Lead error would be occurred during process thread by NC lathe. Aiming at this issue, accurate thread excess was calculated. This way is simple and effectiveness in practice.

• 摘要用数控车床加工精密螺纹时，在开始段和结束段会出现导程误差。针对这个问题，进行了准确的螺纹裕量计算。在实际加工中，简单易行，效果良好。