According to table values there is a slight difference in Poissons ration between different low alloy steels. Why is that? In the elastic region I would have guessed that there was only a change in atomic distance during strain. Acocording to my thinking low alloy steels have the same kind of atomic bonds, thus having the same Youngs modulus and Poissons ratio. My question is: what mecanisms/properties of the material determines the Poissons ratio? Is it possible to "control" the Poissons ration in steel during production?