Hydraulic Rotary Cylinders are suitable for operating Hydraulic Chuck or Collets. This cylinder is mounted on the back side of Lathe Spindle and it operates the chuck or collet through a draw bar attached with piston rod of cylinder. A non-contacting type rotary joint is provided with cylinder which is free from maintenance. This joint gives certain amount of oil leakage for which one outlet is provided. Cylinder is mounted in horizontal position.