Cutting

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Different types of scissors - sewing (left), paper (middle), kitchen (right) Scissors.jpg
Different types of scissors – sewing (left), paper (middle), kitchen (right)
A glass cutter, showing hardened steel cutting wheel (far left), notches for snapping, and ball (on end of handle) for tapping Glass cutter.jpg
A glass cutter, showing hardened steel cutting wheel (far left), notches for snapping, and ball (on end of handle) for tapping

Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force.

Contents

Implements commonly used for cutting are the knife and saw, or in medicine and science the scalpel and microtome. However, any sufficiently sharp object is capable of cutting if it has a hardness sufficiently larger than the object being cut, and if it is applied with sufficient force. Even liquids can be used to cut things when applied with sufficient force (see water jet cutter).

Cutting is a compressive and shearing phenomenon, and occurs only when the total stress generated by the cutting implement exceeds the ultimate strength of the material of the object being cut. The simplest applicable equation is:

or

The stress generated by a cutting implement is directly proportional to the force with which it is applied, and inversely proportional to the area of contact. [1] Hence, the smaller the area (i.e., the sharper the cutting implement), the less force is needed to cut something. It is generally seen that cutting edges are thinner for cutting soft materials and thicker for harder materials. This progression is seen from kitchen knife, to cleaver, to axe, and is a balance between the easy cutting action of a thin blade vs strength and edge durability of a thicker blade.

Metal cutting

Cutting has been at the core of manufacturing throughout history. For metals many methods are used and can be grouped by the physical phenomenon used. It is the process of producing a work piece by removing unwanted material from a block of metal, in the form of chips.

Every method has its limitations in accuracy, cost, and effect on the material. For example, heat may damage the quality of heat treated alloys, and laser cutting is less suitable for highly reflective materials such as aluminum. [2] Laser cutting sheet metal produces flat parts and etches and engraves parts from complex or simple designs. It is used over other cutting options for its quick process and customizable abilities. [3]

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">Metalworking</span> Process of making items from metal

Metalworking is the process of shaping and reshaping metals to create useful objects, parts, assemblies, and large scale structures. As a term it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale: from huge ships, buildings, and bridges down to precise engine parts and delicate jewelry.

In physics and materials science, elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed. Solid objects will deform when adequate loads are applied to them; if the material is elastic, the object will return to its initial shape and size after removal. This is in contrast to plasticity, in which the object fails to do so and instead remains in its deformed state.

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

A blade is the portion of a tool, weapon, or machine with an edge that is designed to puncture, chop, slice or scrape surfaces or materials. Blades are typically made from materials that are harder than those they are to be used on. Historically, humans have made blades from flaking stones such as flint or obsidian, and from various metal such as copper, bronze, and iron. Modern blades are often made of steel or ceramic. Blades are one of humanity's oldest tools, and continue to be used for combat, food preparation, and other purposes.

An abrasive is a material, often a mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away by friction. While finishing a material often means polishing it to gain a smooth, reflective surface, the process can also involve roughening as in satin, matte or beaded finishes. In short, the ceramics which are used to cut, grind and polish other softer materials are known as abrasives.

<span class="mw-page-title-main">Machining</span> Material-removal process; manufacturing process

Machining is a manufacturing process whereby a desired shape or part is achieved by the controlled removal of material from a larger piece of raw material by cutting; it is most often performed with metal material. These processes are collectively called subtractive manufacturing, which utilizes machine tools, in contrast to additive manufacturing, which uses controlled addition of material.

<span class="mw-page-title-main">Shear stress</span> Component of stress coplanar with a material cross section

Shear stress is the component of stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross section. Normal stress, on the other hand, arises from the force vector component perpendicular to the material cross section on which it acts.

<span class="mw-page-title-main">Laser cutting</span> Technology that uses a laser to cut materials

Laser cutting is a technology that uses a laser to vaporize materials, resulting in a cut edge. While typically used for industrial manufacturing applications, it is now used by schools, small businesses, architecture, and hobbyists. Laser cutting works by directing the output of a high-power laser most commonly through optics. The laser optics and CNC are used to direct the laser beam to the material. A commercial laser for cutting materials uses a motion control system to follow a CNC or G-code of the pattern to be cut onto the material. The focused laser beam is directed at the material, which then either melts, burns, vaporizes away, or is blown away by a jet of gas, leaving an edge with a high-quality surface finish.

<span class="mw-page-title-main">Metal fabrication</span> Creation of metal structures

Metal fabrication is the creation of metal structures by cutting, bending and assembling processes. It is a value-added process involving the creation of machines, parts, and structures from various raw materials.

<span class="mw-page-title-main">Electrochemical machining</span> Process for shaping conductive metals

Electrochemical machining (ECM) is a method of removing metal by an electrochemical process. It is normally used for mass production and for working extremely hard materials, or materials that are difficult to machine using conventional methods. Its use is limited to electrically conductive materials. ECM can cut small or odd-shaped angles, intricate contours or cavities in hard and exotic metals, such as titanium aluminides, Inconel, Waspaloy, and high nickel, cobalt, and rhenium alloys. Both external and internal geometries can be machined.

<span class="mw-page-title-main">Sheet metal</span> Metal formed into thin, flat pieces

Sheet metal is metal formed into thin, flat pieces, usually by an industrial process.

A wedge is a triangular shaped tool, a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converting a force applied to its blunt end into forces perpendicular (normal) to its inclined surfaces. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width. Although a short wedge with a wide angle may do a job faster, it requires more force than a long wedge with a narrow angle.

This article is a list of terms commonly used in the practice of metalworking – the science, art, industry, and craft of shaping metal.

<span class="mw-page-title-main">Roll slitting</span> Shearing operation

Roll slitting is a shearing operation that cuts a large roll of material into narrower rolls. There are two types of slitting: log slitting and rewind slitting. In log slitting the roll of material is treated as a whole and one or more slices are taken from it without an unrolling/re-reeling process. In rewind slitting the web is unwound and run through the machine, passing through knives or lasers, before being rewound on one or more shafts to form narrower rolls. The multiple narrower strips of material may be known as mults or pancakes if their diameter is much more than their width. For rewind slitting the machine used is called a slitter rewinder, a slitter or a slitting machine – these names are used interchangeably for the same machines. For particularly narrow and thin products, the pancakes become unstable, and then the rewind may be onto a bobbin-wound reel: the rewind bobbins are much wider than the slit width and the web oscillates across the reel as it is rewound. Apart from the stability benefit it is also then possible to put very long lengths,, onto one bobbin.

<span class="mw-page-title-main">Photochemical machining</span> Process that uses chemicals to machine sheet metal

Photochemical machining (PCM), also known as photochemical milling or photo etching, is a chemical milling process used to fabricate sheet metal components using a photoresist and etchants to corrosively machine away selected areas. This process emerged in the 1960s as an offshoot of the printed circuit board industry. Photo etching can produce highly complex parts with very fine detail accurately and economically.

Shearing, also known as die cutting, is a process that cuts stock without the formation of chips or the use of burning or melting. Strictly speaking, if the cutting blades are straight the process is called shearing; if the cutting blades are curved then they are shearing-type operations. The most commonly sheared materials are in the form of sheet metal or plates. However, rods can also be sheared. Shearing-type operations include blanking, piercing, roll slitting, and trimming. It is used for metal, fabric, paper and plastics.

There are many types of shears used to shear or cut sheet metal.

<span class="mw-page-title-main">Vinyl cutter</span>

A vinyl cutter is an entry level machine for making signs. Computer designed vector files with patterns and letters are directly cut on the roll of vinyl which is mounted and fed into the vinyl cutter through USB or serial cable. Vinyl cutters are mainly used to make signs, banners and advertisements. Advertisements seen on automobiles and vans are often made with vinyl cut letters. While these machines were designed for cutting vinyl, they can also cut through computer and specialty papers, as well as thicker items like thin sheets of magnet.

In metallurgy, peening is the process of working a metal's surface to improve its material properties, usually by mechanical means, such as hammer blows, by blasting with shot, focusing light, or in recent years, with water column impacts and cavitation jets. With the notable exception of laser peening, peening is normally a cold work process tending to expand the surface of the cold metal, thus inducing compressive stresses or relieving tensile stresses already present. It can also encourage strain hardening of the surface metal.

Decapping (decapsulation) or delidding of an integrated circuit is the process of removing the protective cover or integrated heat spreader (IHS) of an integrated circuit so that the contained die is revealed for visual inspection of the micro circuitry imprinted on the die. This process is typically done in order to debug a manufacturing problem with the chip, or possibly to copy information from the device, to check for counterfeit chips or to reverse engineer it. Companies such as TechInsights and ChipRebel decap, take die shots of, and reverse engineer chips for customers. Modern integrated circuits can be encapsulated in plastic, ceramic, or epoxy packages.

References

  1. "Basic Studies Of Stress And Strain" (PDF). www.freestudy.co.uk. Archived (PDF) from the original on 13 December 2016. Retrieved 5 February 2016.
  2. "FAQ: What are the problems with laser cutting of aluminium and how do I overcome them?". www.twi-global.com. Archived from the original on 2016-01-21. Retrieved 2016-02-05.
  3. "Laser Etching & Cutting Services". HPL Stampings. Archived from the original on 2016-03-25. Retrieved 2016-02-05.