A rice polishing machine was developed and tested for cleaning wheat grain. It consists of a feeding unit, cleaning unit, power drive unit and power transmission unit. Four levels ofmoisture content were about [9.9, 12.4, 14.9 and 17.6 % (d.b.)]; three friction surfaces with three static coefficient of friction were [smooth = 0.35, intermediate between smooth and rough = 0.43, and rough surface= 0.51]; four levels of pressure on cleaning chamber were [1.25, 3.75, 6.25 and 8.75 kN/m²] and three speeds of air suction flow speeds of [1.3, 2.8, and 3.4m/s.], were used. The maximum value of cleaning efficiency was 99.93% achieved at, moisture content (M1= 9. 9 %), pressure (P4 =8.75 kN/m²), rough friction surface (F3=0.51), and suction air speed (S3 =3.4 m/s). The minimum value of grain damage was 3.5 % achieved at, moisture content (M4= 17.6 %), smooth friction surface (F1=0.35), pressure (P1=1.25 kN/m²) and suction air speed (S3=3.4 m/s). The minimum value of losses due to polishing was 0.41 % achieved at, moisture content (M4=17.6 %), pressure (P1=1.25 kN/m²), smooth friction surface (F1=0.35) and suction air speed (S1=1.3m/s).