The reason of thickness of pipe end increasing in tension reducing is analyzed.The principle and method of cutting end control (CEC) are introduced. The key problems are discussed.

• 分析了钢管在张力减径过程中产生管端增厚的原因，阐述了切头端控制（C．E.；C）的原理、方法；并就其关键问题进行了探讨。