Circuit breaker calibration screw

The invention relates generally to circuit breakers and, in particular, to circuit breakers having an improved calibration screw. The invention further relates to an improved method for calibrating a circuit breaker bi-metal to a permanent setting. A molded case circuit breaker that includes a double headed calibration screw. The calibration screw has a first and second end with identical convex tip surfaces and screw driver engagement surfaces. The convex tip surface is suitable for engaging a bi-metal thermal overload element. The screw driver engagement surface is suitable for applying a screw driver to adjust the calibration screw position in order to adjust the deflection of the bimetal and calibrate the thermal overload protection. At least one calibration screw planar surface allows for improved sealant injection to permanently fix the screw position and associated calibration setting following adjustment.