钻具螺纹部位在钻具的服役过程中由于受到较大而复杂的载荷作用，容易发生应力集中而造成疲劳损伤。当应力集中达到一定的程度时会使钻具螺纹失效，进而对生产带来严重影响。降低应力集中程度的有效方法之一是对螺纹进行修扣处理。目前现场对修扣处理过程存在一定的盲目性，缺乏一定的检测技术指导。使用磁记忆检测方法来分析钻具螺纹的应力集中程度在修扣前后的变化，验证螺纹修扣在降低螺纹应力集中程度的有效性，并判断出钻具螺纹修扣后的应力集中程度的状态等，为现场提供有效的技术支撑。

The thread of drilling tools is subjected with large and complicated stresses in drilling process, and it easily tends to generate fatigue cracks due to stress concentration. When the stress concentration develops to a certain extent, it will make a failure of the thread of drilling tools, and then this may bring serious impacts on the production. Repairing the thread is one of the effective ways to reduce the stress concentration. But the workshop is always blind to the repairing of the thread, and it lacks technical guidance to test. According to the theory of MMMT(Metal Magnetic Memory Testing), one can use MMMT to analyse the differences of the stress concentration of the thread before and after repairing, and to verify the effectiveness of the thread repairing. Also one may judge what state of the stress concentration of the thread is. In short, one may offer the guidance for the workshop to repair the thread.