Abstract: A guide plate assembly, mountable on the table of a saw which guides a sheet rotatably fixed to the guide plate to enable the saw blade to cut the sheet into a circular disk of a desired diameter. The assembly includes a first slide bar that may be latched in position in a miter slot of the saw table, with a plate attachable to the first slide bar that is slidably latched to the first slide bar, and a second slide bar fitted with one or more cylindrical pivot holes which is also slidably latched in an open slot of the plate. A pivot screw, in the form of a wood screw fitted with a cylindrical head is fastened to the center of a sheet, to be cut, and the cylindrical head rotatably mounted in a pivot hole of the second slide bar, so that the sheet may be circularly rotated about the cutting edge of the saw blade.