EN 10305-1 is the European Standard applications for specifies steel tubes. The technical delivery conditions for seamless cold drawn steel tubes of circular cross section for precision applications with specified outside diameter D <= 380 mm. NOTE This document may also be applied to other types of cross section and other suitable processes. Tubes according to this document are characterized by having precisely defined tolerances on dimensions and a specified maximum surface roughness.
Typical fields of application are in the automotive, furniture and general engineering industries.
Steel tubes for precision applications – Technical delivery conditions – Part 1: Seamless cold drawn tubes.
Seamless Precision Steel Tubes according to EN 10305-1
Standard and Steel grade:
- EN10305-1 E215/E235/E355
- high precision and high brightness, the inner and outer surface of the tubes have high cleanness without oxid
- mechanical properties of the final tubes also come out excellent
- promising no leakage under high pressure
- no deformation after cold-bent and no cracks when flaring and flattening
- ensuring the efficient operation in all service.
DIN 2391-81 Part 2 Seamless Precision steel tubes(DIN2391-81)
Standard DIN 2391 defines the technical delivery conditions for seamless precision steel tubes according to DIN 2391 Part 1 which are made from the steel grades listed in section 5.
Tubes according to this Standard are mainly used where accuracy to dimension and, possibly, small wall thicknesses and good surface condition are required.
Table1, Chemical composition(%) (cast analysis)a
|Steel grade||% by mass|
a Elements not included in this table(but see footnote c) shall not be intentionally added to the steel without the agreement of the purchaser, except for elements which may be added for finishing the cast. All appropriate measures shall be taknen to prevent the additon of undesirable elementts from scrap or other materials used inthe steel making process.
b For the steel grades E235 and E355 a controlled sulphur content of 0.015% to 0.040% is specified to support machinability. It shall be obtained by result phursing the steel after maximum desulphurisation or alternatively by using a low oxygen process.
c Additions of Nb, Ti and V are permitted at the discretion of the manufacturer. The content of these elements shalll be reported.
Permissible deviations of the product analysis from the specified limits on cast analysisi given Table1
|Element||Limiting value for cast analysis in accordance with Table 1 in % by mass||Permissible deviation of the roduct analysisi in % by mass.|
Mechanical properties at room temperature
|Rm /MPa||A%||Rm /MPa||A%|
|Rm /MPa||ReH /MPa||A%||Rm /MPa||A%||Rm /MPa||ReH /MPa||A%|
Diameter tolerances for heat treated tubes
The tubes are supplied in the following quality grades :
A) precision steel tubes intended primarily for mechanical stressing, without any particular quality requirement and without acceptance test certificate.
B) precision steel tubes intended primarily for mechanical stressing, with special quirement and exclusively with acceptance test certificate.
C) 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:
|BK||No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.|
|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.|
|View the PDF catalogue of EN 10305-1, Seamless precision steel tubes|