A soldering or a desoldering tool includes a replaceable tip with a recess adapted to receive a portion of a temperature sensor to measure the temperature of the tip. Positioning the temperature sensor within the tip allows the temperature to be quickly measured so that the temperature near the tip may be more accurately monitored and controlled. The temperature sensor may be also integrated with the heater near the tip such that the temperature sensor is between the tip and the heater and near both of them so that the temperature of the tip is substantially that of the temperature of the heater. A sleeve may enclose the temperature sensor and the heater with a portion of the temperature sensor extending out from the foreward end of the sleeve. The replaceable tip may also have a bore adapted to receive a head protruding from the foreward end of the sleeve to couple the tip at a predetermined orientation with respect to the sleeve. The combination of bore and head allows the replaceable tip to be coupled with the sleeve in a consistent manner so that the temperature of the replacement tips can be measured accurately and dependably.