Abstract: The present invention provides an ice fishing hole chamferer 10 with an elongated shaft 20 for inserting into an ice fishing hole 160 having a top end 60 and a submerged end 30 with an axle 40 and an axis 50, and a propeller 90 having a cutter side 96 with at least one cutter 94 and a thrust side 98 configured for propelling water, said propeller having a hub 80 for connecting to the axle and at least two radiating propeller blades 92, wherein the propeller blades are hinged to the hub to move between a narrow closed position less than the diameter of the ice fishing hole 160 and situated along the axis of the elongated shaft and an extended open position greater than the diameter of the ice fishing hole and angled for chamfering the bottom 162 of the ice fishing hole at a chamfering angle 128, and a propelling means 70, 110, 100 for rotating the propeller, wherein the propeller revolves about the axis and the propeller blades are configured to centrifugally extend to the extended open position and thrust upw