alloy, which consists 52 % Fe, 32 % Ni, 5 % Co with an expansion coefficient smaller than invar but over a narrower temperature range (compare: invar), sulam, mis sisaldab 52 % Fe, 32 % Ni, 5% Co, mile soojuspaisumistegur on väiksem invari omast, aga suurem kitsamas temperatuuriintervallis (vrd invar)