Abstract: Integrally formed, elastomer screen units having a multiplicity of sorting apertures therein are provided for longitudinal and transverse connection in multiples to form screen bodies for sizing and sifting fragmented, hard-stock materials, each unit comprising a generally rectangular, preferably integral construction having upper and lower surfaces and first and second edges. The shaping of the first edge is preferably complemental to the shaping of the second edge and the same complemental relationship is true of the left and right lateral side edges of the unit. The units connected together in multiple are supported and mounted for hinge action on rods or stiff wires which extend transversely of the direction of flow of material along the shaker box or screen body.