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saw

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Dictionary: saw1   () pronunciation
 
saw<sup>1</sup>
(Click to enlarge)
saw1
top to bottom: compass, backsaw, and crosscut saws
(Academy Artworks)
n.

Any of various tools, either hand-operated or power-driven, having a thin metal blade or disk with a sharp, usually toothed edge, used for cutting wood, metal, or other hard materials.


v., sawed, sawed or sawn (sôn), saw·ing, saws.

v.tr.
  1. To cut or divide with a saw.
  2. To produce or shape with a saw: sawed a hole in the board.
  3. To make back-and-forth motions through or on: a speaker who saws the air with his arms.
v.intr.
  1. To use a saw: sawing along the chalk line.
  2. To undergo cutting with a saw: Pine wood saws easily.

[Middle English sawe, from Old English sagu.]

sawer saw'er n.
saw2 () pronunciation
n.

A familiar saying, especially one that has become trite through repetition. See synonyms at saying.

[Middle English sawe, from Old English sagu, speech.]


saw3 () pronunciation
v.

Past tense of see1.


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How Products are Made: How is a saw made?
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Background

A saw is a hand tool with a toothed blade used to cut hard materials such as wood or bone. They are among the oldest known tools. Innovations made over thousands of years are still present in modern, mass-produced examples.

The first flint saws appeared during the early Paleolithic Era, between 60,000 and 10,000 B.C. Stone saws and composite saws made of stone bladelets or "microliths" set into a bone handle also were made during this time. The first metal blades were made possible by the discovery of copper about 4,000 years ago.

As the Iron Age began, the weaker copper and bronze were discarded and raked teeth were finally made possible. Eventually it became apparent that increasing the number of teeth in a saw increased the efficiency of its use. Small saws were used for carpentry, with the Asian style of pull-saws being specifically used by the Ancient Egyptians. Hieroglyphics discovered in Egyptian monuments record the Egyptians' use of the saw in their methods of furniture making. Adjustments in saw design were made according to a saw's intended application. For example, spaced teeth allowed the saw to double as a rake after the cutting stroke, removing sawdust from the developing "kern" or cut.

Saws continued to be improved as innovations in metallurgy were developed. Leonardo da Vinci invented a marble saw during the fifteenth century, and many developers in Europe and abroad took advantage of improvements in steel to create a better cutting edge. Throughout the seventeenth century, the strongest blades were still the narrowest. The bow saw—named for its structural similarity to the bow and arrow—continued to be popular because of this limitation. The popularity of the wooden frame saw among the early European settlers in America has been attributed to the scarcity of metal in the colonies at that time, as well as to the lack of wide-rolled steel.

With the advent of the Industrial Revolution, stronger, more durable saws were produced. For example, various forms of the circular saw were being made during the early eighteenth century, though the first patent in the United States was granted to Benjamin Cummins of New York in 1814. Today, a wide variety of manual and power saws are produced for consumer as well as commercial use.

Raw Materials

Tempered, high-grade tool steel, alloyed with certain other metals, is the main material used to manufacture the saw blade. Handles used to be made solely of wood, but modern tools can also be made with molded plastic.

Design

There are three major types of hand-held saws: the hacksaw, the bucksaw, and the iconically familiar crosscut or ripsaw.

The crosscut saw cuts across the grain, while the ripsaw cuts along the grain. The teeth of a saw are formulated differently to fulfill different needs. If the angle is too extreme, the teeth will catch on the wood. If the angle is too shallow, the teeth will be unable to cut at all. The teeth of a crosscut saw are angled more obtusely than those of a ripsaw, to slice into the wood grain without chiseling it. Conversely, the cutting edge of the ripsaw is set at right angles to the actual blade, so the teeth act like little chisels. A hardwood saw's teeth are optimally angled at 60 degrees, while softer woods must be cut with teeth set at a more acute angle, generally 45 degrees. Seasoned and green woods also call for differently shaped blades. A coarse saw has about five teeth per inch (two per cm), which is best when cutting green or soft wood. A fine saw, with at least eight teeth per inch (two per cm), can make smooth cuts in seasoned hardwood intended for show, or for more intricate constructions like dove-tailing.

The Manufacturing
Process

  1. A special type of steel alloyed with tungsten is produced and rolled into strips. The thickness of the strip sets the thickness of the finished blade and is gauged by the same instruments used to measure wires.
  2. The blades are then stamped out of the alloyed steel using stamping machines. The overall shape of the handsaw blade narrows from handle to tip. The best saws have a "crown" or curved cutting edge, rather than a straight one, so fewer teeth are in contact with the surface of the wood at any given time while the saw is in motion. Most inexpensive handsaws are of a uniform thickness.
  3. The blade is then processed according to standards for optimal use. Depending on the type of saw, different techniques may be applied. The crosscut saw, for instance, is bevel filed. The back of a handsaw is ground thinner than the toothed edge to reduce friction during use. Handsaws are generally taper ground.
  4. The "set" or adjustment of the blade's teeth is crucial to the saw's effectiveness, so teeth are measured with a gauge made of plate steel that analyses three teeth at a time. Then, they are cut and bent in altemating directions. Too much angling away from each other, however, results in a saw that does not cut properly.
  5. Hardening comes next. The classic technique used for centuries includes hammering the blade to render it "tensioned," so it displays the best combination of stiffness and flexibility. Many variations are possible. Today, professional hacksaws are hardened throughout, while those intended for home use have only their teeth hardened.
  6. A coating of rust protection is sprayed on the hardened saw blade.
  7. Finally, the blades are fastened to separately made, injection-molded handles.

Quality Control

The American National Standard is intended to regulate the set of blades for safety as well as optimal use, since a badly made saw can be a hazard. Hacksaw blades with 24-32 teeth per inch (10-13 teeth per cm) must be set wavy. Other types of saws require a "raker set" in which every third tooth is left unset. The composite of the metal used is also regulated. A standard steel blade, in order to be called that, cannot be more than 1.25% alloy. For industrial and high-power saws, a high-speed steel blade must be able to withstand a temperature up to 1,000°F (537.78°C).

The Future

Thanks to such user-friendly optimization software as computer aided design (CAD), refinements are being experimented with that may retard the effects of repetitive motion on the handsaw user. "Cumulative Trauma Disorders," as they are known in the field, must be counteracted by ergonomic research. Goals include spreading the impact of using a saw over a larger area, reducing the need for sharp corrective movements, and improving the fit of the handle to avoid uncomfortable hand and arm positions. Volunteer test groups are used to gauge consumer needs and professional users test prototypes of products under development.

The same approach is being made towards improving both large and small scale power tools. Computer-aided manufacturing (CAM), computer-integrated manufacturing (CIM), and numerical control (NC) techniques allow saw manufacturers to cut waste and improve efficiency. Circle saws in the lumber industry have been reinvented with the help of finite element analysis. The Saw Paw Corporation of Pennsylvania holds patents on a recyclable, one-piece carbide saw shank and bit. The streamlined design is geared towards improving efficiency, while lengthening life expectancy, in order to lower the long-term cost of use.

Where to Learn More

Books

Armentrout, Patricia and David. The Saw. Rourke Publishers Group, 1995.

Disston, Henry. The Saw In History. H. Disston & Sons, Inc., 1922.

Goodman, W. L. The History of Woodworking Tools. G. Bell and Sons, Ltd., 1964.

Saws. Miller Freeman Publishers, 1990.

Periodicals

Christianson, Rich. "Computer Advances Drive Panel Saws Forward." Wood & Wood Products, October 1996, pp. 83-90.

[Article by: Jennifer Swift Kramer]


 
Thesaurus: saw
Top

noun

    A usually pithy and familiar statement expressing an observation or principle generally accepted as wise or true: adage, aphorism, byword, maxim, motto, proverb, saying. See words.

 

n

A cutting blade with a toothed edge used to cut material too hard to slice with a knife.

 

Tool for cutting solid materials to prescribed lengths or shapes. Most saws take the form of a thin metal strip with teeth on one edge or a thin metal disk with teeth on the edge. The teeth are usually set to alternate sides so that the kerf (groove) cut by the saw is wider than the thickness of the saw; the saw blade can thus move freely in the groove without binding. Thin-strip saws are used in various ways in both hand and machine operations; circular, or disk, saws are always machine powered (see sawing machine, machine tool).

For more information on saw, visit Britannica.com.

 
Architecture: saw
Top

A cutting tool having a thin, flat metal blade, band, or stiff plate with cutting teeth along the edge; worked either by a reciprocating motion (as in a handsaw) or by a continuous motion (as in a band saw).


 

Multi-toothed cutting instrument.

  • chain s. — see pearson saw.
  • Stryker s. — see stryker saw.
  • surgical s. — modeled on carpentry tools but made of sterilizable materials; used for cutting cartilage and bone.
  • wire s. — see wire saw, gigli wire saw.
 
A cynical view of the world by Ambrose Bierce


n.

A trite popular saying, or proverb. (Figurative and colloquial.) So called because it makes its way into a wooden head. Following are examples of old saws fitted with new teeth.

        A penny saved is a penny to squander.
    
        A man is known by the company that he organizes.
    
        A bad workman quarrels with the man who calls him that.
    
        A bird in the hand is worth what it will bring.
    
        Better late than before anybody has invited you.
    
        Example is better than following it.
    
        Half a loaf is better than a whole one if there is much else.
    
        Think twice before you speak to a friend in need.
    
        What is worth doing is worth the trouble of asking somebody to 
    do it.
    
        Least said is soonest disavowed.
    
        He laughs best who laughs least.
    
        Speak of the Devil and he will hear about it.
    
        Of two evils choose to be the least.
    
        Strike while your employer has a big contract.
    
        Where there's a will there's a won't.


 
Word Tutor: saw
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pronunciation

IN BRIEF: A power tool for cutting wood.

pronunciation My dad let me use the saw to cut the wood for the doghouse.

 
Wikipedia: Saw
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Saw
A crosscut hand saw about 620 mm long
Classification Cutting
Types Hand saw
Back saw
Bow saw
Circular saw
Reciprocating saw
Band saw
Related Milling cutter

A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials. The cutting edge of a saw is either a serrated blade or an abrasive. A saw may be worked by hand, or powered by steam, water, electric or other power.

In a modern serrated saw, each tooth is bent to a precise angle called its set. The set of the teeth is determined by the kind of cut the saw is intended to make. For example, a rip saw has a tooth set that is similar to the angle used on a chisel. The idea is to have the teeth rip or tear the material apart. Some teeth are usually splayed slightly to each side of the blade so that the cut width (kerf) is wider than the blade itself and the blade does not bind in the cut. The kerf of the blade is adjusted with a tool called a saw tooth setter.

An abrasive saw uses an abrasive disc or band for cutting, rather than a serrated blade.

According to Chinese tradition, the saw was invented by Lu Ban.[citation needed] In Greek mythology, Talos, the nephew of Daedalos, invented the saw. In fact, saws date back to prehistory, and likely evolved from Neolithic tools or bone tools. The early ancestors of man, in the Pleistocene era, likely first used a jaw bone of bovid animals as a saw.

Contents

Types of saw blades and the cuts they make

Blade teeth are of two general types: Tool steel or carbide. Carbide is harder and holds a sharp edge much longer.

Band Saw Blade
A straight blade welded into a circle. Used mainly at sawmills & steel service centers. Preferred over circular saws due to less waste.
Crosscut
In woodworking, a cut made at (or near) a right angle to the direction of the grain of the workpiece. A crosscut saw is used to make this type of cut.
Rip cut
In woodworking, a cut made parallel to the direction of the grain of the workpiece. A rip saw is used to make this type of cut.
Plytooth
A circular saw blade with many small teeth designed for cutting plywood with minimal splintering.
Dado blade
A special type of circular saw blade used for making wide grooved cuts in wood so the edge of another piece of wood will fit into the groove to make a joint. Dado blades can make different width grooves by addition or removal of chipper blades of various widths between the outer sadaio blades. This first type is called a stacked dado blade. There is another type of dado blade capable of cutting variable width groove. Das. An adjustable dado utilizes a movable locking cam mechanism which causes the blade to wobble sideways more or less. This allows continuously variable groove width from the lower to upper design limits of the dado.

Materials used for saws

There are several materials used in saws, with each of its own specifications.

Brass
Mostly used in back saws because of its low price, its flow characteristics that make the material relatively easy to cast, and unlike other types of saw, the forces that take place in back saws are relatively low because of the pulling motion used.
Steel
Used in almost every existing kind of saw. Because steel is cheap, easy to shape, and very strong, it has the right properties for most kind of saws.
Diamond
Used only in saws for the really heavy cutting. It is very expensive and comes in two shapes: ropes and circular saws. Mostly used for cutting concrete and other materials with rock-like structures or in softer materials, such as wood, where the precision and high volume of work justifies the expense of diamond-edged cutting tools. Diamond saws are made by combining powder metal with diamond crystals, which are then heated and pressed into a molding to form the diamond segments.

Uses

  • Saws are most commonly used for cutting hard materials. They are used extensively in forestry, construction, demolition, medicine, and hunting.
  • Some saws are used as instruments to make music.
  • Chainsaw carving is a flourishing modern art form. Special saws have been developed for this purpose.

Saws in nature

  • Teeth or similar mouthparts are used by many creatures to cut their food.
  • Sawgrass is an example of a plant that use serrated leaves as a defense mechanism.
  • The sawfish has a sawlike snout that is, however, not used as a saw.

See also

External links

References


 
Translations: Saw
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Dansk (Danish)
1.
n. - sav
v. tr. - save, save brænde
v. intr. - fægte med armene

2.
n. - mundheld, sentens

Nederlands (Dutch)
zagen, zaag, gezegde, cliché

Français (French)
1.
n. - scie
v. tr. - scier
v. intr. - scier

idioms:

  • saw off    scier (un canon d'un fusil)

2.
n. - adage

Deutsch (German)
1.
n. - Säge
v. - sägen, sah

idioms:

  • saw off    einen Ast absägen

2.
n. - Sprichwort

Ελληνική (Greek)
n. - πριόνι, απόφθεγμα
v. - πριονίζω, κόβω με πριόνι, (μτφ.) κουτσουρεύω

Italiano (Italian)
segare, detto, sega

Português (Portuguese)
n. - serra (f), ditado (m)
v. - serrar

Русский (Russian)
пила, полотно пилы, изречение, афоризм, пословица, распиливать, пиликать

Español (Spanish)
1.
n. - sierra, serrucho
v. tr. - serrar, aserrar
v. intr. - serrar, aserrar, cortar, serrarse, aserrarse, tocar el violín

idioms:

  • saw off    llegar un compromiso mediante concesiones mutuas

2.
n. - dicho, refrán, proverbio, máxima

Svenska (Swedish)
n. - såg, ordstäv, talesätt, visdomsord
v. - såga, vifta med armarna

中文(简体)(Chinese (Simplified))
1. 锯子, 锯齿状部, 锯条, 锯, 锯成, 锯开, 拉锯般来回移动, 用锯, 拉锯

2. 格言, 谚语

中文(繁體)(Chinese (Traditional))
1.
n. - 鋸子, 鋸齒狀部, 鋸條
v. tr. - 鋸, 鋸成, 鋸開, 拉鋸般來回移動
v. intr. - 用鋸, 拉鋸, 鋸開

2.
n. - 格言, 諺語

한국어 (Korean)
1.
n. - 톱, 톱니 모양의 부분
v. tr. - 톱으로 켜다, (책의 등 부분에) 칼자국을 내다
v. intr. - 톱질하다, 톱으로 켜지다, 현악기를 연주하다

2.
n. - 속담, 격언, 10 달러

日本語 (Japanese)
n. - のこ, 鋸, 鋸歯状部, ことわざ, 格言
v. - 動かす, のこでひく, 木をひく, のこでひける, のこぎりでひく

العربيه (Arabic)
‏(الاسم) منشار (فعل) ينشر ألخشب‏

עברית (Hebrew)
n. - ‮מסור, משור‬
v. tr. - ‮ניסר‬
v. intr. - ‮הניע כמסור‬
n. - ‮פתגם, מימרה‬


 
Best of the Web: Kerf
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Some good "saw" pages on the web:


American Sign Language
commtechlab.msu.edu
 
 
 
Redirected from "Kerf"

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saw kerf
drunken saw, wobble saw
segment saw

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