• Efficiency of screw thread.
  • Mechanical advantage.
  • Determination of the friction loss.
  • Comparison of lubricated and un-lubricated screw threads.
  • Comparison of actual results with theoretical.
  • Determination of velocity ratio.


  • Approximately Ø250mm turntable
  • 20mm outside dia meter thread
  • 5mm thread pitch
  • The effort can be applied to raise or lower the load
  • Set of weights
  • Comprehensive instruction manual provided

This simple screw jack is based around a bench-mounted base incorporating a turntable fitted with a metric square pitch screw jack thread. The apparatus is stood on a firm bench and a cord is
wound around the periphery of the turntable. The free end of the cord is threaded over a pulley and then hangs vertically to accept the load hanger supplied. A set of calibrated weights is supplied which are suspended from the load hanger thus producing a known torque on the system. To adjust the experimental parameters further the calibrated weights can also be applied to the top surface of the turntable. A comprehensive instruction manual for lecturer and student, giving full details on apparatus assembly and operation as well as example results. All necessary assembly and operational tools are provided.