Stress state detection device for external thread of drilling tool

A stress state detection device for an external thread of a drilling tool belongs to the nondestructive testing technology field. A positioning clamping mechanism comprises a latch pull bar, a latch wrench, a right supporting ring, a latch stand, a latch, a vertical rod, a supporting ring accessory, a left supporting ring, adjusting springs and adjusting nuts. A sensor detection mechanism comprises a sensor housing, a sensor mounting ring, L-shaped flat springs, flat spring cover plates, a small slide bar, a linear bearing, an adjusting disc, screws and a spacing disc. The sensor housing is fixed on the sensor mounting ring via pivot pins. A motor drive mechanism comprises a motor sheath, a stepping motor, a motor supporting ring and the vertical rod. The stepping motor is disposed inside the motor sheath and is connected with the motor supporting ring through a fastening screw, and the motor supporting ring is in threaded connection with the vertical rod. The stress state detection device is high in structur