Water jet cutting is a cold cutting process where water is being compressed with a pressure of up to 60,000 psi and focused by a nozzle to form a jet having a diameter of 0.1 to 1mm. The cutting beam is accelerated up to a speed of 900 m/s. Related to air this corresponds to about triple sonic speed. By adding abrasives (e.g. garnet sand) the micro chip removal at the material is increasing – in this case the water jet only serves as accelerator of the solid particles.