, smooth surfaces and improved resistance values are of the essence. These tubes are available in any desired dimension
Seamless precision tubes are used for the following applications
Standard EN 10305 covers steel-produced precision tubes. This standard includes delivery conditions for six different parts. Part 1 or as referred to as EN 10305-1 refers to Seamless cold drawn precision tubes. These precision tubes are specifically designated with the letter E, thereby the manufacturing processes adhere to the standard and keep tight tolerances, making them well suited for use as machine parts. This is because a precision steel tube en 10305-1 is identical to the system it is to be attached to.
Hence, there is no error, nor is there any wiggle room for a mismatch to occur in the system. Therefore the use of EN 10305-1 material to make a cold-drawn precision tube is a welcome one. In addition to being designated as machine steels, there are many grades with differing yield strengths that could be used in the production of EN 10305-1 equivalent tube.
Generally, most buyers prefer the use of steels that have minimum yield strength of about 235 N/mm2 or 355 N/mm2. The EN 10305-1 material is often designated with a relevant treatment the tubes have been processed with. For instance, the tube with the designation en 10305-1 E235+N would indicate that the steel is to be delivered in a normalized condition. There are several benefits of using an E355+SR EN 10305-1 Cold drawn seamless precision tube. Not only do they have a tighter level of tolerances, but they have better mechanical properties and hardness. Moreover, the cold drawing improves the surface of the EN 10305-1 E235+C tube as they are smoother.
EN 10305 is characterized by having exactly defined tolerances on dimensions and specified surface roughness. Typical fields of applications are in the furniture, vehicle, and general engineering industries. E235 in the pickled, normalized condition, to be delivered in standard length of 5.8 m.
Precision tubes according to EN10305-2 are manufactured in a cold forming process for stretch-reduced or HF-welded hollow sections (shell).
Welded drawn tubes are used primarily in the automotive industry, for instance as prop shafts, rubber/metal parts, drive shafts or cam shafts.
The application options for welded precision steel tubes according to EN 10305-2 are determined by specific technical characteristics, such as
DIN2391 ST37.4,ST52.4 bright annealed and bright normalised seamless cold drawn precision steel tubes
EN10305-1 E235 E355 Bright annealed and bright normalised seamless cold drawn precision steel tubes Weldable round precision steel tubes for hydraulic distribution systems / circuits.
Cold finished bright annealed seamless steel tubes
Cold finished bright annealed seamless precision steel tube: Cold drawn, cold rolled, precision rolled.
Finish: Annealed & pickled, bright annealed, mechanically polished & electropolished.
Ends: Tapered or plain end, square cut, burr free, plastic caps on both ends.
With years of expertise, we provide a wide range of steel tube processing services. From basic sawing and machining to complex bending and upsetting operations, we support you at every stage of your project.
Our capabilities include eccentricity reduction and concentricity improvement through turning and grinding. We specialize in creating complex geometries using rotary swaging and axial forming, and offer property modifications through partial heat treatment to meet your exact requirements.
Alloy steel pipes are widely used in high-temperature, high-pressure and corrosive service environments where conventional carbon steel pipes cannot provide sufficient mechanical strength or long-term reliability.
Manufactured from premium alloy steels containing chromium, molybdenum, nickel and other alloying elements, these pipes provide excellent resistance to heat, pressure, oxidation and corrosion, making them ideal for demanding industrial processes.
Alloy steel pipes offer superior performance under severe operating conditions. Their enhanced mechanical properties provide excellent resistance to elevated temperatures, internal pressure, corrosion and long-term creep deformation.
Alloy steel pipes are selected for critical applications where operating temperatures, pressures or corrosive media exceed the capabilities of carbon steel.
| Service Condition | Typical Application |
|---|---|
| High Temperature | Boilers, superheaters, steam headers |
| Low Temperature | Cryogenic processing systems |
| High Pressure | Power generation and process piping |
| Corrosive Media | Chemical and petrochemical plants |
| Long-Term Creep Service | Thermal power stations |
| Product Type | Common Standards |
|---|---|
| Seamless Pipes | ASTM A335 P1, P5, P9, P11, P22, P91 |
| Butt Weld Fittings | ASTM A234 WP1, WP5, WP9, WP11, WP22, WP91 |
| Forged Fittings & Flanges | ASTM A182 F1, F5, F9, F11, F22, F91 |
Sunny Steel supplies alloy steel piping products to customers worldwide across a wide range of industrial sectors. Our products are manufactured to international standards and are trusted in critical piping systems requiring long-term reliability.
Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).
| Term | Symbol | Explanation |
|---|---|---|
| Cold-finished/hard (cold-finished as-drawn) | BK | No heat treatment after the last cold-forming process. The tubes therefore have only low deformability. |
| Cold-finished/soft (lightly cold-worked) | BKW | After the last heat treatment there is a light finishing pass (cold drawing). With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits. |
| Annealed | GBK | After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum. |
| Normalized | NBK | The tubes are annealed above the upper transformation point in a controlled atmosphere or under vacuum. |
The general cold strip mills, volume should go through continuous annealing (CAPL unit) to eliminate cold hardening and rolling stress, or batch annealing reach the mechanical properties of the corresponding standard specifies. Cold rolled steel surface quality, appearance, dimensional accuracy better than hot-rolled plate, and right-rolled thin product thickness is about 0.18mm, so the majority of users favor.
Cold rolled steel coil substrate products deep processing of high value-added products. Such as electro-galvanized, hot dip galvanized, electro-galvanized fingerprint resistant, painted steel roll damping composite steel, PVC laminating steel plates, etc., so that the excellent quality of these products has a beautiful, high resistance to corrosion, has been widely used.
Cold rolled steel coil finishing after annealing, cut the head, tail, trimming, flattening, smooth, heavy volume, or longitudinal clipboard. Cold-rolled products are widely used in automobile manufacturing, household electrical appliances, instruments, switches, buildings, office furniture and other industries. Steel plate strapping package weight of 3 to 5 tons. Flat sub-volume typically 3 to 10 tons / volume. Coil diameter 6m.
Bare packing/bundle packing/crate packing/wooden protection at the both sides of tubes and suitably protected for seaworthy delivery or as requested.
