1. American Piping Products Inc.
2. Anand Seamless Tubes Pvt. Ltd.
3. ArcelorMittal SA
4. BENTELER International Aktiengesellschaft
5. Bri-Steel Manufacturing
6. Continental Steel & Tube Co.
7. Global Seamless Tubes & Pipes Pvt. Ltd.
8. Husteel Industry Group
9. JFE Steel Corporation
10. Jindal Steel and Power Limited
11. Michigan Seamless Tube
LLC
12. Nippon Steel Corporation
13. Permanent Steel Manufacturing Co. Ltd.
14. Shandong Rigang New Material Co. Ltd.
15. Shanghai Metal Corporation
16. SMS group GmbH
17. Suraj Limited
18. Tenaris S.A.
19. The Federal Group USA.
20. Tianjin Pipe Corporation
21. TMK Group
22. TUBACEX
S.A.
23. U . S. Steel Tubular Products
24. Vallourec Group
25. Venus Pipes and Tubes Limited
26. Voestalpine Rotec GmbH
27. Weatherock Group Holding Limited
28. Zaffertec S.L.
29. ZQ Steel Group Co. Ltd.