Now begin a block of issues where we see some of the properties of the materials used in engineering, starting with his first song by the mechanical properties of materials, properties that will be very useful for the formation of our students, future engineers, and properties are valued at the materials in their role as structural materials. This issue dedicated to the study of mechanical properties, will address not only the study of the properties as such, but also the necessary tests for the evaluation of these properties in different types of structural materials. The following topics will deal with the physical behavior of materials characterized by a variety of electrical, magnetic and thermal properties. In item 9 will show that the atomic structure, in particular, the band of energy between electrons in the valence band and conduction for classifying materials as conductors, semiconductors and insulators. Item 9 analyze the magnetic behavior of materials and item 10 will be devoted to describe the thermal properties of materials in a simple and summary.