Laboratory Size, hammer type with H.P. heavy duty motor (single phase) 220 volts, 50C/s A.C. consisting of four steel hammers fixed to a disc of 3" in dia 1" thick through which passes a shaft being revolved at 3000 RPM. The hammers are enclosed in a C.I. drum, the sides and upper surface of which are roughened in a C.I. drum, the sides and upper surface of which are roughned. The inner surface is undulating. The lower part of drum is made of chrome plated brass and is detachable so that SS sieves of different mesh size (a set of three sieves of coarse, medium & fine) supplied with the instrument can be easily placed. Hopper is made of die casted aluminium, built on angle iron frame of size 24" x 14" x 20" high.