When the nut and bolt stuck, avoid using excessive torque hard pull. If the temperature is higher, and so should wait until the bolt down to standard temperature, poured little oil to the internal thread, activity back and forth the nut with the appropriate torque, and at the same time with a large hammer vibration. May also be suitable heating nut, gradually smooth the burr in inner thread and remove it . When the nut can not be removed, please be skilled gas welders to torch cut the nut and protect the srew