Manufacture: tubes to GB/T 6479 shall be manufactured by hot rolled or cold drawn.
Heat Treatment: the tubes shall be produced by heat treated, WT≤30mm normalizing & tempering, WT>30mm quenching & tempering or normalizing & tempering.
Inspection & Test: chemistry composition analysis, tension test, flattening test, flaring test, impact test, macroscopic examination, non-metallic inclusions, NDT, surface inspection and dimension check.
Length: 4000mm; 6000mm; 9000mm; 12000mm; and so on.
Max developed length: 30 meters, also U bending, finning, studded process can be provided.
Option: shot blasting on the outside surface to remove mill scale, make the surface matte colour; surface polishing as preparation work done for further processing, for instance finning.
OD: Φ50-325mm.
WT: 3-55mm.
Tolerance of OD: ±0.75%.
Tolerance of Wall thickness: -10%——+12.5%.
Roundness of the inner and outer diameters: 80% of the tolerance of the outer diameter is not exceeded.
The inclination of the end face: ≤2mm.
Straightness: 1mm/1m.
