The use of appropriate materials is fundamental to all engineering applications. The properties of materials are ultimately dependent on the microstructure. The behaviour of materials is dependent on how these characteristics react to or interact with forcing conditions. External forces applied to a structure must be safely accommodated through internal distribution of stress within elements of the structure. Material characteristics dictate how this distribution occurs and appropriate characterisation is therefore necessary. Fundamental equations of equilibrium are used to calculate overall stability, internal stress distribution and conditions under which failure would occur. This unit highlights the dependency of material properties on their underlying microstructure, leading to an understanding of material behaviour, solid statics and hydrostatics and ultimately the appropriate use of different materials for engineering applications.