Micro-reinforced concentric twist drill

A micro-reinforced concentric twist drill, comprising a tool shank, and a tool head, wherein at least two spiral strips are integrally formed on the tool head, for each respective spiral strip, a surface, facing a cutting direction, of the respective spiral strip is formed as a spiral cutting surface, a surface extending backward along an outer edge of the spiral cutting surface is formed as a spiral pair cutting surface, the spiral cutting surface intersects with the spiral pair cutting surface to form a spiral cutting edge, and a surface on a back side of an axial front end of the respective spiral strip is formed as a rear cutting surface;

• rear cutting surfaces on both sides intersect to form a chisel edge, and for each spiral strip, the spiral cutting surface intersects with the rear cutting surface to form a cutting edge, and the spiral pair cutting surface intersects with the rear cutting surface to form a side edge;
• wherein, on both sides of a region of an axial center of the micro-reinforced concentric twist drill, protruding micro-reinforced center drills are symmetrically arranged on the spiral cutting surfaces, and each micro-reinforced center drill extends to the rear cutting surface and protrudes to form a center drilling tool;
• a micro-reinforced central cutting surfaces in-millimetersprotrudes from an inner side of the micro-reinforced center drill, and each micro-reinforced central cutting surface extends axially forward to intersect with the rear cutting surface to form a micro-reinforced center hole drilling edge of the micro-reinforced concentric twist drill;
• and
• on both sides of the micro-reinforced concentric twist drill, micro-reinforced wear-resistant grooves recessed along a direction from the spiral cutting edges inward to the axial center are integrally formed on the spiral cutting surfaces;
• a micro-reinforced wear-resistant cutting surface is formed at a bottom of each micro-reinforced wear-resistant groove along the spiral cutting edge, and a protruding micro-reinforced wear-resistant table is arranged on an inner side of the micro-reinforced wear-resistant cutting surface;
• and each micro-reinforced wear-resistant cutting surface extends forward to intersect with the rear cutting surface to form a micro-reinforced wear-resistant cutting edge.

A micro-reinforced concentric twist drill, comprising a tool shank, and a tool head, wherein at least two spiral strips B are integrally formed on the tool head, for each respective spiral strip, a surface, facing a cutting direction, of respective spiral strip is formed as a spiral cutting surface, a surface extending backward along an outer edge of the spiral cutting surface is formed asa spiral pair cutting surface, the spiral cutting surface intersects with the spiral pair cutting surface to form a spiral cutting edge, and a surface on a top side of an axial front end of the respective spiral strip is formed as a rear cutting surface;

• rear cutting surfaces on both sides intersect to form a chisel edge, and for each spiral strip, the spiral cutting surface intersects with the rear cutting surface to form a cutting edge, and the spiral pair cutting surface intersects with the rear cutting surface to form a side edge;
• wherein, on both sides of the micro-reinforced concentric twist drill, protruding micro-reinforced reamers are symmetrically arranged at center areas of the spiral cutting surfaces spirally extending along the direction towards an axial center;
• a reaming cutting surface protrudes from an inner side of each micro-reinforced reamer, and each reaming cutting surface extends forward to intersect with the rear cutting surface to form a reaming cutting edge;
• micro-reinforced wear-resistant grooves recessed along a direction from the spiral cutting edges inward to the axial center are integrally formed on the spiral cutting surfaces;
• a micro-reinforced wear-resistant cutting surface is formed at a bottom of each micro-reinforced wear-resistant groove along each spiral cutting edge, and a protruding micro-reinforced wear-resistant table is arranged on an inner side of the micro-reinforced wear-resistant cutting surface;
• each micro-reinforced wear-resistant table extends forward to intersect with the rear cutting surface to form a micro-reinforced wear-resistant drill, and each micro-reinforced wear-resistant cutting surface extends forward to intersect with the rear cutting surface to form a micro-reinforced wear-resistant cutting edge.