High Quality Content by WIKIPEDIA articles! Shear strength in engineering is a term used to describe the strength of a material or component against the type of yield or structural failure where the material or component fails in shear. In structural and mechanical engineering the shear strength of a component is important for designing the dimensions and materials to be used for the manufacture/construction of the component (e.g. beams, plates, or bolts) In a reinforced concrete beam, the main purpose of stirrups is to increase the shear strength. In general: ductile materials fail in shear (ex. aluminum), whereas brittle materials (ex. cast iron) fail in tension.