According to different manufacturing(mfg), seamless steel pipe can be divided into hot rolled pipe, cold rolled pipe, cold drawn pipe and extruded pipe.
Hot Rolled Process for Seamless Steel Pipe
Round Pipe Billet → Heating → Punching → Three-Roller Skew Rolling, Continuous Rolling or Extruding → Pipe Detaching →
Micro Tension Sizing or Reducing → Cooling → Straightening → Hydrostatic Test or Inspection → Marking → Warehousing
Cold Drawn Process for Seamless Steel Pipe
Round Pipe Billet → Heating → Punching → Pipe Head Treatment → Annealing → Acid Pickling → Coating Oil → Multi-pass
Cold Drawing → Pipe Billet→ Heat Treatment → Straightening →Hydrostatic Test or Inspection → Marking → Warehousing