Abstract: Thermostat metals combining properties of relatively high flexivity and good corrosion resistance are prepared by metalurgically bonding a corrosion resistant high expansive alloy (1) to a less corrosion resistant low expansive alloy (2) and capping the low expansive alloy (2) with a corrosion resistant, moderately low expansive alloy (3) of similar hardness to that of the low expansive alloy (2).The preferred high expansive alloy (1) is comprised of about 18 wt. % Ni; 11 wt. % Cr; and balance Fe.The preferred low expansive alloy (2) is Invar (36 wt. % Ni; balance Fe).The preferred corrosion resistant low expansive alloy (3) is comprised of about 20 wt. % Ni; 26 wt. % Co; 7 wt. % Cr; balance Fe.The preferred volumetric ratios of the metals is about 50% of the high expansive alloy (1), 30 to 40% of the low expansive metal (2) and 10 to 20% of the corrosion resistant low expansive alloy.