Magnetic sensors are fabricated with an initial length that is slightly longer than their finished length. The sensors are then critically lapped and exposed for target signal output. The final target length of the sensors is obtained by first exposing the sensors to a photolithographic process and then directly lapping the excess length from the sensors. The length of sensor material that is removed is in the range of several nanometers. The target end point during lapping may be ascertained by detecting the change in resistance between the sensor and leads in the lapping tool as the excess material is lapped from the sensor.