WEBVTT - How can water cut through steel?

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<v Speaker 1>Welcome to Brainstuff from house stuffworks dot com, where smart

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<v Speaker 1>happens Him Marshall Brain with today's question, how can water

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<v Speaker 1>cut through steel? A water jet is a tool used

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<v Speaker 1>in machine shops to cut metal parts with a very

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<v Speaker 1>high pressure stream of water. As amazing as it sounds,

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<v Speaker 1>if you get water flowing fast enough, it can actually

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<v Speaker 1>cut metal. Think of a water jet is something with

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<v Speaker 1>about thirty times the pressure of the power washer wand

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<v Speaker 1>at your local car wash. Power washing a car washes

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<v Speaker 1>is an everyday example of a dirt film being cut

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<v Speaker 1>off the body, wheels, and tires of an automobile. The

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<v Speaker 1>key to cutting metal with water is to keep the

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<v Speaker 1>spray coherent. Water jets are able to cut because the

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<v Speaker 1>spray is channeled through a very narrow jeweled nozzle at

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<v Speaker 1>a very high pressure to keep the spray coherent. Unlike

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<v Speaker 1>metal cutters, a water jet never gets dull and it

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<v Speaker 1>can't overheat. Low pressure water jets were first used for

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<v Speaker 1>mining gold in California in eighteen fifty two. Steam and

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<v Speaker 1>hot water jets were used in the early nineteen hundreds

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<v Speaker 1>for cleaning. High pressure water jets were used for mining

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<v Speaker 1>in the nineteen sixties Abrasive water jets were first used

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<v Speaker 1>in industry in about nineteen eighty. In the past, only

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<v Speaker 1>one piece of metal could be cut at a time

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<v Speaker 1>with a saw or other metal cutting mechanical process. It

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<v Speaker 1>was time intensive and expensive. Computer controlled water jet and

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<v Speaker 1>abrasive jet cutting are used today an industry to cut

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<v Speaker 1>many soft and hard materials. The plain water abrasive mixture

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<v Speaker 1>leaves the nozzle more than nine miles per hour. The

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<v Speaker 1>latest machines can cut within two thousands of an inch,

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<v Speaker 1>and they have jet speeds around mock three. Water jets

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<v Speaker 1>can cut lots of different things, including marble, granite, metal, plastic, wood,

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<v Speaker 1>stainless steel, and aluminum. A water jet can cut a

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<v Speaker 1>sandwich of different materials up to four inches thick. This odorless,

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<v Speaker 1>dust free, and relatively heat free process can also cut

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<v Speaker 1>something as thin as five thousands of an inch. The

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<v Speaker 1>tiny jet stream permits the first cut to also be

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<v Speaker 1>the final finished surface of the piece. This single cutting

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<v Speaker 1>process saves material costs and machining costs. For example, the

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<v Speaker 1>engineer merely gives a gear drawing to the cutting shop

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<v Speaker 1>and gets back the finished gear very quickly. Water jets

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<v Speaker 1>cut softer materials while abrasive jets are used for harder materials.

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<v Speaker 1>The actual cutting is often done underwater to reduce splash

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<v Speaker 1>and noise. Faster feed rates are used to prevent the

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<v Speaker 1>jet from cutting all the way through the water. Pressure

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<v Speaker 1>is typically between twenty thousand and fifty five thousand pounds

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<v Speaker 1>per square inch. The water is forced through a tiny

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<v Speaker 1>hole in a jewel about one one of an inch

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<v Speaker 1>in diameter. For more on this and thousands of other topics,

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