An ice maker includes a casing that defines a chamber. The casing extends between a top portion and a bottom portion. An extruder die is mounted to the casing at the top portion of the casing. An auger is disposed within the chamber of the casing. A radial sleeve bearing engages the auger at the bottom portion of the casing. A radial and thrust bearing engages the auger at the extruder die. A related refrigerator appliance is also provided.