Indexable drilling tool

An indexable drilling tool, comprising a cutter body, an outer blade and an inner blade, wherein the cutter body comprises a shank portion, a cutting end portion and a peripheral surface located between the shank portion and the cutting end portion, the shank portion and the peripheral surface are symmetric with respect to a rotating central axis of the cutter body, the cutting end portion is provided with a central groove and a circumferential groove communicated with a spiral groove on the peripheral surface, the central groove is arranged adjacent to the rotating central axis, and the circumferential groove is arranged adjacent to the peripheral surface, the outer blade is arranged in the circumferential groove for machining an outer ring area of a hole, and the inner blade is arranged in the central groove for machining a central area of the hole, the inner blade is surrounded by a first upper surface, a first lower surface and a first side surface connecting the first upper surface and the first lower surface, the first upper surface intersects with the first side surface to form multiple identical inner cutting edges, wherein when drilling, a cutting area of the inner cutting edge served as a main cutting edge is located between a central inner point and a central outer point on the inner cutting edge, in a feed direction of the indexable drilling tool, an inner convex cutting portion having a maximum cutting depth is arranged between the central inner point and the central outer point, a distance between the central inner point and the inner convex cutting portion in an axial direction of the indexable drilling tool is H1, a distance between the central outer point and the inner convex cutting portion in the axial direction of the indexable drilling tool is H2, which meets the following requirement:

• 0.9H2≤H1≤1.1H2,
• wherein the outer blade is surrounded by a second upper surface, a second lower surface and a second side surface connecting the second upper surface and the second lower surface, the second upper surface intersects with the second side surface to form multiple identical outer cutting edges, when drilling, a cutting area of the outer cutting edge served as a main cutting edge is located between a peripheral inner point and a peripheral outer point on the outer cutting edge, in the feed direction of the indexable drilling tool, an outer convex cutting portion having a maximum cutting depth is arranged between the peripheral inner point and the peripheral outer point, a distance between the peripheral inner point and the outer convex cutting portion in the axial direction of the indexable drilling tool is H1′, a distance between the peripheral outer point and the outer convex cutting portion in the axial direction of the indexable drilling tool is H2′, which meets the following requirement:
• 0.95H1′≤H2′≤1.1H1′,
• wherein a cutting width of the inner blade is Ae, and a cutting width of the outer blade is Ae′, which meets the following requirement:
• 0.8Ae′≤Ae≤0.95 Ae′.