A system for crushing material that may include a compaction chamber and a screw assembly that generally extends between the proximal and distal ends of the compaction chamber. In one embodiment, a portion of the screw assembly increases in diameter along a length of the shaft of the screw assembly such that the system is configured to crush material between the compaction chamber and the portion that increases in diameter. The portion that increases in diameter may be integral with the shaft of the screw assembly. An embodiment of the system may also include at least one wear member that is removably associated with the distal portion of the compaction chamber such that the wear member may assist with crushing. Further embodiments may include improved input, discharge, and/or jam clearance means for a screw crusher or other types of screw or auger systems.