EN 10305 european standard specifies the technical delivery conditions for seamless cold drawn steel pipe of circular cross section used in hydraulic and pneumatic power systems.
Standard and Steel grade:
- EN10305-1 E215
- EN10305-1 E235
- EN10305-1 E355
The allowed pressure rates and temperatures are the responsibility of the customer in accordance with the state of the art and in the application of the safety coefficients specified in the applicable 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 drawing. 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 environment to get a bright and smooth surface for the tubes.
BS EN 10305 Steel tubes for precision applications. Technical delivery conditions, consists of the following parts:
- Part 1: Seamless cold drawn tubes
- Part 2: Welded cold drawn tubes
- Part 3: Welded cold sized tubes
- Part 4: Seamless cold drawn tubes for hydraulic and pneumatic power systems
- Part 5: Welded cold sized square and rectangular tubes
- Part 6: Welded cold drawn tubes for hydraulic and pneumatic power system
Chemical composition(%) of EN 10305-1
| Steel grade | 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 |
Mechanical and technological properties of EN 10305-1
| Yield strength (min Mpa) | Tensile strength (min Mpa) | Elongation (min %) |
|---|---|---|
| 215 | 290-430 | 30 |
| 235 | 340-480 | 25 |
| 355 | 490-630 | 22 |
Inspection and test list
| Inspection and test type | Inspection and test frequency | |
|---|---|---|
| Internal tests | Acceptance tests | |
| Chemical analysis | M | M |
| Tensile testing | M | One pipe per every tested batch |
| Flattening test or expansion test | M | 2 per every tested batch |
| Dimension verification | M | M |
| Visual inspection | M | M |
The yield point for the annealed (GBK)condition on delivery is at least 50% of the (ultimate) tensile strength. Depending upon the degree of deformation in the drawing operation, the yield point of tubes delivered in the cold-finished/hard (BK)and cold-finished/soft(BKW) conditions, may be increased to a level close to the tensile strength.
In calculating the yield point, the following values are recommended : cold-finished/hard condition on delivery ≥ 80% of the tensile strength, cold-finished/soft condition on delivery ≥ 70% of the tensile strength.
Quality grade of EN 10305-1
The tubes are supplied in the following quality grades :
- Precision steel tubes intended primarily for mechanical stressing, without any particular quality requirement and without acceptance test certificate.
- Precision steel tubes intended primarily for mechanical stressing, with special quirement and exclusively with acceptance test certificate.
- Precision steel tubes with special requirement according to section 12. 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 steel pipe conditions on delivery
| 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. |
