This lecture covers the formation and characteristics of adiabatic shear bands, which are important precursors to fracture. It also introduces the concept of shockwaves and their impact on materials, including the differences between plastic waves and shock waves. The presentation includes experimental investigations of shear band formation in various materials, such as titanium alloys and steels, highlighting the microstructural changes within shear bands. The lecture delves into the metallurgical aspects of adiabatic shear bands, discussing the materials prone to shear band formation and the microstructural changes that occur. Additionally, constitutive modeling of shear bands and the effects of thermal softening are explored.