Cold Rolled / Cold Drawn Precision Steel Tubing ST35 ST45 ST52 Welded Steel Tube

Seamless Precision Steel Tubes according to DIN2391

Standard: DIN2391 part 2 , DIN EN10305-1, DIN17175 etc;

Material: ST35,ST45,ST52.

Manufacturing method: cold-rolled / cold-drawn

Delivery condition: BK,BKS,SR,GBK,NBK.

Certificate

Factory Certification: 2.2 according to EN

Acceptance Test Certificate:3.1 according to EN 10204

Packing:

in bundles tied with steel strips. External packing by wooden cases if the wall thickness/OD ratio is low.

Oil-coating is generally necessary especially for export.

Application:
Used in hydraulic & pneumatic cylinder ,automobile and other mechanical device .Feature: high precision and high brightness, the inner and outer surface of the tubes have high cleanness without oxide, 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.

NBK means protective heat-treating under the non-oxidation environment to get a bright and smooth surface for the tubes.

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.

Chemical composition(%)

Mechanical and technological properties

Note:

• 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

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: