Will it hold? How strong does the support cable of an elevator have to be in order to transport people and goods safety? Which materials are suitable for constructing bridges which are economical and at the same time as safe as possible? How hard is some particular material, and what does hardness mean anyway? In the DLR_School_Lab we will use a testing machine to determine the characteristics values of hardness and tensile strength for a material. In the process we will compare different material samples and how they behave under various physical conditions.