Seamless pipes

Our company is interested in buying weldless pipe size: ø 273 ø 298,5 ø 327 ø 377,6 ø 355,6 ø 377,6 ø 426 ø 488
Requirements for material:
- limitless weldability assurance;
- resistance to rupture ?? not less than 530,
- flow limit not less than 0,2 390.
Requirements for material for pipes: ø 273 ø 298,5?20 ø 327 ø 377,6:
- material must provide HFC hardening till hardiness not less than 50 HRC width till 4 mm.