Friction coefficient of cereal grains on various surfaces

The static coeff. of friction of 3 materials which could be used in the construction of silos were determined for oats and shelled maize at different m.c. within a range of 10-20% (w.b.). In general, the coeff. increased with increasing m.c., except for maize on concrete for which changes in m.c. seemed to have no effect. The values varied from 0.216 for mild steel on the driest oats to 0.598 for concrete on the wettest maize. The coeff. for maize were generally higher than for oats for the materials tested. The tests were carried out by rotating the annular plates on the grain surface using an open tray and recording the max. shear stress due to friction.