Well known is te relation between Young and shear moduli within region of proportional ity G=E/(2+v), v -a Poisson ratio. The formula implies that axial strain and shear angle are little enough for their proportionality with normal and tangent stresses. If we use a short and axially compressed beam (stub) to obtain the shear diagram what kind of link is expected to be between nonlinear compressive diagram and shear modulus G? May be the Young modulus should be simply substituted by the tangent modulus Et=d_sigma/d_epsilon? What experimental facts are available?