The circular-throw vibrating screen generates a rotating acceleration vector and the screen must maintain a steep throwing angle to prevent transportation along the screen deck. The deck is commonly constructed to have an angle within the range of 10° to 18°, in order to develop adequate particle movement. An Increase of deck angle speeds particle motion with proportional relationship to particle size. This decreases residence time and size stratification along the mesh screen. However, if the angle is greater than 20°, efficiency decreases due to reduction of effective mesh area. Effect of deck angle on efficiency is also influenced by particle density. In mining the optimal inclination angle is about 15°. Exceptions are the dewatering screens at 3° to 5° and steep screens at 20° to 40°.