The present subvolume IV/19B4 forms the continuation of IV/19B3 and contains evaluated data for elements and Binary Systems from Mn-Mo to Y-Zr appearing in alphabetic order of the elements in the chemical formulae. The volume is accompanied by a CD, which allows computer calculation of a range of solution properties for selected temperature and phase composition ranges for the systems presented in that particular volume. Graphical representations, including the calculated phase diagram for each system, are also possible. Information on more comprehensive software, allowing complex equilibrium calculations involving both pure substances and solution phases of different types (e.g. slags, salt systems, aqueous solutions, etc.), can be obtained from SGTE members. A list of the SGTE membership is presented in the cover pages of this volume.