Shape: The tubes shall be furnished in the following shapes, as specified by the purchaser: round, square, HEXAGON, rectangular and special sections.
Chemical Composition& Mechanical Properties(Type: Cold Drawn Seamless Mechanical/CDS)
Final supply conditions
|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.|
NOTE THE RADIUS “R” CORNER.