Abstract: A vertical shaft rock crusher has a frame attached to its outer shell to which a support ring is horizontally mounted. A plurality of breaker plates are disposed on the support ring in an interlocked arrangement. The breaker plates are disposed in a staggered array to form rings of breaker plates stacked in a brick-like manner and require no mounting hardware. One breaker plate embodiment has a relatively smooth circumferentional surface, another have V-shaped grooves disposed in the rock crushing surface. A third embodiment has pockets formed between the stacked rings. Interconnection of adjacent breaker plates, in one embodiment of interconnection structure is accomplished by forming a slot on one side of the breaker plate and a mating post on the other side, such that adjacent plates may be interlocked to each other.