Abstract: A thermostatic switch has a bimetallic member formed with an undulated section for causing both an axial and a radial displacement of the bimetallic member such that each time the member expands a first contact wipes across a second contact. By providing sufficient undulations, the wiping action occurs prior to and after separation of the contacts preventing the build-up of a resistive residue which could interfere with switch operation. Utilizing the undulated bimetallic section in a thermostatic switch increases the life of the contacts and reduces variations in temperature responsiveness.