Iron

One element of the medical approach is a specific chelating agent called deferoxamine, used to bind and expel excess iron from the body in case of iron toxicity. Kayaks designed for Slalom canoeing have a hull for manouverability and since the early 1970's, low profile decks. The medical management of iron toxicity is complex. Besides being portable, inflatable kayaks generally are stable and easy to master, but they take more effort to paddle and are slower than traditional kayaks. Blood donors are at special risk of low iron levels and are often recommended to supplement their iron intake. They are made of hypalon (a kind of neoprene), pvc, or polyurethane coated cloth. For this reason, people should not take iron supplements unless they suffer from iron deficiency and have consulted a doctor. The pressure sounds low, almost always below 3 psi.

Iron overload disorders require a genetic inability to regulate iron uptake; however, many people have a genetic susceptibility to iron overload without realizing it and without knowing a family history of the problem. They can be inflated with foot pumps, a variety of hand pumps, or electric pumps. If iron intake is excessive iron overload disorders can sometimes result, such as hemochromatosis. Inflatable kayaks usually can be transported by hand using a carry bag. For children under fourteen years old the UL is 40 mg/day. Another special type of kayak is the inflatable kayak. The DRI lists the Tolerable Upper Intake Level (UL) for adults as 45 mg/day. Surf Skis were originally created for surf and are still used in surf races in countries such as New Zealand, Australia, South Africa.

Humans experience iron toxicity above 20 milligrams of iron for every kilogram of weight, and 60 milligrams per kilogram is a lethal dose.[3] Over-consumption of iron, often the result of children eating large quantitities of ferrous sulfate tablets intended for adult consumption, is the most common toxicological cause of death in children under six. A highly specialized variant of flatwater racing kayak called a Surf Ski has an open cockpit and can be twenty-one feet long but only eighteen inches wide, requiring expert balance and paddling skill. This can cause serious problems, including the potential of death from overdose, and long-term organ damage in survivors. Flatwater racing kayaks are closely related to flatwater racing canoes, and are usually paddled out of a common club or team, although it is rare for paddlers to compete in both canoes and kayaks. Once there, it causes damage to cells in the heart, liver and elsewhere. In spite of this, these boats still require fairly large areas to turn. However, too much ingested iron can damage the cells of the gastrointestinal tract directly, and may enter the bloodstream by damaging the cells that would otherwise regulate its entry. The rudder is controlled by the feet of the paddler (the foremost paddler in multiperson designs).

Iron uptake is tightly regulated by the human body, which has no physiologic means of excreting iron and regulates iron solely by regulating uptake. Due to their long length (a one person sprint kayak will be on the order of 17 feet long), sprint boats come equipped with a rudder to help with turning. In excess, uncontrollable quantities of free radicals are produced. These boats are raced at the Olympic level by both men and women, over courses of 200m, 500m and 1000m. Iron becomes toxic when it exceeds the amount of transferrin needed to bind free iron. The most common types of flatwater racing kayaks (sometimes termed 'sprint boats') are K-1, K-2 and K-4. Excessive iron is toxic to humans, because excess ferrous iron reacts with peroxides in the body, producing free radicals. The beam of a flatwater boat is typically barely wider than the hips of the person who paddles it, allowing for a very long and narrow shape to reduce drag.

Also note the section below on precautions. They require a good level of expertise to paddle well, but are extremely fast in the hands of proficient users. The RDA for iron varies considerably based on the age, gender, and source of dietary iron (heme-based iron has higher bioavailability)[2]. They are thin, extremely unstable, and expensive, with a competitive boat running in the $4000 range. Iron provided by dietary supplements is often found as Iron (II) fumarate. Flatwater racing kayaks are generally made out of lightweight materials, and as such, are somewhat weak; they are not intended for anything other than flat water on a relatively calm day. Good sources of dietary iron include meat, fish, poultry, lentils, beans, leaf vegetables, tofu, chickpeas, black-eyed pea, strawberries and farina. Most canoe/kayak clubs will offer indroductory instruction programs in recreational boats as a way to enter into the sport.[1].

A lengthier article on the system of human iron regulation can be found in the article on human iron metabolism. Using less expensive materials like polyethylene and including fewer options keep these boats inexpensive (USA$300–$800). [1]. Compared to other kayaks recreational kayaks have a larger cockpit for easier entry and exit and a wider beam (27–30 inches) for more stability on the water; they are generally less than twelve feet in length and have limited cargo capacity. There it gets by an as yet unknown mechanism incorporated into target proteins. Recreational kayaks are designed for the casual paddler interested in fishing, photography, or a peaceful paddle on a lake or flatwater stream; they presently make up the largest segment of kayak sales. The iron absorbed from the duodenum binds to transferrin, and is carried by blood to different cells. Elite waveski surfers are able to more closely imitate surfboard manouveres.

Iron distribution is heavily regulated in mammals, both as a defense against bacterial infection as well as the potential biological toxicity of iron. Although the waveski utilises similar dynamics, in terms of paddling technique and surfing performance on the waves, construction can be very similar to surfboard designs. When the body is fighting a bacterial infection, the body sequesters iron inside of cells (mostly stored in the storage molecule ferritin) so that it cannot be used by bacteria. A variation on the closed cockpit surf kayak is an open cockpit design called a Waveski. A class of non-heme iron proteins is responsible for a wide range of functions within several life forms, such as enzymes methane monooxygenase (oxidizes methane to methanol), ribonucleotide reductase (reduces ribose to deoxyribose; DNA biosynthesis), hemerythrins (oxygen transport and fixation in marine invertebrates) and purple acid phosphatase (hydrolysis of phosphate esters). While typically seven or eight feet in length, competition surf kayaks can be nearly twelve feet long to increase both planing speed while on a wave and to provide faster paddling speed for catching waves. Inorganic iron involved in redox reactions is also found in the iron-sulfur clusters of many enzymes, such as nitrogenase (involved in the synthesis of ammonia from nitrogen and hydrogen) and hydrogenase. Surf Kayaks are similar in design to whitewater kayaks, except they have a planing hull (flat side to side) to carve into a wave face, like a surfboard.

Many animals incorporate iron into the heme complex, an essential component of cytochromes, which are proteins involved in redox reactions (including but not limited to cellular respiration), and of oxygen carrying proteins hemoglobin and myoglobin. Ultra-low-volume kayaks that are designed to be paddled both on and below the surface of the water are used in Squirt Boating. Iron binds avidly to virtually all biomolecules so it will adhere nonspecifically to cell membranes, nucleic acids, proteins etc. In "freestyle" competition ("kayak rodeo"), whitewater kayakers use features of rapids to do tricks, typically while remaining in one place on the river. To say that iron is free doesn't mean that it is free floating in the bodily fluids. Their speed comes from their ability to ride the crest of flowing river. It is mostly stably incorporated in the inside of metalloproteins, because in exposed or in free form it causes production of free radicals that are generally toxic to cells. Whitewater boats, however, do not need inherent speed.

Iron is essential to all organisms, except for a few bacteria. Whitewater kayaks are among the most maneuverable types made, however they are much slower than many other styles of boat. For this reason, ⁵⁷Fe has application as a spin isotope in chemistry and biochemistry. The size usually ranges from 6 to 10 feet/2 to 3 metres long; the trend was toward the shorter boats, but this is now reversing slightly to longer boats of around 7 to 8 feet that can become airborne more easily. Of the stable isotopes, only ⁵⁷Fe has a nuclear spin (−1/2). They are shorter than other types of kayaks. The abundance of ⁶⁰Ni present in extraterrestrial material may also provide further insight into the origin of the solar system and its early history. Whitewater kayaks are generally made out of high impact plastic, usually polyethylene.

Possibly the energy released by the decay of ⁶⁰Fe contributed, together with the energy released by decay of the radionuclide ²⁶Al, to the remelting and differentiation of asteroids after their formation 4.6 billion years ago. Of all modern kayaks, they are closest relatives to the skin-and-frame boats of the past. In phases of the meteorites Semarkona and Chervony Kut a correlation between the concentration of ⁶⁰Ni, the daughter product of ⁶⁰Fe, and the abundance of the stable iron isotopes could be found which is evidence for the existence of ⁶⁰Fe at time formation of solar system. Folding kayaks exhibit many of the same paddling characteristics as the original skin-and-frame vessels of the circumpolar north. This is not true, as both ⁶²Ni and ⁵⁸Fe are more stable. Folders are known for their durability, stability, and longevity: The Klepper Aerius I, a single-seater, has been used successfully for white-water kayaking, due to its durability and excellent manouvrability, while many Kleppers have been in frequent use for more than 20 years. A common misconception is that this isotope represents the most stable nucleus possible, and that it thus would be impossible to perform fission or fusion on ⁵⁶Fe and still liberate energy. Many types have integral air sponsons inside the hull, making the kayaks virtually unsinkable.

The isotope ⁵⁶Fe is of particular interest to nuclear scientists. A folder is a modern kayak that uses a collapsible frame, of wood, aluminum or plastic, or a combination thereof, and a skin, of some sort of water-resistant and tough fabric. Much of the past work on measuring the isotopic composition of Fe has centered on determining ⁶⁰Fe variations due to processes accompanying nucleosynthesis (i.e., meteorite studies) and ore formation. A special type of skin-on-frame kayak is the folding kayak, the direct descendant of the original Inuit kayak. ⁶⁰Fe is an extinct radionuclide of long half-life (1.5 million years). Lending maneuverability traits more adapted to the local environment. Naturally occurring iron consists of four isotopes: 5.845% of radioactive ⁵⁴Fe (half-life: >3.1E22 years), 91.754% of stable ⁵⁶Fe, 2.119% of stable ⁵⁷Fe and 0.282% of stable ⁵⁸Fe. East Greenland kayaks appear similar to the West Greenland boat, but are often more snugly fitted to the boater and possess a steeper angle between gunwale and stem.

Iron carbide Fe₃C is known as cementite. Possessing often fewer chines they are more angular in shape, the gunwales rising to a point at the bow and stern. Note that despite the chemical formula, the iron in the common pyrite is not in the +4 oxidation state; the sulfur is in the -1 oxidation state. West Greenland kayaks are what most neo-traditional polymer boats are modeled after. Common oxidation states of iron include:. Their more rounded shape and high number of chines give them an almost Blimp-like appearance. The 1100Mt of iron ore was used to produce approximately 572Mt of pig iron. Baidarkas, from the Alaskan & Aleutian seas, and are a much older design.

While ore production occurs in 48 countries, the five largest producers were China, Brazil, Australia, Russia and India, accounting for 70% of world iron ore production. This spelling of the word kayak has evolved to be synonymous with “traditional kayak” and often encompasses three subcategories of boats separated by development local:. Approximately 1100Mt (million tons) of iron ore was produced in the world in 2000, with a gross market value of approximately 25 billion US dollars. The Dutch were some of the first Europeans to take interest in the indigenous American boat design, spelling the name for these Inuit & Aleut boats, Qajaq. The iron, once cooled, is called pig iron, while the slag can be used as a material in road construction or to improve mineral-poor soils for agriculture. They are often the lightest kayaks, and traditionally made of drift wood pegged and or lashed together and seal skin stretched over it, as those were the easiest materials to source in the arctic regions. In the bottom of the furnace, the molten slag floats on top of the more dense liquid iron, and spouts in the side of the furnace may be opened to drain off either the iron or the slag. Often an umbrella term for several types of kayaks, Skin on Frame boats are primarily considered a more traditional boat in design, materials, construction, and technique.

The slag melts in the heat of the furnace, which silicon dioxide would not have. Greenland style boats are typically narrower, and are paddled with greenland paddles, typically wooden, long and narrow. Then calcium oxide combines with silicon dioxide to form a slag. For the Inuit, without modern floatation devices or cold water protection, being thrown into the freezing waters of the Arctic Ocean was almost certain death in any event. In the heat of the furnace the limestone flux decomposes to calcium oxide (quicklime):. This meant that what is now known as a 'wet exit' (getting out of a kayak that has overturned, righting it, and getting back in) was impossible, leading to the importance of the eskimo roll maneuvre, where the kayak is righted without leaving the cockpit. Other fluxes may be used depending on the impurities that need to be removed from the ore. Because the user was sewn into the boat, it was almost like a piece of clothing, 'worn' by the boater.

Common fluxes include limestone (principally calcium carbonate) and dolomite (magnesium carbonate). Kayaks were used to hunt on the coastal and open waters of the Arctic Ocean, usually with harpoons and lances, but also with bird hooks. The flux is present to melt impurities in the ore, principally silicon dioxide sand and other silicates. This measurement style confounded early European explorers who tried to duplicate the kayak because each kayak was a little different. The carbon monoxide reduces the iron ore (in the chemical equation below, hematite) to molten iron, becoming carbon dioxide in the process:. The man would measure the frame for the kayak based on his forearm, and a typical kayak is about 19ft long. In the furnace, the coke reacts with oxygen in the air blast to produce carbon monoxide:. The skin jacket of the hunter is then sewn into the skins of the kayak, to create a waterproof seal.

In a blast furnace, iron ore, carbon in the form of coke, and a flux such as limestone are fed into the top of the furnace, while a blast of heated air is forced into the furnace at the bottom. Kayaks were originally built by the man who would use them (with substantial assistance from his wife, who would typically sew the skins). Industrially, iron is extracted from its ores, principally hematite (nominally Fe₂O₃) and magnetite (Fe₃O₄) by a carbothermic reaction (reduction with carbon) in a blast furnace at temperatures of about 2000°C. These first kayaks were constructed as a wooden frame covered by an animal skin such as seal skin. Iron is also one of the least reactive metals, and therefore, it is sometimes found pure in nature. The word "kayak" means "man's boat". Although rare, these are the major form of natural metallic iron on the earth's surface. Kayaks were originally developed by the Inuit, the indigenous peoples living in the Arctic regions of North America and Greenland.

About 5% of the meteorites similarly consist of iron-nickel alloy. . The earth's core is believed to consist largely of a metallic iron-nickel alloy. A special type of kayak using pedals allows the kayaker to propel the vessel with underwater "flippers" . Most of this iron is found in various iron oxides, such as the minerals hematite, magnetite, and taconite. Most kayaks are rigid hulled, although folding kayaks that can be transported easily, and inflatable kayaks are not uncommon. Iron is one of the most common elements on Earth, making up about 5% of the Earth's crust. There are, of course, many more elements of kayak design— see the external links for more information.

This innovation by Abraham Darby supplied the energy for the Industrial Revolution. Radical changes in design philosophy, however, have lead to whitewater kayaks with very flat hulls that allow them to sit on top of the water (planing hull) rather than in the water (displacement hull) like most other boats. In 18th century England, wood supplies ran down and coke, a fossil fuel, was used as an alternative. Until recently, whitewater kayaks had very rounded hulls. Early iron smelting (as the process is called) used charcoal as both the heat source and the reducing agent. Thus, sea kayaks, which are meant to be taken into open water and rough conditions, are generally narrower (22-25 inches) and less stable feeling than recreational kayaks, which are wider (26-30+ inches) and have a flatter hull shape. In any event, by the late fourteenth century, a market for cast iron goods began to form, as a demand developed for cast iron cannonballs. The same boats that have lower primary stability will generally be easier to right once they are tipped too far in one direction.

There are suggestions by scholars that the practice may have followed the Mongols across Russia to these sites, but there is no clear proof of this hypothesis. Secondary stability refers to the ease of righting a kayak once it has been put off balance. Some of the earliest casting of iron in Europe occurred in Sweden, in two sites, Lapphyttan and Vinarhyttan, between 1150 and 1350 AD. However, if one plans to take his or her kayak into rough water, secondary stability may be more important. Through a good portion of the Middle Ages, in Western Europe, iron was still being made by the working of sponge iron into wrought iron. Although every kayak will have some amount of side-to-side rocking, a wide kayak normally feels less likely to capsize than a narrow one, and a flat-bottomed boat will feel more stable than one with a rounded or V-shaped hull. Cast iron development lagged in Europe, as the smelters could only achieve temperatures of about 1000 K. Primary stability refers to the feeling of "tippiness" one has when seated in the kayak on flat water.

Iron, however, remained a pedestrian product, used by farmers for hundreds of years, and did not really affect the nobility of China until the Qin dynasty (ca 221 BC). After directional stabilty, the next most important design difference among kayaks is the tradeoff between primary and secondary stability. The vast majority of Chinese iron manufacture, from the Zhou dynasty onward, was of cast iron. Similarly, although a whitewater boat may only be a few feet shorter than many recreational kayaks, because the whitewater boat is heavily rockered its waterline is far shorter and its maneuverability far greater. This product is strong, can be cast into intricate shapes, but is too brittle to be worked, unless the product is decarburized to remove most of the carbon. Although kayak hulls are not so extremely curved as a hoop, it is analogous to what happens when a kayak with rocker is sitting in the water: although the overall length of the boat may be 18 feet, the length at waterline may only be 16 feet. If iron ores are heated with carbon to 1420–1470 K, a molten liquid is formed, an alloy of about 96.5% iron and 3.5% carbon. When set on its edge on a table, only a small portion of that hoop touches the table.

The famous iron pillar in the Qutb complex in Delhi is made of very pure iron (98%) and has not rusted or eroded till this day. For example, imagine a hoop 30 inches in diameter. Iron was used in India as early as 250 BCE. A heavily "rockered" boat curves more than a boat with little or no rocker, meaning that the effective waterline of the rockered boat is less than for a kayak with no rocker. Producing blast furnaces capable of temperatures exceeding 1300 K, the Chinese developed the manufacture of cast, or pig iron. A second design element that should be considered is rocker, or the curvature of the kayak from bow to stern. In the later years of the Zhou Dynasty (ca 550 BC), a new iron manufacturing capability began because of a highly developed kiln technology. Although length is an important feature of directional stability, length alone is a poor basis for guessing at the maneuverability of a kayak.

These items were made of wrought iron, created by the same processes used in the Middle East and Europe, and were thought to be imported by non-Chinese people. The design of recreational kayaks is an attempt to compromise between tracking and maneuverability, while keeping costs reasonable; their length generally ranges from nine to fourteen feet. In China the first irons used were also meteoric iron, with archeological evidence for items made of wrought iron appearing in the northwest, near Xinjiang, in the 8th century BC. These kayaks rarely exceed eight feet in length, and some specialized boats such as playboats may be only six feet long. The resulting product, which had a surface of steel, was harder and less brittle than the bronze it began to replace. Whitewater kayaks, which generally depend upon river current for their forward motion, are built quite short, to maximize maneuverability. The people of the Middle East found that a much harder product could be created by the long term heating of a wrought iron object in a bed of charcoal, which was then quenched in water or oil. Flat water racing kayaks, which are built for maximum speed and efficiency, may be over 20 feet in length.

Wrought iron was very low in carbon content and was not easily hardened by quenching. Kayaks that are built to cover longer distances such as touring and sea kayaks are themselves longer, generally between 15 and 18 feet. Iron was recovered as sponge iron, a mix of iron and slag with some carbon and/or carbide, which was then repeatedly hammered and folded over to free the mass of slag and oxidise out carbon content, so creating the product wrought iron. Longer boats also have a higher maximum non-planing hull speed, but the effect is largely offset by increased friction, and only becomes a significant factor at racing speeds. Concurrent with the transition from bronze to iron was the discovery of carburization, which was the process of adding carbon to the irons of the time. A longer hull creates a smoother transition from the narrow bow to the widest part of the boat and so "cuts" through the water with less resistance much like a sharp knife cuts more easily than a dull one. A common alchemical symbol for iron, the metal of weapons, was that of Mars, the god of war. As a general rule, a longer boat is faster while a shorter boat may be turned more quickly.

This period of transition, which occurred at different times in different parts of the world, is the ushering in of an age of civilization called the Iron Age. The first trade-off important to all kayaks is between directional stability ("tracking") and maneuverability. The critical factor in this transition does not appear to be the sudden onset of a superior ironworking technology, but instead the disruption of the supply of tin. The design of different types of kayak is largely a matter of two types of trade-offs. In the period from the 12th to 10th century BC, there was a rapid transition in the Middle East from bronze to iron tools and weapons. Some sit-on-top boats are also called kayaks, as the paddler propels the boat with a double-ended paddle. By 1600 BC to 1200 BC, iron was used increasingly in the Middle East, but did not supplant the dominant use of bronze. They come in one, two, and occasionally three person models.

Some resources (see the reference What Caused the Iron Age? below) suggest that iron was being created then as a by-product of copper refining, as sponge iron, and was not reproducible by the metallurgy of the time. Modern kayaks are made of plastic, fiberglass, kevlar, carbon fiber, canvas, other fabrics, or wood. In the Iliad, weaponry is mostly bronze, but iron ingots are used for trade. These types may also be subdivided. However, their use appears to be ceremonial, and iron was an expensive metal, more expensive than gold. In modern times kayaks have been further developed into several types including: whitewater, playboats, surfing, sea kayaks, flat-water racing, downriver racing, slalom, canoe polo and recreational. By 3500 BC to 2000 BC, increasing numbers of smelted iron objects (distinguishable from meteoric iron by the lack of nickel in the product) appear in Mesopotamia, Anatolia, and Egypt. This manoeuvre is known as an Eskimo Roll.

Because meteorites fall from the sky some linguists have conjectured that the English word iron (OE īsern), which has cognates in many northern and western European languages, derives from the Etruscan aisar which means "the gods". This stops water splashing over the boat from entering it, and makes it possible that, should the kayak (capsize), the kayak will not fill with water, and the paddler, with skill, can right the kayak again without taking on water. The first signs of use of iron come from the Sumerians and the Egyptians, where around 4000 BC, a few items, such as the tips of spears, daggers and ornaments, were being fashioned from iron recovered from meteorites. The paddler sits in a hole in the cockpit which may be sealed off with a spray skirt (or spraydeck). Steel is the best known alloy of iron, and some of the forms that iron takes include:. The top of the kayak is covered with a deck. Its combination of low cost and high strength make it indispensable, especially in applications like automobiles, the hulls of large ships, and structural components for buildings. The user or paddler sits down in the kayak with feet facing forward.

Iron is the most used of all the metals, comprising 95 percent of all the metal tonnage produced worldwide. A kayak is a type of small human-powered boat and is a covered variant of a canoe, it is often called a canoe in Great Britain and Ireland, typically used with a double-bladed paddle instead of a canoe's single bladed paddle. Some cosmological models with an open universe predict that there will be a phase where as a result of slow fusion and fission reactions, everything will become iron. This leads to a supernova. When a very large star contracts at the end of its life, internal pressure and temperature rise, allowing the star to produce progressively heavier elements, despite these being less stable than the elements around mass number 60 (the "iron group").

Although a further tiny energy gain could be extracted by synthesizing ⁶²Ni, conditions in stars are not right for this process to be favoured. This is formed by nuclear fusion in the stars. The universally most abundant of the highly stable nucleides is, however, ⁵⁶Fe. Nuclei of iron have some of the highest binding energies per nucleon, superseded only by the nickel isotope ⁶²Ni.

Iron is used in the production of steel, which is not an element but an alloy, a solution of different metals (and some non-metals, particularly carbon). In order to obtain elemental iron, the impurities must be removed by chemical reduction. Iron is a metal extracted from iron ore, and is hardly ever found in the free (elemental) state. Iron is also the most abundant (by mass, 34.6%) element making up the Earth; the concentration of iron in the various layers of the Earth ranges from high at the inner core to about 5% in the outer crust; it is possible the Earth's inner core consists of a single iron crystal although it is more likely to be a mixture of iron and nickel; the large amount of iron in the Earth is thought to contribute to its magnetic field.

Iron is the most abundant metal on Earth, and is believed to be the tenth most abundant element in the universe. . It is therefore the most abundant heavy metal in the universe. Iron is notable for being the final element produced by stellar nucleosynthesis, and thus the heaviest element which does not require a supernova or similarly cataclysmic event for its formation.

Iron is a group 8 and period 4 metal. Iron is a chemical element with the symbol Fe (L.: Ferrum) and atomic number 26. Los Alamos National Laboratory — Iron. the Iron(VI) state, Fe⁶⁺ is also known, if rare, in potassium ferrate.

peroxidases). the Iron(IV) state, Fe⁴⁺, previously ferryl, stabilized in some enzymes (e.g. the Iron(III) state, Fe³⁺, previously ferric, is also very common, for example in rust. the Iron(II) state, Fe²⁺, previously ferrous is very common.

the Iron(I) state, [Fe(H₂O)₅NO]²⁺. the Iron(0) state, Fe(CO)₅, Fe(PF₃)₅. Fe(CO)₄^2-,Fe(CO)₂(NO)₂. the Iron(-II) state, Fe^2- (e.g.

They are often mixed with other compounds, and retain their magnetic properties in solution. Iron(III) oxides are used in the production of magnetic storage in computers. Recent developments in ferrous metallurgy have produced a growing range of microalloyed steels, also termed 'HSLA' or high-strength, low alloy steels, containing tiny additions to produce high strengths and often spectacular toughness at minimal cost. They are used for structural purposes, as their alloy content raises their cost and necessitates justification of their use.

Alloy steels contain varying amounts of carbon as well as other metals, such as chromium, vanadium, molybdenum, nickel, tungsten, etc. Wrought iron is characterised, especially in old samples, by the presence of fine 'stringers' or filaments of slag entrapped in the metal. If honed to an edge, it loses it quickly. It has a very small amount of carbon, a few tenths of a percent.

It is a tough, malleable product, not as fusible as pig iron. Wrought iron contains less than 0.2% carbon. Carbon steel contains between 0.4% and 1.5% carbon, with small amounts of manganese, sulfur, phosphorus, and silicon. A newer variant of grey iron, referred to as 'ductile iron' is specially treated with trace amounts of magnesium to alter the shape of graphite to sheroids, or nodules, vastly increasing the toughness and strength of the material.

In 'grey' cast iron, the carbon exists free as fine flakes of graphite , and also, renders the material brittle due to the stress-raising nature of the sharp edged flakes of graphite. The broken surface of a white cast iron is full of fine facets of the broken carbide, a very pale, silvery, shiny material, hence the appellation. This hard, brittle compound dominates the mechanical properties of white cast irons, rendering them hard, but unresistant to shock. 'White' cast irons contain their carbon in the form of cementite, or iron carbide.

Its mechanical properties vary greatly, dependant upon the form carbon takes in the alloy. It has a melting point in the range of 1420–1470 K, which is lower than either of its two main components, and makes it the first product to be melted when carbon and iron are heated together. Contaminants present in pig iron that negatively affect the material properties, such as sulfur and phosphorus, have been reduced to an acceptable level. Cast iron contains 2% – 4.0% carbon , 1% – 6% silicon , and small amounts of manganese.

Its only significance is that of an intermediate step on the way from iron ore to cast iron and steel. Pig iron has 4% – 5% carbon and contains varying amounts of contaminants such as sulfur, silicon and phosphorus.