Edge-free diamond tool head and hole making drill

The utility model discloses a self-edging diamond tool bit and a borer. The self-edging diamond tool bit comprises a tool bit main body which is an arc tabular main body; the cross section of the lower segment of the tool bit main body is rectangular; and the cross section of the upper segment is triangular, trapezoid or parabolic. The utility model reasonably improves the structure of the existing tool bit and the initial working surface is arranged to be triangular, trapezoid or parabolic, so the initial aiguille has little resistance during the drilling process and is easy to chisel in. Meanwhile, along with the drilling of the aiguille, the tool bit wears and tears and the diamond particles originally covered inside are disposed gradually, and when the special-shaped part at the front end wears and tears to certain degree, the tool bit enters into the optimal working state.