This specification covers an iron-nickel alloy in the form of strip.

This strip has been used typically for diaphragms, leaf springs, and helical springs, requiring a precipitation-hardenable alloy with a coefficient of modulus of elasticity of -20 to +20 x 10-6 per degree Fahrenheit from -50 to +150 degrees F (-36 to +36 x 10-6 per degree Celsius from -46 to +66 degrees C) after suitable heat treatment, but usage is not limited to such applications.