Shear strength

In engineering, shear strength is the strength of a material or component against the type of yield or structural failure when 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 or construction of the component (e.g. beams, plates, or bolts).

applies where In general: ductile materials (e.g. aluminum) fail in shear, whereas brittle materials (e.g. cast iron) fail in tension (see: Tensile strength).

In real world applications, this equation only gives an approximation and the maximum shear stress would be higher.

Stress is not often equally distributed across a part so the shear strength would need to be higher to account for the estimate.

Mam Tor road destroyed by subsidence and shear , near Castleton , Derbyshire .
A shearing force is applied to the top of the rectangle while the bottom is held in place. The resulting shear stress, τ, deforms the rectangle into a parallelogram.
A shear force is applied to the top of the rectangle that deform the rectangle into a parallelogram. Having a higher shear modulus of elasticity increases the force needed to deform the rectangle.