Unequal-helical-angle end mill with gradually increased core thickness

The invention relates to a three-tooth unequal-helical-angle end mill with a gradually increased core thickness. The three-tooth unequal-helical-angle end mill comprises a handle part and a blade part. The blade part comprises helical grooves, main cutting edges and auxiliary cutting edges, the main cutting edges are distributed on the cylindrical surface, and the auxiliary cutting edges are distributed on the end surface. Due to the fact that the included angles between three main cutting edges of an unequal-helical-angle end mill and the axis are different, in other words, the unequal-helical-angle end mill is of an asymmetric structure, certain eccentricity exists, and the requirement for dynamic balance of the tool cannot be met. The core thickness of the three-tooth unequal-helical-angle end mill, namely the depth of the helical grooves, is gradually increased from one end of the end surface to one end of the handle part, the sectional area of the helical grooves is increased, the structure of the tool i