The stiffness of solids can be characterized by three different elastic moduli, all material properties: the Young's elastic modulus, the shear modulus, and the bulk modulus. All are approximately in the tens or hundreds of GPa. The Young's elastic modulus is convenient to use when stretching long, thin samples. The shear modulus is of interest because shear is what ultimately leads to failure in ductile materials such as metal. The bulk modulus measures the compressive resistance to a uniform surrounding pressure.
In any case, all three are intrinsic material properties that would be identical for any two springs made of the same polycrystalline metal, regardless of their size. Is this what you were looking for?