Angle of repose

The angle of repose (critical angle of repose) is the angle a granular material forms with a horizontal surface when it is poured through a funnel to form a cone. The internal angle between the surface of the pile and the horizontal surface is known as the angle of repose. This angle is given by the number (0°–90°). The angle is related to the density, surface area and shapes of the particles and the coefficient of fiction of the material. Low angle of repose means powder with good flowing properties