Heat treatment: Hot finished and cold finished tubes shall be heat treated at a temperature of 650℃ at least. And full annaealed,Website:http://www.lksteelpipe.com, isothermal annealed, or normalized and tempered condition at the option of the manufacturer, the minimum tempering temperature shall be not less than 650 ℃. Mechanical Tests Required: Tension test Flattenting Test Hardness test Hydrostatic or Nondestructive Electric test