Waterjet cutter. Waterjet cutter being used to cut through a metal part. The cutter cuts with a jet of water mixed with abrasives (such as silica sand or garnet) which is fired out of a carbide nozzle (centre). Water is first compressed to 12 percent of its volume. It then enters a chamber where it is mixed with the abrasives. It will then exit the nozzle at speeds of up to 900 metres per second. Abrasive water cutting is a high precision process that does not produce heat that can degrade metallurgical properties. The sparks at lower centre are cased by the friction between the abrasive particles and the metal.