Drill bit

A drill bit includes a body having a first end, a second end opposite the first end, and an axis of rotation extending centrally through the body from the first end to the second end. Body defining an outer diameter. The drill bit also includes a shank adjacent the second end of the body, and a cutting head configured to be coupled to a tool, the cutting head adjacent the first end. The cutting head includes a plurality of axially stacked, dimensionally tapered steps, the plurality of axially stacked, dimensionally tapered steps including a first step and a termination step, the termination step being located between the first step and a first end of the body. The diameter of the step increases from the first step to the termination step. The terminal step has a diameter less than or equal to the outer diameter. 一种钻头，包括主体，其具有第一端，第二端和旋转轴线，第二端与第一端相对，旋转轴线从第一端到第二端穿过主体居中地延伸。主体限定外径。钻头还包括柄和切割头，柄与主体的第二端相邻，柄被配置为联接至工具，切割头与第一端相邻。切割头包括多个轴向堆叠的、尺寸渐变的台阶，多个轴向堆叠的、尺寸渐变的台阶包括第一台阶和终端台阶，终端台阶位于第一台阶和主体的第一端之间。台阶的直径从第一台阶到终端台阶增加。终端台阶具有