Apparatus for limiting equipment burden when penetrating a mixed or composite material structure including metal utilizing a hammer-drill

A metal drilling system for penetrating metal or rebar encountered during concrete, rock or masonry boring operations comprising:

• a hammer drill configured to apply a torsional moment to a bit coupled to the drill by a chuck and configured with a mechanical hammer capable of ordinarily striking an end of the coupled bit so as to produce a repetitive axial force;
• the drill being configured without a means of deactivation for the mechanical hammer;
• the chuck being configured to transfer the torsional moment to the bit while simultaneously allowing free axial movement of the bit in response to strikes by the mechanical hammer;
• the bit comprising a cylindrical body formed with a first and second cylindrical sections;
• wherein the first section comprises a shank section having a longitudinal end;
• wherein the second section comprises a cutting section of a selected diameter to bore a desired diameter hole;
• and
• a minimum of one protuberance coupled to the shank at a point a first distance from the longitudinal end of the shank section, wherein the first distance prevents full insertion of the shank section into a drill chuck cavity by creating a gap that prevents the mechanical hammer from striking the longitudinal end of the shank section when the hammer-drill is in operation;
• wherein the second section provides sufficient contact for boring through metal or rebar encountered during concrete, rock or masonry boring operations while being driven by the torsional moment of the drill;
• and
• the cutting portion of the bit being configured with a geometry selected for effectiveness in boring through metal when driven by the torsional moment.