As used in thermal switches. Instead of in form of a bimetal strip and
continuous curving with temperature, these are 0.5 inch diameter and make a
definite flip from concave to convex at a specific temperature. About 1mm of
abrupt movement gives a very positive transition for the switch contacts.
Would it be possible to change the characteristic temperature by grinding
back a spot/ring/radii? on one face? which face? or would it just destroy
the action/activation force?