Billet nicking is used to make a controlled break of a billet up to 14 cm (5-112 in.) thick. The billet is nicked to a depth of 12 to 18 mm (1/2 to 3/4 in.) by means of flame cutting or carbon arc cutting. Cold water is then poured into the nick in the hot metal, causing a crack, and the break is completed with force from a drop hammer, hydraulic press, or bulldozer.
