The Oguchi approximation is shown to give an upper bound on the magnetization for spin 1/2 Ising models with arbitrary ferromagnetic pair couplings. The resulting bound on the critical temperature is shown to better than the mean field bound. For ferromagnetic spin-1/2 models where the threebody approximation predicts a unique magnetization, this too is shown to give a magnetization bound and an even better bound on the critical temperature.