Welded steel tubes cold precisely calibrated - description
The cold precisely calibrated longitudinally welded tubes are made of cold rolled steel strip. In order to achieve a perfect and homogenous weld with a minimum heat affected zone a resistance welding is made on a D.C. welding line. The tubes are supplied in a quality satisfying the DIN standards specified in the tables.
Specifications:
| Comparable standards - CSN EN | 10305-3 |
| Comparable standards - CSN | 42 6713 |
| Comparable standards - DIN | 2394-1 |
| Comparable standards - GOST | |
| Diameter [mm] | 8,00 - 200,00 |
| Wall thickness [mm] | 0,50 - 3,00 |
| The delivery standards | CSN 42 0142, CSN EN 10305-3, DIN 2394-2. |
Material quality:
Offer of steels by:
| EN 10305-3 | E155, E190, E195, E220, E235, E260,E275, E320, E355, E370, E420 |
| CSN | 11320, 11343 |
| DIN | St12, USt34-2 |
| GOST | 08kp |
Profile and size program:
download
Surface finish:
Welded tubes precisely calibrated are supplied in bright and smooth inner and outer surface finish. Surface defects and scores which do not exceed the wall thickness tolerance limits are allowed. Even though the external collar of the weld is removed, the seam may still be visible. The inner collar is not removed and its height will not exceed 0,2 mm.
Heat treatment:
As required by the customer:
- without heat treatment (BK condition according to DIN standard)
- normalized (NBK condition by DIN standard)
Lengths and tolerances:
| The range of lenghts | Lenghts [m] | Tolerances [mm] |
| Manufactured | 2 - 7 | |
| Approximate | 2 - 7 | ± 250 |
| Precise | 2 - 7 | + 100 |
| Service | 0,3 - 2 | ± 0,5 |
Tolerance limits of outer diameter, wall thickness and traightness meet the appropriate standards. The weld quality is inspected by non-destructive testing. Following an agreement, the hydraulic pressure test may be applied, too.
Packing and designation:
Precisely calibrated welded tubes are supplied in band-blocked bundles which weigh 2500 kg or in other required weight. Following an agreement, single bundles can be wrapped in paper or foil or packed into cases and the ends of bundles can be protected by wooden crates. Each bundle is fitted with the producer's label containing the data as follows:
- size
- steel grade
- lengths
- heat number
- weight in kg, by agreement length in m and number of pieces
- customer
During transport the tubes are protected by a preservation agent against atmospheric corrosion.
