The Sub Series consists of all types thread for HDD drill pipe connecting and Pin/Box protecting block,which are forged with texture of 37CrMnMo to improve the strenth of extension,twisty,crush and press.The thermal treatment ensures the tenacity.The nitrogenized thread reacts on anti-corrosion and stick.All the subs must be detected by magnetic powder before leaving factory.
All process we did ensure the security of your construction!