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Speaker 1: Welcome to Brainstuff from house stuffworks dot com, where smart

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Speaker 1: happens Him Marshall Brain with today's question, how can water

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Speaker 1: cut through steel? A water jet is a tool used

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Speaker 1: in machine shops to cut metal parts with a very

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Speaker 1: high pressure stream of water. As amazing as it sounds,

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Speaker 1: if you get water flowing fast enough, it can actually

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Speaker 1: cut metal. Think of a water jet is something with

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Speaker 1: about thirty times the pressure of the power washer wand

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Speaker 1: at your local car wash. Power washing a car washes

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Speaker 1: is an everyday example of a dirt film being cut

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Speaker 1: off the body, wheels, and tires of an automobile. The

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Speaker 1: key to cutting metal with water is to keep the

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Speaker 1: spray coherent. Water jets are able to cut because the

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Speaker 1: spray is channeled through a very narrow jeweled nozzle at

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Speaker 1: a very high pressure to keep the spray coherent. Unlike

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Speaker 1: metal cutters, a water jet never gets dull and it

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Speaker 1: can't overheat. Low pressure water jets were first used for

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Speaker 1: mining gold in California in eighteen fifty two. Steam and

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Speaker 1: hot water jets were used in the early nineteen hundreds

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Speaker 1: for cleaning. High pressure water jets were used for mining

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Speaker 1: in the nineteen sixties Abrasive water jets were first used

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Speaker 1: in industry in about nineteen eighty. In the past, only

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Speaker 1: one piece of metal could be cut at a time

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Speaker 1: with a saw or other metal cutting mechanical process. It

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Speaker 1: was time intensive and expensive. Computer controlled water jet and

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Speaker 1: abrasive jet cutting are used today an industry to cut

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Speaker 1: many soft and hard materials. The plain water abrasive mixture

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Speaker 1: leaves the nozzle more than nine miles per hour. The

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Speaker 1: latest machines can cut within two thousands of an inch,

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Speaker 1: and they have jet speeds around mock three. Water jets

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Speaker 1: can cut lots of different things, including marble, granite, metal, plastic, wood,

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Speaker 1: stainless steel, and aluminum. A water jet can cut a

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Speaker 1: sandwich of different materials up to four inches thick. This odorless,

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Speaker 1: dust free, and relatively heat free process can also cut

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Speaker 1: something as thin as five thousands of an inch. The

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Speaker 1: tiny jet stream permits the first cut to also be

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Speaker 1: the final finished surface of the piece. This single cutting

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Speaker 1: process saves material costs and machining costs. For example, the

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Speaker 1: engineer merely gives a gear drawing to the cutting shop

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Speaker 1: and gets back the finished gear very quickly. Water jets

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Speaker 1: cut softer materials while abrasive jets are used for harder materials.

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Speaker 1: The actual cutting is often done underwater to reduce splash

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Speaker 1: and noise. Faster feed rates are used to prevent the

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Speaker 1: jet from cutting all the way through the water. Pressure

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Speaker 1: is typically between twenty thousand and fifty five thousand pounds

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Speaker 1: per square inch. The water is forced through a tiny

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Speaker 1: hole in a jewel about one one of an inch

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Speaker 1: in diameter. For more on this and thousands of other topics,

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Speaker 1: visit how stuff works dot com, and don't forget to

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Speaker 1: check out the brain stuff blog on the how stuff

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