A water jet machine has essentially two components: a high intensity pump that pressurizes water to 40,000 — 90,000 PSI , and a cutting head assembly mounted on a frame that can move along the x-y-z direction over the material being cut. Pressurized water is forced through a tiny nozzle hole to create high energy density stream that can erode and tear the surface of materials to achieve a cutting affect. Pure water ca alone can cut plastics, foam, wood, resilient floor coverings, rubber and similar soft substances. In some cases, water is mixed with a garnet abrasive to cut harder materials such as metals, stone, ceramics, glass and dense composites.
