Abstract: A hole saw plug ejector includes a mandrel having a threaded end and a hole saw cup with cutting teeth on a leading edge to cut a hole in material. A pilot bit is provided in the hole saw cutting end of the mandrel. A retaining nut for holding the hole saw cup to the mandrel includes inner and outer threads. The inner threads engage the threads on the mandrel and an ejector spring engages the outer threads to provide a simplified system for changing ejector spring sizes for different sizes of hole saw cups.