Helical Milling Tool with Forward-Backward Feeding

A helical milling tool with forward-backward feeding, comprising a cutting portion, a neck portion and a handle portion, which are successively connected;

• wherein,
• the cutting portion comprises a front-end cutting section, a circumferential cutting section and a back-end cutting section;
• the front-end cutting section is an structure of end mill or drill bit;
• when the front-end cutting section is the end mill structure, the front-end cutting section comprises four front-end cutting edges symmetrically distributed around a center, which can be fed forward to cut along the axis of the tool;
• when the front-end cutting section is the drill bit structure, the front-end cutting section is conical, comprising two front-end cutting edges symmetrically distributed around a center, which can be fed forward to drill along the axis of the tool;
• the circumferential cutting section is of a cylindrical shape and is of a structure of circumferential milling cutter, whose cylindrical surface is provided with helical cutting edges extending to the front-end cutting edges, and the helical cutting edges can be fed to cut along the radial direction of the tool;
• and
• the back-end cutting section is of a frustum shape, an outer diameter of its large end is matched with a diameter of the circumferential cutting section, and an outer diameter of its smaller end is matched with a diameter of the neck portion;
• the side wall of the back-end cutting section is provided inclined cutting edges extending to the helical cutting edges and can be backward fed to cut along the axis of the tool, the other end of the inclined cutting edges extend to the neck portion.