An emery roller machine is use to pitting / decocting of dal obtain by cracking and scratching of clean dal passing through it. For loosening, the husk to facilitate the subsequent oil penetration this is required.

Gradually the clearance between the emery roller and cage (housing) is narrow from inlet to outlet. Cracking and scratching of husk takes place mainly by friction between dal and emery as the material is passing through the narrowing clearance.

During the operation, some of the dal is de-husk and split which are separate by sieving.