ABOUT COMPOUND SCREW

 WHAT IS COMPOUND SCREW ?

• Why compound screw ?

           Whenever the fast movement of the screw is required, multi-start threads can be used. However,                 multi-start threads may affect the self locking property.

           In order to achieve the fast movement of the screw without affecting the self locking property , a                 compound screw is used.

• Compound screw :

          Compound screw consists of two screws in series having opposite hands, arranged such that the                  resultant motion is the sum of individual motions of the two screws.

          The cod screw, consists  of  the lower screw with pitch and the upper screw with pitch.

   

• Whenthe handle attached to the nut is turned through one revolution in clockwise direction viewed from top, the top screw advances by a distance in upward direction.