"Elastic modulus" is a material property that indicates the strength or elasticity of the steel materials used for making mold parts. The elastic modulus is also called the "Young's modulus" usually. The elastic modulus is the coefficient of proportionality between the "strain" and the "tensile stress" when the steel material is pulled. This relationship can be expressed by the following equation.

　σ＝EXε

ε: Epsilon
σ: Sigma

In other words, "stress is proportional to strain".

The physical value of the elastic modulus is determined by the type of the metallic material. In general, a material with a larger value for the elastic modulus has a higher tensile stress or rigidity.

The data of the elastic modulus is shown in Table 1 for some typical metallic materials.