根据冷挤压成形机理推导出内螺纹底孔尺寸计算的理论公式，通过实验研究了底孔尺寸对挤压扭矩和牙高率的影响，并对理论公式进行了修正。 According to the cold extrusion forming theory, the theoretical formula for calculating the size of the bottom hole of the female thread was deduced. The influence of the size of the bottom hole on the extrusion torque and the tooth height was experimentally studied, and the theoretical formula was revised.