Welded stainless steel tubes – as-welded or annealed

CSM TUBE offers a complete range of welded stainless steel tubes, available either in the as-welded condition (W0) or with in-line bright annealing heat treatment (W2R). Choosing the correct supply condition is critical for subsequent forming and mechanical processing stages, as well as for the performance of the final component.

Dimensions and material range:

• Diameters: from 5.00 mm to 32.00 mm
• Wall thicknesses: from 0.30 mm to 2.00 mm
• Ferritic stainless steels: 400 series (e.g. 409, 441)
• Austenitic stainless steels: 300 series (e.g. 304L, 321)
• Duplex and superaustenitic stainless steels (e.g. 2205 and 904L)
• Nickel alloys (e.g. Alloy 800, 825, 840, 600, 625)
• Dimensional tolerances: ISO 1127 / EN 10217-7 (classes D4, T3)

How annealing heat treatment works

For applications requiring high ductility and structural stability, the company uses in-line induction furnaces operating in a protective atmosphere at the solution annealing temperature specific to the alloy being processed—for example, for austenitic grades this is generally 1000–1050 °C. This process enables:

• restoring metallurgical homogeneity after welding;
• eliminating residual stresses in the material;
• ensuring a clean surface suitable for subsequent plastic deformation.

Supply conditions and W0, W2R, W2Rb classifications

Production is classified based on the main international standards, so as to clearly identify the state of the finished products:

• W0: welded tube from cold-rolled strip, without post-weld heat treatment.
• W2R: welded tube with bright annealing heat treatment.
• W2Rb: welded tube subject to bright annealing heat treatment with weld seam re-rolling to improve internal surface finish.

Tensile and hardness testing

All tubes, whether heat-treated or not, undergo rigorous inspection procedures. Mechanical tests, such as tensile testing (EN ISO 6892-1) and hardness testing (Vickers/Brinell), ensure that mechanical properties comply with the required technical specifications. Test results are continuously recorded and stored in the company’s operating system, ensuring full digital traceability for each production batch.

Contact the CSM TUBE technical department to identify the most suitable supply condition for your forming requirements.