Any machining process, whether performed by blades, lasers or water jets, is a volume reduction process. Usually, volume reduction processes are applied to materials in order to shape them.
Water jet cutting can be considered a machining process because it removes pieces from a material in order to change the shape of the material. Water jets can be used to drill, bore, cut and shape a variety of metals and plastics as well as some glass and ceramic materials. Water jet machining processes are generally limited to the processing of thin materials; metal sheets as well as plate glass and thin ceramics are among the most commonly water jet-machined products.
There are some exceptions to this, as some thicker, more complex products like mechanical gears are sometimes machined using water jets. The stronger and thicker the material, the more powerful the water jet must be in order to cut through it. Water jet machining equipment can produce water jets with pressures between 30,000 and 90,000 PSI, and some models can produce up to 120,000 PSI jets. Such high pressure water jet cutting systems are limited to use on very strong materials.
The strongest materials can sometimes require the use of abrasive media mixed into the water stream to make cutting easier. Because many machining processes involve precise abrasion or erosion, abrasive media are often used in machining processes to wear down surfaces effectively and precisely.
Computer numerical control (CNC) systems are used to control almost every water jet cutting system, which ensures the precise machining of every part. In addition to being more precise than many other machining methods, water jet cutting is a very efficient process. Once water and abrasives have been expelled from a water jet cutting system’s nozzle, they can be collected by a reclamation system and re-circulated. This greatly reduces the amount of water and abrasive materials necessary for machining.
Also, because water jet machining is an automated, cold-working process, it presents fewer occupational hazards to workers, who are usually a safe distance from the water jet while it operates. No hazardous fumes, sparks or dangerous flying debris that could threaten worker safety are produced during water jet machining, making it a safe and effective process.