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Production standards for precision seamless pipes
Date:2019-05-06      Views:279Time      Label:Production standards for precision seamless pipes

Tolerances of the outside diameter:

Diameter between 4 - 30 mm

±0,08 mm

Diameter between 35 - 38 mm

±0,15 mm

Diameter above 42 mm

±0,20 mm

 
  • tolerances of the inside diameter are according to EN 10305-4
  • tolerance of the wall thickness ± 10%

The Main Steel grades for the precision seamless pipes:

EN 10305-1/ EN 10305-4 / DIN 2391

Precision seamless tube with European & German standard

 Application 

for Atuo;for machinery use, Oil cylinder tube, Motorcycle shock reducer steel tubes, Auto shock reducer inner cylinder.

Size(mm)   

O.D.: 6mm-350mm , W.T.: 1-30mm, L: max 24000


Final supply conditions:

Designation

Symbol

Description

Cold finished (hard)

BK

Tubes do not undergo heat treatment following the final cold forming and, thus, have a rather high resistance to deformation.

Cold finished (soft)

BKW

The final heat treatment is followed by cold drawing involving limited deformation. Appropriate further processing allows a certain degree of cold forming (e.g. bending, expanding).

Cold finished and stress-relieved

BKS

Heat treatment is applied following the last cold forming process. Subject to appropriate processing conditions, the increase in the residual stresses involved enables both forming and machining to a certain degree.

Annealed

GBK

The last cold forming process is followed by annealing in a controlled atmosphere.

Normalized

NBK

The last cold forming process is followed by annealing above the upper transformation point in a controlled atmosphere.

 




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