Abstract: An interlocking clamping system for the components of a sieve deck having a foraminated surface defined by rows of stainless steel profile wire held in laterally spaced relation to each other on transverse support rods for processing granular material. The interlocking clamping system eliminates the need for providing a heavy reinforced frame around each modular screen section by including as a part of the clamping system pairs of elongated retainer bars between longitudinal rows of modular screen sections. Each retainer bar receives and retains corresponding ends of the transverse support rods in a plurality of modular screen sections. Locking pins extend through sockets in the retainer bars to releasably connect the modular screen sections to an underlying base. The removal and replacement of individual screen sections is possible when desired without disturbing the other screen sections. A movable dam is provided with an effective seal to prevent leakage between adjacent screen sections.