Water Jet Metal Cutting
As amazing as it sounds, if you get water flowing fast enough it can actually cut metal. Waterjet cutting is one of the most versatile cutting processes around. Well suited for high-performance metal cutting, waterjet technology, when used with an abrasive additive, creates a clean, burr-free cut that does not require secondary finishing and does not leave a heat-affected zone. Nearly every type of cut is possible, from rapid hole drilling to detailed cuts for automotive applications. Waterjet cutting systems are also less expensive than laser-cutting systems, making them a solid choice for metal and steel cutting in the fabrication industry.
Photo courtesy of OMAX
Waterjets are able to cut because the spray is channeled through a very narrow jeweled nozzle at a very high pressure to keep the spray coherent. Unlike metal cutters, a waterjet never gets dull and it cannot overheat. The water pressure is typically between 20,000 and 55,000 pounds per square inch (PSI). The water is forced through a 0.010" to 0.015" in diameter orifice (hole) in a jewel.
In the past, only one piece of metal could be cut at a time with a saw or other metal cutting mechanical process. It was time intensive and expensive. Computer-controlled waterjet and abrasivejet cutting are used today in industry to cut many soft and hard materials. The plain water-abrasive mixture leaves the nozzle at more than 900 mph. The latest machines can cut to within two thousandths of an inch, and have jet speeds around Mach 3.
A water jet can cut a "sandwich" of different materials up to four inches thick. This odorless, dust-free and relatively heat-free process can also cut something as thin as five thousandths of an inch. The tiny jet stream also permits the first cut to be the final finished surface. This single cutting process saves material costs and machining costs.