Abstract
A universal relation, proposed by Stauffer, Ferer and Wortis, between the scale factors in the scaling functions for the free energy and two-spin correlation function, is shown to be valid for the spherical model with general pair interactions, provided an appropriate definition of the correlation length is adopted. The hypothesis remains valid for the spherical model and numerically for the three-dimensional Ising model, when extended to include the scale factor for the magnetic field.