A hole cutter having an extruded plate cap and methods and apparatuses for making such caps and hole cutters. The plate cap has planar opposing external and internal surfaces with an extruded hub extending axially inwardly from the internal surface. An aperture extends axially through the hub from the external surface. At least a portion of the aperture can be threaded for threaded engagement with a driving arbor. The hub is long enough so that the threaded portion contains at least two full threads. A blade body with a cutting edge is attached to the cap to form a hole cutter.