Hole-saws are provided herein, and more specifically to hole-saw assemblies and processes having adjustable platters for multiple simultaneous saw components, optional elimination of a guide drill, and the ability to retrieve cores of a sawed work piece before sawing completely through the workpiece. One hole-saw device, may have a motive force; a base plate rotatable by the motive force; cutters; and locking mechanisms to mount the base plate to the cutters.

A hole saw having an internal saw with a circular sidewall including a working end including teeth and a backwall connected to the sidewall. The backwall includes an aperture concentrically located with respect to the circular sidewall for receiving a pilot drill designed to extend beyond the working end of the circular sidewall. The hole saw also has an external saw with a circular sidewall with a greater diameter than the circular sidewall of the internal saw. The circular sidewall of the external saw has teeth and an oppositely located proximal end that includes tangs separated by notches. A base plate is fastened to the circular sidewall of the external saw. The base plate includes a plurality of apertures for fixing the base plate to the backwall of the internal saw and locating the circular sidewalls concentric with respect to each other.