Serration

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The serrated edges of tiger shark teeth Tiger shark serration.jpg
The serrated edges of tiger shark teeth
A hunting knife with a serrated back edge Knife (3263343357).png
A hunting knife with a serrated back edge
Serrated leaves of the stinging nettle, Urtica dioica Ortie.jpg
Serrated leaves of the stinging nettle, Urtica dioica
A Meyerco bolt action knife, designed by Blackie Collins, and featuring a partially serrated blade. Meyerco bolt action.jpg
A Meyerco bolt action knife, designed by Blackie Collins, and featuring a partially serrated blade.

Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied pressure at each point of contact is greater, and the points of contact are at a sharper angle to the material being cut. This causes a cutting action that involves many small splits in the surface of the material being cut, which cumulatively serve to cut the material along the line of the blade. [1]

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Serration in nature

In nature, serration is commonly seen in the cutting edge on the teeth of some species, usually sharks. However, it also appears on non-cutting surfaces, for example, in botany where a toothed leaf margin or other plant part, such as the edge of a carnation petal, is described as being serrated. A serrated leaf edge may reduce the force of wind and other natural elements. [2] Probably[ clarification needed ] the largest serrations on Earth occur on the skylines of mountains (the Spanish word sierra, as in the Sierra Nevada, means a saw). These occur due to the uneven action of landform edges pushing rock upwards, and the uneven action of erosion.[ citation needed ]

Human uses of serration have copied, and gone beyond, those found in nature. For example, the teeth on a saw or other serrated blade serve a similar cutting or scraping purpose as the serration of an animal tooth. Tailors use pinking shears to cut cloth with a serrated edge, which, somewhat counterintuitively, reduces fraying by reducing the average length of a thread that may be pulled from the edge. [3] A type of serration is also found in airframe shapes used in certain stealth aircraft, which use the jaggedness of the serrated edge to deflect radar signals from seams and edges where a straight, non-serrated edge would reflect radar signals to the source. Screw threads show serration in profile, although they are usually shown in abbreviated or symbolic fashion on mechanical drawings to save time and ink. Brogue shoes are made with serrated edges on the leather pieces, for no known purpose at all other than style. The step clamp and step block assembly in metalworking adopt serration for the purpose of applying clamping pressure from an adjustable position.

Serration in blades

Humans have used serrated blades since the Mesolithic era, when prehistoric humans made these from flint. [4] A serrated blade has a toothlike rather than a plain edge, and is used on saws and on some knives and scissors. It is also known as a dentated, sawtooth, or toothed blade. Many such blades are scalloped, [5] having edges cut with curved notches, common on wood saws and bread knives.

With kitchen knives, the finer serrated edge is found typically on paring and cheese knives, particularly for slicing harder cheeses like cheddar or Wensleydale. The wider scalloped-edge serrations are found on practically all bread knives and typically on fruit knives. These serrated knives are better able to cut through a firmer or tougher outer crust or skin without crushing the softer and more delicate inner crumb or flesh.

Serrations give the blade's cutting edge less contact area than a smooth blade, which increases the applied pressure at each point of contact, and the points of contact are at a sharper angle to the material being cut. This causes a cutting action that involves many small splits in the surface of the material being cut, which cumulatively serve to cut the material along the line of the blade. [6]

Cuts made with a serrated blade are typically less smooth and precise than cuts made with a smooth blade. Serrated edges can be difficult to sharpen using a whetstone or rotary sharpener intended for straight edges but can be sharpened with ceramic or diamond coated rods. Further, they tend to stay sharper longer than similar straight edges. A serrated blade has a faster cut, but a plain edge has a cleaner cut. Some prefer a serrated blade on a pocket knife [7] or on an emergency rescue knife, especially with the latter for its increased ability to cut through cords, ropes, and safety belts.

Types of blade serration

See also

Related Research Articles

<span class="mw-page-title-main">Knife</span> Tool or weapon with a cutting edge or blade

A knife is a tool or weapon with a cutting edge or blade, usually attached to a handle or hilt. One of the earliest tools used by humanity, knives appeared at least 2.5 million years ago, as evidenced by the Oldowan tools. Originally made of wood, bone, and stone, over the centuries, in step with improvements in both metallurgy and manufacturing, knife blades have been made from copper, bronze, iron, steel, ceramic, and titanium. Most modern knives have either fixed or folding blades; blade patterns and styles vary by maker and country of origin.

<span class="mw-page-title-main">Hand saw</span> Wood cutting tool

In woodworking and carpentry, hand saws, also known as "panel saws", are used to cut pieces of wood into different shapes. This is usually done in order to join the pieces together and carve a wooden object. They usually operate by having a series of sharp points of some substance that is harder than the wood being cut. The hand saw is a bit like a tenon saw, but with one flat, sharp edge.

<span class="mw-page-title-main">Blade</span> Sharp cutting part of a weapon or tool

A blade is the sharp, cutting portion of a tool, weapon, or machine, specifically designed to puncture, chop, slice, or scrape surfaces or materials. Blades are typically made from materials that are harder than those they are intended to cut. This includes early examples made from flaked stones like flint or obsidian, evolving through the ages into metal forms like copper, bronze, and iron, and culminating in modern versions made from steel or ceramics. Serving as one of humanity's oldest tools, blades continue to have wide-ranging applications, including in combat, cooking, and various other everyday and specialized tasks.

<span class="mw-page-title-main">Japanese kitchen knife</span> Type of knife used for food preparation

A Japanese kitchen knife is a type of kitchen knife used for food preparation. These knives come in many different varieties and are often made using traditional Japanese blacksmithing techniques. They can be made from stainless steel, or hagane, which is the same kind of steel used to make Japanese swords. Most knives are referred to as hōchō or the variation -bōchō in compound words but can have other names including -kiri. There are four general categories used to distinguish the Japanese knife designs: handle ; blade grind ; steel ; and construction.

<i>Yanagi ba</i> Japanese knife for preparing sushi and sashimi

Yanagi-ba-bōchō, Yanagiba, or yanagi, is a long and thin knife used in the Japanese cuisine. It is the typical example of the sashimibōchō used to slice fish for sashimi and nigirizushi.

<i>Usuba bōchō</i> Professional Japanese chefs knife

Usuba bōchō is the traditional vegetable knife for the professional Japanese chef. Like other Japanese professional knives, usuba are chisel ground, and have a single bevel on the front side, and have a hollow ground urasuki on the back side. Usuba characteristically have a straight edge, with little or no curve, and are wide or tall blade in height, to allow knuckle clearance when chopping on a cutting board. A usubas is relatively thin compared to other knives, required for cutting through firm vegetables without cracking them. Due to its height and straight edge, they are also used for specialized cuts such as katsuramuki, shaving a vegetable cylinder into a thin sheet.

<span class="mw-page-title-main">File (tool)</span> Tool used to remove fine amounts of material

A file is a tool used to remove fine amounts of material from a workpiece. It is common in woodworking, metalworking, and other similar trade and hobby tasks. Most are hand tools, made of a case hardened steel bar of rectangular, square, triangular, or round cross-section, with one or more surfaces cut with sharp, generally parallel teeth. A narrow, pointed tang is common at one end, to which a handle may be fitted.

<span class="mw-page-title-main">Grind</span> Cross sectional shape of a blade in a plane normal to its edge

A blade's grind is its cross-sectional shape in a plane normal to the edge. Grind differs from blade profile, which is the blade's cross-sectional shape in the plane containing the blade's edge and the centre contour of the blade's back. The grind of a blade should not be confused with the bevel forming the sharpened edge; it more usually describes the overall cross-section of the blade, not inclusive of the beveled cutting edge which is typically of a different, less acute angle as the bevel ground onto the blade to give it a cross-sectional shape. For example, the famous Buck 110 hunting knife has a "hollow ground" blade, with concave blade faces, but the cutting edge itself is a simple, flat-ground bevel of lesser angle. It would be difficult, if not impossible, to put a "hollow grind" onto the actual cutting edge of the blade itself, which is a very narrow and small bevel.

<span class="mw-page-title-main">Sickle</span> Single-handed agricultural tool

A sickle, bagging hook, reaping-hook or grasshook is a single-handed agricultural tool designed with variously curved blades and typically used for harvesting or reaping grain crops, or cutting succulent forage chiefly for feeding livestock. Falx was a synonym, but was later used to mean any of a number of tools that had a curved blade that was sharp on the inside edge.

<span class="mw-page-title-main">Bandsaw</span> Power saw with a long, sharp blade

A bandsaw is a power saw with a long, sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material. They are used principally in woodworking, metalworking, and lumbering, but may cut a variety of materials. Advantages include uniform cutting action as a result of an evenly distributed tooth load, and the ability to cut irregular or curved shapes like a jigsaw. The minimum radius of a curve is determined by the width of the band and its kerf. Most bandsaws have two wheels rotating in the same plane, one of which is powered, although some may have three or four to distribute the load. The blade itself can come in a variety of sizes and tooth pitches, which enables the machine to be highly versatile and able to cut a wide variety of materials including wood, metal and plastic. Band saw is recommended for use in cutting metal as it produces much less toxic fumes and particulates when compared with angle grinder and reciprocating saw.

<span class="mw-page-title-main">Bread knife</span> Serrated knife used for cutting bread

Bread knives are used for cutting bread and are one of many kitchen knives used by cooks. The serrated blades of bread knives are able to cut soft bread without crushing it.

<span class="mw-page-title-main">Kitchen knife</span> Knives intended for use in the process of preparing food

A kitchen knife is any knife that is intended to be used in food preparation. While much of this work can be accomplished with a few general-purpose knives — notably a large chef's knife and a smaller serrated blade utility knife — there are also many specialized knives that are designed for specific tasks such as a tough cleaver, a small paring knife, and a bread knife. Kitchen knives can be made from several different materials, though the commonest is a hardened steel blade with a wooden handle.

<span class="mw-page-title-main">Chef's knife</span> Type of kitchen knife

In cooking, a chef's knife, also known as a cook's knife, is a cutting tool used in food preparation. The chef's knife was originally designed primarily to slice and disjoint large cuts of beef and mutton. Today it is the primary general utility knife for most Western cooks.

<span class="mw-page-title-main">Sharpening</span> Creating or refining the edge of a cutting tool

Sharpening is the process of creating or refining the edge joining two non-coplanar faces into a converging apex, thereby creating an edge of appropriate shape on a tool or implement designed for cutting. Sharpening is done by removing material on an implement with an abrasive substance harder than the material of the implement, followed sometimes by processes to polish/hone the sharp surface to increase smoothness.

<span class="mw-page-title-main">Knife sharpening</span> Process of grinding a knife against a hard surface

Knife sharpening is the process of making a knife or similar tool sharp by grinding against a hard, rough surface, typically a stone, or a flexible surface with hard particles, such as sandpaper. Additionally, a leather razor strop, or strop, is often used to straighten and polish an edge.

This glossary of woodworking lists a number of specialized terms and concepts used in woodworking, carpentry, and related disciplines.

<span class="mw-page-title-main">Tomato knife</span> Kitchen utensil

A tomato knife is a small serrated kitchen knife designed to slice through tomatoes. The serrated edge allows the knife to penetrate the tomatoes’ skin quickly and with a minimum of pressure without crushing the flesh. Many tomato knives have forked tips that allow the user to lift and move the tomato slices after they have been cut.

<span class="mw-page-title-main">Boot and shoe clicker</span>

A boot and shoe clicker is the person who cuts the uppers for boots or shoes from a skin of leather or piece of man-made material. This includes all components of the upper, including linings, facings, stiffeners, reinforcements for eyelets and zip-protectors.

<span class="mw-page-title-main">Steak knife</span> Sharp table knife used for cutting steak

A steak knife is a sharp table knife designed to efficiently and effectively cut steak. This type of knife comes in a variety of styles and sizes; however, the design often used in a steakhouse typically features a partially serrated blade and wood handle.

<span class="mw-page-title-main">Sharpness (cutting)</span> Ability to cut through materials

Sharpness refers to the ability of a blade, point, or cutting implement to cut through materials with minimal force, and can more specifically be defined as the capacity of a surface to initiate the cut. Sharpness depends on factors such as the edge angle, edge width, and the fineness of the cutting edge, and is aided by material hardness. This quality is found in a variety of naturally occurring forms, including certain kinds of rock, in plant thorns and spines, and in animal teeth, claws, horns, and other structures serving various purposes. Sharpness is also a critical attribute for man-made tools ranging from kitchen knives and scissors to industrial cutting equipment, as it allows the user of a sharp implement to efficiently penetrate surfaces, or neatly divide other materials into smaller portions as needed.

References

  1. Alloway, David (2000). Desert Survival Skills. University of Texas Press. p. 38. ISBN   978-0-292-70492-3.
  2. Hemsley, Alan R.; Poole, Imogen (2005). The Evolution of Plant Physiology. p. 220.
  3. Audin, Heather (2015). "2". Making Victorian Costumes for Women.
  4. Archaeology, Cotswold (March 8, 2024). "Flint Serrated Tool".
  5. "Williams Sonoma" . Retrieved 13 January 2023.
  6. Alloway, David (2000). Desert Survival Skills. University of Texas Press. p. 38. ISBN   978-0-292-70492-3.
  7. Hertzmann, Peter (2007). Knife Skills Illustrated: A User's Manual. W. W. Norton & Company. p. 17. ISBN   978-0-393-06178-9.