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EN 10305 seamless precision steel tube

Date:2019-08-30    View:1005      Tag:EN 10305 seamless precision steel tube

EN10305-1, E235+N Seamless tube

Applicastion for power steering

EN 10305 european standard specifies the technical delivery conditions for seamless cold drawn steel pipe of circular cross section used in hyhydraulic 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 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. 

Seamless cold drawn precision steel tubes in acc. EN 10305 1

Chemical composition(%) of EN 10305-1

Steel grade
 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)
(min %)
 215  290-430  30
 235  340-480  25
 355  490-630  22

EN 10305-4 Tubes for hydraulic and pneumatic power systems

The pipes are used to manufacture hydraulic and pneumatic power systems of the I generation and they are also used in the pipelines of hydraulic and pneumatic systems. They are manufactured as seamless cold drawn tubes. They are provided in the +N delivery condition (normalized in a controlled atmosphere).

Chemical composition

Steel grade % of mass
Symbol C max. Si max. Mn max. P max S max Al total. Max
E215 0,10 0,05 0,70 0,025 0,015 0,025
E235 0,17 0,35 1,20 0,025 0,015 -
E355 0,22 0,55 1,60 0,025 0,015 -

Mechanical properties in room temperature

Steel grade Yield limit ReH Min. MPa Tensile strength Rm Min MPa Elongation A Min %
E215 215 290 to 430 30
E235 235 235 to 480 25
E355 355 490 to 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 :

  1. precision steel tubes intended primarily for mechanical stressing, without any particular quality requirement and without acceptance test certificate.
  2. precision steel tubes intended primarily for mechanical stressing, with special quirement and exclusively with acceptance test certificate.
  3. 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.
Condition on delivery of EN 10305:
Term Symbol Explanation
(cold-finished as-drawn)
BK No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
(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.
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