The mechanical properties of a metal with grain flow are anisotropic. The properties that involve a fracture or a crack (such as fatigue strength, impact resistance, tensile elongation) will be higher if the grain flow is along the longitudinal axis of the specimen being tested. This increase in mechanical properties is due to the greater resistance to crack propagation that occurs when the crack or fracture is occurring perpendicular to the grain flow. Grain flow can also affect the crystallographic orientation of the grains, leading to some anisotropy during plastic deformation (forging). This local anisotropy can cause localized flow and adiabatic shear bands in certain alloys.