Replacable screen with frame

A rectangular screen deck comprising a support frame having a plurality of frame elements defining a plurality of apertures therein and a plurality of unitary screening panels each panel having a peripheral surface abutting the peripheral surface of adjacent panels in side by side and edge to edge relationship, each panel being disposed on the support frame element over each aperture therein, said support frame elements being provided with spaced openings around each aperture, each screen panel comprising a wear resistant plastic material and having a plurality of screening apertures inwardly of its peripheral region and including a plurality of spigot-like protrusions spaced along its peripheral region, the protrusions projecting transversely to the plane of said panel and being integral with the panel and of the same material as the panel and solid where they project from the panel, said protrusions matingly engaging the corresponding openings in said support frame elements for replaceably securing said panel to said support frame, said protrusions each having a shoulder below and adjacent a lower edge of said opening for resisting withdrawl from the openings.