A guillotine shear machine, also known as a guillotine cutter, is a machine that is used to cut sheet metal or plate steel. It typically consists of a blade that moves up and down, and a bed that the material is placed on. The blade moves down to cut the material, which is held in place by a clamp or hold-down device. Guillotine shears are commonly used in metalworking and manufacturing, and are capable of cutting materials with high precision and accuracy. They are also known as squaring shears and cutting shears.