The invention relates to a rice-polishing machine sieve profile. In one embodiment this is accomplished by an elongate, tubular shaped sieve arrangement with a polygonal profile, comprising a cam essentially cylindrical shape co-axially arranged” within the sieve arrangement such that between an inner surface of the sieve arrangement and a jacket-surface of the cam a polishing chamber has a maximal and a minimal radial distance between jacket-surface of the cam and the inner surface of the sieve arrangement, characterized in that the number of corners of the polygonal profile is larger than 8.