Drilling milling tool and methods for producing a through-hole

A method for producing a through-going bore (210) in a metallic workpiece (200) using a drilling and milling too! (100) having a drilling and milling shank (120) which has a plurality of circumferentially-cutting cutter tips (151, 152, 153, 154) and a plurality of front-end cutter tips (131, 132), at a leading end of the shank, such that at least one of the front-end cutter tips at the end (132) is, at a same time, a circumferentially-cutting cutter tip having a radially outermost cutting point or cutting edge section that projects beyond the circumferentially-cutting cutter tips (151, 152, 153, 154) in a radial direction, the circumferentially-cutting cutter tips (151, 152, 153, 154) are made with straight cutting edges, and together the straight cutting edges produce a cylindrical cut contour, the method comprising the following which are carried out in one working operation:

• drilling through the workpiece (200) by a forward-feed movement (A) of the drilling and milling tool (100);
• stopping the forward-feed movement (A) of the drilling and milling tool (100) as soon as the circumferentially-cutting cutter tips (151, 152, 153, 154), on the drilling and milling tool (100), are located inside the bore (210) just produced;
• and
• orbital milling (Z) of an inside surface (220) of the bore.

A method of producing a through-going bore (210) in a metallic workpiece (200) using a drilling and milling tool (100) having a drilling and milling shank (120) which has a plurality of circumferentially-cutting cutter tips (151, 152, 153, 154) and a plurality of front-end cutter tips (131, 132), at a leading end of the shank, such that at least one of the front-end cutter tips at the end (132) is, at a same time, a circumferentially-cutting cutter tip having a radially outermost cutting point or cutting edge section that projects beyond the circumferentially-cutting cutter tips (151, 152, 153, 154) in a radial direction, the circumferentially-cutting cutter tips (151, 152, 153, 154) are made with straight cutting edges, and together the straight cutting edges produce a cylindrical cut contour, the method comprising the following carried out during one working operation:

• drilling through the workpiece (200) by forward-feed movement (A) of he drilling and milling tool (100);
• either face-miffing or fiat countersinking an edge of the bore at an end of the forward-feed movement (A);
• withdrawing the drilling and milling tool (100) and stopping the withdrawing movement (B) as soon as the circumferentially-cutting cutter tips (151 152, 153, 154) are located inside the bore (210) just produced;
• and
• orbital milling (Z) of the inside surface (220) of the bore.