Self-centering drill bit with pilot tip

A self-centering drill bit, which comprises:

• an elongated drill body formed from a single piece of stock material;
• the elongated drill body having a shank end, intermediate section and working end;
• flutes formed in the drill body with each flute having a continuous uninterrupted surface extending from a juncture of the shank end and the intermediate section to a free end tip of the drill body at the working end;
• the working end of the drill body being formed with a first section of a prescribed major drill diameter and including major cutting lips arranged in an inversely angled configuration;
• the working end of the drill body being formed with a stepped second section which is formed integrally with and extends from the first section in a direction away from the shank end of the drill body;
• the second section of the drill body formed with a minor drill diameter smaller than the prescribed major drill diameter, and
• the second section of the drill body being formed with minor cutting lips.

A unitary self-centering drill bit, which comprises:

• an elongated unitary drill body having an integrally formed shank end, intermediate section and working end;
• the working end of the drill body being formed with a free end tip;
• a pair of flutes formed in the drill body with each flute having a continuous uninterrupted surface extending from a juncture of the shank end and the intermediate section to the free end tip of the drill body at the working end and from side to side of each flute;
• the working end of the drill body being formed with a first section of a prescribed major drill diameter and including major cutting lips arranged in an inversely angled configuration;
• the major cutting lips being contiguous with the continuous surfaces of the respective flutes;
• the working end of the drill body being formed with a stepped second section which is formed integrally with and extends from the first section in a direction away from the shank end of the drill body;
• the second section of the drill body formed with a minor drill diameter smaller than the prescribed major drill diameter;
• the second section of the drill body being formed with minor cutting lips;
• the minor cutting lips being contiguous with the continuous surfaces of the respective flutes;
• the second section of the drill body formed with at least a pair of outer surfaces each having a forward edge contiguous with one of the pair of flutes and a trailing edge contiguous with the other of the pair of flutes with each outer surface being continuous between the forward and trailing edges thereof;
• and
• at least the first section and the second section of the working end of the drill body being formed in a single piece of material and in a step-drill-bit configuration.

A unitary self-centering drill bit, which comprises:

• an elongated drill body having a central axis and an integrally formed shank end, intermediate section and working end formed in a stepped-drill-bit configuration;
• flutes formed in the drill body with each flute having a continuous uninterrupted surface extending from a juncture of the shank end of the intermediate section to a free end tip of the drill body at the working end;
• the working end of the drill body being formed with a first section of a prescribed major drill diameter and including major cutting lips arranged in an inversely angled configuration;
• the working end of the drill body being formed with a stepped second section which is formed integrally with and extends from the first section in a direction away from the shank end of the drill body;
• the second section of the drill body formed with a minor drill diameter smaller than the prescribed major drill diameter;
• the second section including a web having portions which extend radially outwardly in all directions from the central axis of the drill body, and
• the second section of the drill body being formed with minor cutting lips located on diagonally opposite sides of the web and spaced radially from the central axis of the drill body.