The main elements of this experimental unit are a perpendicular pair of thread spindle and nut. A moment is exerted on the spindle by means of a pulley, using a spring balance and cable. Additional weights on the rotary plate influence the axial load of the thread.
Two spindles with trapezoidal threads of different pitch are included. The experimental unit contains three long nuts made of various materials with single pitch and a cast iron nut with double pitch.
The measured values can be used to determine and compare the threads efficiencies.