A pipe threader includes a housing, an electric motor, a battery, a die holder, and a die locking mechanism. The die locking mechanism receives torque from the electric motor and rotates as a result. A cutting die is received in the die holder and the locking mechanism rotationally locks the cutting die in the die holder. The locking mechanism includes a first lock ring and a second lock ring. The pipe threader includes a drive assembly including an electric motor, a multi-stage planetary transmission that receives torque from the motor, and a worm drive that receives torque from the transmission. The pipe threader includes an inertial measurement unit and an electronic processer. The processor receives data from the inertial measurement unit, generates a relative position of the pipe threader by applying a Kalman filter, determining whether the relative position exceeds a threshold, and decreases the motor speed in response.