With mathematic analysis the end section curve of front blade of twist drills is induced into generalized involute; with vector analysis the mathematical model for working of spiral surface is founded and the characteristic formula derived to use CAD in working design of twist drills and screw drills.
通过数学分析将麻花钻前刃面端截面曲线归纳成广义渐开线;用矢量分析法对螺旋面的加工建立数学模型并推导出特征方程,以便实现麻花钻、螺钻加工设计。