Views: 11 Author: Site Editor Publish Time: 2017-12-01 Origin: Site
DIN 2391 is one of the primary standards in steel pipe industry and it contains some requirements such as specification, application, mechanical properties, tolerance and so on. This standard stressed some details from production to delivery of seamless precision steel pipe.
This standard stipulates all pipes should be produced with electric steel or basic oxygen steel. And the steel should be cast as killed steel. Our company purchases raw steel from the well-known company, such as Zenith Steel Group and Huaigang Special Steel. So you can trust our seamless tubes with the high-quality raw material.
The material you can choose:
10#(St37.4, St35, St37, E235)
20#(St45, St44, E255)
and other special material
2. Mechanical properties:
The common mechanical properties mainly include tension strength, yield strength and elongation. And the common delivery conditions include BK, BKW, BKS, GBK, NBK. All our seamless steel tubes can meet customer requirements in mechanical properties and we can also provide related test reports.
|Cold finished (hard)||BK||There is no heat treating following the final cold processing. And also have a high drag to shape change|
|Cold finished （soft）||BKW||Heat treatment is allowed, so it can undergo some shape change（bengding and expanding）|
|Cold finished and stress-relieved||BKS||After last cold forming process to heat treatment, makes the tubes can enable forming and machining.|
|Annealed||GBK||Makes the tubes anneal in a controlled atmosphere.|
|Normalized||NBK||The last cold forming is followed by annealing above the upper transformation point in a controlled atmosphere|
We can reach higher precision than DIN2391 standard requirements.
Cold drawn tubes: +/-0.1mm
Cold Rolled tubes: +/0.05mm
The standard stipulates that cut length should meet tolerance of +/- 500mm of the length ordered. But we can control the tolerance within +/- 50mm.
With so high precision, our seamless steel tubes can be used in most hydraulic system, auto area, and in the occasion where high precision, brightness, cleanness and mechanical properties are required.
Common application: gas spring, shock absorber, cylinder, heat exchanger and so on.
5. How to calculate the weight of steel pipe?
The formula is （OD-WT）* WT *0.02466 * L
OD: Outer Diameter
WT: Wall Thickness
Above is a brief introduction and our factory Changzhou Raymond Steel Tube Co., Ltd is the professional manufacture of seamless precision steel pipe. Cold drawn and cold rolled pipes are our main products, for which we have more than ten years experience. If you have any need, please contact with me.