|Place of Origin:||China|
|Minimum Order Quantity:||1 metric ton|
|Packaging Details:||Wooden case|
|Delivery Time:||15 days|
|Payment Terms:||L/C, T/T|
|Supply Ability:||5000 metric tons per month|
Standard: DIN2391 part 2 , DIN EN10305-1, DIN17175 etc;
Manufacturing method: cold-rolled / cold-drawn
Delivery condition: BK,BKS,SR,GBK,NBK.
Factory Certification: 2.2 according to EN
Acceptance Test Certificate:3.1 according to EN 10204
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.
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.
|Material number||Mfg. Process||C
|Code number||Material number||Cold-finished hard(BK)||Cold-finished/soft (BKW) 3)|
|Code number||Cold finished (soft)(BKW)||Annealed (GBK)||Normalized (NBK)|
|Rm(Mpa)||ReH (Mpa)||A(%)||Rm(Mpa)||A(%)||Rm (Mpa)||ReH (Mpa)||A(%)|
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.
|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.|