Abstract: A grinding assembly (10) for a grinder pump (13) has disk member (11) rotatable within an opposing annular ring (12). The inner circumferential surface (34) of the annular ring (12) carries a plurality of cutting teeth (41, 42), which partially extend at an angle along the lateral dimension of the inner circumferential surface (34). Disk member (11) has an annular edge (50) which separates a side (51) distal to the pump inlet (17) and a side (52) proximal to the inlet (17). At least one projection (60) extends from the distal side (51) and has a leading edge (63) facing toward the direction of normal shaft rotation. At least one cutting member (70) extends from the proximal side (52) and also has a leading edge (74). Proximal side (52) has a recess (80) forming first and second cutting edes (82, 84). Similarly, distal side (51) has a recess (90) having first and second cutting edges (93, 94). Proximal recess (80) overlaps distal recess (90) along the width of annular redge (50).