A wrought iron railing in Troy, New York.

Wrought iron is commercially pure iron, having a very small carbon content (carbon content does not exceed 0.15 percent), but usually contains some slag. It is tough, malleable, ductile and can be easily welded. However, it is too soft to make blades and swords, or at least for their cutting edges, which need to be made of steel with a higher carbon content. Image File history File linksMetadata Download high resolution version (2272x1704, 819 KB) Summary A railing in Troy, NY. Licensing File links The following pages link to this file: Wrought iron Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... Image File history File linksMetadata Download high resolution version (2272x1704, 819 KB) Summary A railing in Troy, NY. Licensing File links The following pages link to this file: Wrought iron Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... A system designed to keep people or vehicles from (in most cases unintentionally) straying into dangerous or off-limits areas. ... Looking west down Broadway at downtown Troy. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... For the Transformers character, see Slag (Transformer). ... Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. ... The old steel cable of a colliery winding tower Steel is a metal alloy whose major component is iron, with carbon content between 0. ...

Common usage is for 'wrought iron' to mean iron of this composition. However, strictly, it should be confined to iron that has been wrought (i.e. worked) into a finished product. The unwrought commodity is according to its form 'bar iron', 'rod iron', etc. Wrought iron has been used for thousands of years, and represents the "iron" that is referred to throughout history.

Ornamental ironwork is often referred to as "wrought iron," even though today it is more likely to be made from mild steel. Plain-carbon steel is a metal alloy, a combination of two elements, iron and carbon, where other elements are present in quantities too small to affect the properties. ...

Wrought iron is rarely completely pure. It is a fibrous material with many strands of slag mixed into the metal. These slag inclusions give it a "grain" like wood, and distinct look when etched. Also due to the slag, it has a fibrous look when broken or bent past its failure point. In mineralogy, an inclusion is any material that is trapped inside a mineral during its formation. ...

The fibers of wrought iron gives it some interesting properties, however. Hammering a piece of wrought iron cold causes the fibers to become packed tighter, which makes the iron both brittle and hard. As wrought iron lacks the carbon content necessary for tempering, it is believed that cultures that never discovered how to make steel would cold work wrought iron tools in order to harden them. Tempering is a heat treatment technique for metals and alloys. ...

Word origin

The word "wrought" is the past tense of the verb to wreak (i.e. to make or to work) and is related to the noun wright (builder or worker) as in compound words like cartwright (one who builds carriages), boatwright (one who works on the building of boats), and millwright (one who keeps the machinery of a mill working). As irregular past-tense forms in English have historically been phased out over long periods of time, wrought became wreaked in some idiolects, just as sought became seeked and raught became reached. To English speakers with little understanding of the language as it was used prior to their own lifetimes, past-tense verbs like raught, wrought, and sought may sound archaic, and to such individuals it might help to say that wrought iron "means" worked iron, though in reality it simply means wrought iron. An idiolect is a variety of a language unique to an individual. ...

Bloomery process

Wrought iron was originally produced by a variety of smelters, described today as bloomeries. Bloomeries probably existed in a number of forms at different places and times. The bloomery would be charged with charcoal and iron ore (an oxide or carbonate) and lit. Air was blown in through a tuyere to heat the bloomery to a temperature somewhat below the melting point of iron. In the course of the smelt, slag would melt and run out, and carbon monoxide from the charcoal would reduce the ore to iron, which formed a spongy mass. The iron remained in the solid state. If the bloomery was allowed to become hot enough to melt the iron, carbon would dissolve into it and form pig iron, but that was not the intention. A bloomery is a type of furnace once widely used for smelting iron from its oxides. ... Charcoal is the blackish residue consisting of impure carbon obtained by removing water and other volatile constituents from animal and vegetation substances. ... An oxide is a chemical compound of oxygen with other chemical elements. ... In inorganic chemistry, a carbonate is a salt of carbonic acid. ... Carbon monoxide, chemical formula CO, is a colorless, odorless, tasteless, and highly toxic gas. ...

After smelting was complete, the bloom was removed, and the process can be started again. It is thus a batch-based process, rather than a continuous one. The spongy mass contains iron and also silicates (slag) from the ore; this is iron bloom from which the technique gets its name. The bloom then has to be forged mechanically to consolidate it and shape it into a bar, expelling slag in the process. Iron bloom (in German Eisenblüte) is a mixture of fine iron particles, unreacted iron oxide (ore), slag and charcoal residue. ...

During the Middle Ages, water-power was applied to the process, probably initially only for powering bellows, and only later to hammers for forging the blooms. However, while it is certain that water-power was used, the details of this remain uncertain. This was the culmination of the direct process of ironmaking. It survived in the Spain and southern France as Catalan Forges to the mid 19th century, in Austria as the stuckofen to 1775; near Garstang in England until about 1770; and was still in use with hot blast in New York State in the 1880s. The Middle Ages formed the middle period in a traditional schematic division of European history into three ages: the classical civilization of Antiquity, the Middle Ages, and modern times, beginning with the Renaissance. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... Garstang is a small town in the North of England situated on the A6 between Lancaster and Preston, a short distance from Knott End-on-Sea and Myerscough College. ... 1770 was a common year starting on Monday (see link for calendar). ... Hot Blast refers to the air blown into a blast furnace or other metallurgical process being preheated. ... State nickname: Empire State Other U.S. States Capital Albany Largest city New York Governor George Pataki Official languages None Area 141,205 km² (27th)  - Land 122,409 km²  - Water 18,795 km² (13. ... // Events and Trends Technology Development and commercial production of electric lighting Development and commercial production of gasoline-powered automobile by Karl Benz, Gottlieb Daimler and Maybach First commercial production and sales of phonographs and phonograph recordings. ...

Indirect processes

The direct process was however generally replaced long before that, with an indirect smelting process, involving a blast furnace and then one of a succession of a further processes, including the finery forge, and later the puddling furnace. Chemical reduction, or smelting, is a form of extractive metallurgy. ... It has been suggested that Old Furnace, Ironbridge be merged into this article or section. ... Iron tapped from the blast furnace is pig iron, and contains significant amounts of carbon and silicon. ... Schematic drawing of a puddling furnace The puddling furnace is a metalmaking technology to create wrought iron from the pig iron produced in a blast furnace. ...

Examples of the blast furnace have been discovered from the Middle Ages at Lapphyttan, Sweden and in Germany. This was combined with a further process making osmond iron, balls of wrought iron. The Middle Ages formed the middle period in a traditional schematic division of European history into three ages: the classical civilization of Antiquity, the Middle Ages, and modern times, beginning with the Renaissance. ... Lapphyttan in Sweden may be regarded as the type site for the Medieval Blast Furnace. ... Osmond iron (also spelt osmund and also called osborn) was wrought iron made by a particular process. ...

In the 15th century, the blast furnace spread into what is now Belgium and was improved. From there, it spread via the pays de Bray on the boundary of Normandy and then to the Weald in England. The product of a blast furnace, pig iron, had a high carbon content and was brittle. In order to use it in ironmongery, this had to be converted to wrought iron. This was the function of the finery forge and succesor processes. These remelted the pig iron and (in effect) burnt out the carbon, producing a bloom, which was then forged into a bar. If rod iron was required a slitting mill was used. (14th century - 15th century - 16th century - other centuries) As a means of recording the passage of time, the 15th century was that century which lasted from 1401 to 1500. ... Mont Saint Michel, one of the famous symbols of Normandy. ... A weald once meant a dense forest, especially the famous great wood once stretching far beyond the ancient counties of Sussex and Kent, England, where this country of smaller woods is still called the Weald. ... Motto: (French for God and my right) Anthem: Multiple unofficial anthems Capital London Largest city London Official language(s) English Government Constitutional monarchy  - Queen Queen Elizabeth II  - Prime Minister Tony Blair MP Unification    - by Athelstan AD927  Area    - Total 130,395 km² (1st in UK)   50,346 sq mi   - Water (%) Population... Pig iron is raw iron, the immediate product of smelting iron ore with coke and limestone in a blast furnace. ... Iron tapped from the blast furnace is pig iron, and contains significant amounts of carbon and silicon. ... The Slitting Mill was a water-powered mill for slitting bars of iron into rods. ...

The introduction of coke for use in the blast furnace by Abraham Darby in 1709 (or perhaps others a littler earlier) changed ironmaking and eventually replaced charcoal. Not only was the fuel much cheaper, but it is also less friable, allowing the furnaces to be much larger. However, charcoal continued to be the fuel for the finery. Coke is a solid carbonaceous residue derived from low-ash, low-sulfur bituminous coal. ... It has been suggested that Old Furnace, Ironbridge be merged into this article or section. ... Abraham Darby (c. ... // Events January 12 - Two-month freezing period begins in France - The coast of the Atlantic and Seine River freeze, crops fail and at least 24. ...

The Industrial Revolution

A number of processes were devised in the second half of the 18th century for making wrought iron without charcoal. The most successful of these was the puddling furnace invented by Henry Cort in 1784. The fully deveoped process involved a series of processes. First the iron was melted in a 'refinery' or 'running out fire'. The iron was run out into a trough whose dam was lowered enough to run off the slag, thus reducing the silicon content. This produced a brittle white metal ('finers metal'). The finers metal was charged to the puddling furnace, where it was melted and stirred. The resultant puddled ball was 'shingled' with a hammer and then rolled in a rolling mill to produce 'muck bar'. This would be broken up and faggotted. Wrought iron which had been faggoted twice was referred to as "Best"; if faggoted again it would become "Best Best", then "Treble best", etc. (17th century - 18th century - 19th century - more centuries) As a means of recording the passage of time, the 18th century refers to the century that lasted from 1701 through 1800. ... Charcoal is the blackish residue consisting of impure carbon obtained by removing water and other volatile constituents from animal and vegetation substances. ... Schematic drawing of a puddling furnace The puddling furnace is a metalmaking technology to create wrought iron from the pig iron produced in a blast furnace. ... During the Industrial Revolution in England, Henry Cort began refining iron from pig iron to wrought iron using innovative production systems. ... 1784 was a leap year starting on Thursday (see link for calendar). ... Shingling was a stage in the production of bar iron or steel, in the finery and puddling processes. ... Faggoting or faggoting and folding is a metalworking technique used in the smelting and forging of wrought iron, damascus steel, and other steel. ...

Faggoting resulted in impurities within the metal ending up as long thin inclusions, creating a grain within the metal. "Best" bars would have a tensile strength along the grain of about 23 tons per square inch (317 MPa). "Treble best" could reach 28 tons per square inch (386 MPa). The strengths across the grain would be about 15% lower. This grain makes wrought iron especially tricky to smith, as it behaves much like wood grain--prone to spontaneous splitting along the grain. In old, very rusted pieces of wrought iron, the grain is revealed, making the iron bear a striking resemblance to reddish-brown wood. Faggoting or faggoting and folding is a metalworking technique used in the smelting and forging of wrought iron, damascus steel, and other steel. ... It has been suggested that this article or section be merged into Strength of materials. ...

Modern Production of Wrought Iron

Wrought iron is almost pure iron and it hardly contains carbon more than 0.15 per cent or so. But the process of its manufacture is laborious and tedious. Following are the four distinct operations involved in its manufacture:

(1) Refining (2) Puddling (3) Shingling (4) Rolling

Refining

Pig iron is melted and a strong current of air is directed over it. It is being well agitated or stirred when the current of air is passing over. It is thus thoroughly oxidized. It is then cast into moulds. It is cooled suddenly so as to make it brittle. This is known as ‘’refined pig iron’’.

Puddling

Main article: puddling furnace

Conversion of pig iron into wrought iron by stirring in a molten state is known as puddling. It is carried out in a reverberatory furnace. In this type of furnace, the metal does not come into contact with the fuel and flame from the fire is reverted or sent back on the metal in the hearth. Schematic drawing of a puddling furnace The puddling furnace is a metalmaking technology to create wrought iron from the pig iron produced in a blast furnace. ... Pig iron is raw iron, the immediate product of smelting iron ore with coke and limestone in a blast furnace. ... Schematic drawing of a puddling furnace The puddling furnace is a metalmaking technology to create wrought iron from the pig iron produced in a blast furnace. ...

A reverberatory furnace is of rectangular shape. It is built with refractory materials such as firebricks. The combustion chamber and the chimney are situated on opposite ends. Grating is provided in combustion chamber to collect ash in ash pit. Next to combustion chamber is the hearth portion with shallow depth. Hearth lining consists of molten slag or rich iron ore. It is supported on steel plates, which in turn are supported on dwarf brick walls. Water jackets are provided for circulation of water to cool the furnace. Various doors or openings for fuel feeding, working and slag removal are provided. The roof is given a peculiar shape so that flames of gas produced are concentrated on hearth. A reverbatory furnace is a metallurgical or process furnace which characteristically isolates the material being processed from contact with the fuel, but not from contact with the combustion gases. ...

The refined pig iron is broken into lumps and it is melted in hearth of reverberatory furnace. The hearth lining acts as an oxidizing agent and in addition, oxidizing substances such as haematite ore, oxide of iron, etc. are added to the refined pig iron. It is subjected to intense heat and a strong current of air. It is kept well stirred by long bars through working doors.

During the process of puddling, most of the carbon content and other impurities of pig iron are oxidized. Slag formed is removed through slag removal door. The purified iron becomes thick and it assumes the form of white spongy iron balls. These known as puddle balls and weight of each ball is about 50 kg to 70 kg.

Shingling

Main article: Shingling (metallurgy)

By this operation, the slag contained is removed. It may be achieved by forging the balls under a power hammer or by passing the balls through a squeezing machine. In the case of the power hammer, the balls are placed on an anvil and a falling hammer forges them. A squeezing machine consists of two cylinders, which are placed one inside the other. The smaller cylinder has corrugations on its outer surface and the larger cylinder has corrugations on its inner surface. The balls are placed in between the cylinders and then the inner cylinder is rotated. Shingling was a stage in the production of bar iron or steel, in the finery and puddling processes. ...

Shingling also helps in binding or welding the particles of puddle balls. The material obtained at the end of shingling is known as bloom and it is still in red-hot condition.

Rolling

Main article: Rolling mill

The bloom is passed through grooved rollers and flat bars of sizes such as about 4 m × 10 cm × 25 mm are obtained. These bars of wrought iron of poor quality are called muck bars. To improve the quality of wrought iron, these bars are tied together by wires, a process known as faggoting and they are heated and rolled again. This process may be repeated several times to get wrought iron of desired quality. A rolling mill is a machine or factory for shaping metal by passing it between rollers. ... Faggoting or faggoting and folding is a metalworking technique used in the smelting and forging of wrought iron, damascus steel, and other steel. ...

Aston's Process

This process of manufacturing wrought iron was developed by James Aston of the United States in 1925. This process is wholly mechanical and by this process, wrought iron can be manufactured quickly and economically. It is carried out as follows: 1925 (MCMXXV) was a common year starting on Thursday (link will take you to calendar). ...

1. Molten steel from bessemer converter is poured into cooler liquid slag. Temperature of molten steel is about 1500°C and that of liquid slag is about 1200°C.
2. Molten steel contains large amounts of dissolved gases. These gases are liberated when it strikes the slag.
3. Molten steel freezes and it results in a spongy mass having a temperature of about 1370°C.
4. This spongy mass is then given the treatmant of shingling and rolling as described above.

Shingling was a stage in the production of bar iron or steel, in the finery and puddling processes. ... A wrought iron railing in Troy, New York. ...

Properties

Following are the properties of wrought iron:

1. It becomes soft at white heat and it can be easily forged and welded.
2. It can be used to form temporary magnets, but cannot be magnetized permanently.
3. It fuses with difficulty. It cannot, therefore, be adopted for making castings.
4. It is ductile, malleable and tough.
5. It is moderately elastic.
6. It is unaffected by saline water.
7. It resists corrosion in a better way.
8. Its fresh fracture shows clear bluish colour with a high silky luster and fibrous appearance.
9. Its melting point is about 1500°C.
10. Its specific gravity is about 7.8.
11. Its ultimate compressive strength is about 2000 kg/cm².
12. Its ultimate tensile strength is about 4000kg/cm².

This article is about smithing. ... Welding is a joining process that produces coalescence of materials (typically metals or thermoplastics) by heating them to welding temperature, with or without the application of pressure or by the application of pressure alone, and with or without the use of filler material. ... Iron filings in a magnetic field generated by a bar magnet A magnet is an object that has a magnetic field. ... Casting is a process by which a fluid melt is introduced into a mold, allowed to cool in the shape of the form, and then ejected to make a fabricated part or casing. ... Ductility is the physical property of being capable of sustaining large plastic deformations without fracture (in metals, such as being drawn into a wire). ... Malleability is a physical property of matter, signifying its capability of deformation, especially by hammering or rolling. ... In materials science and metallurgy, toughness is the resistance to fracture of a material when stressed. ... Look up Elastic in Wiktionary, the free dictionary. ... Corrosion is deterioration of intrinsic properties in a material due to reactions with its environment. ... For the meaning of fiber in nutrition, see dietary fiber. ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... Compressive strength is the capacity of a material to withstand axially directed pushing forces. ... It has been suggested that this article or section be merged into Strength of materials. ...

Defects

Wrought iron is defective in quality if it is either coldshort or redshort:

Coldshort wrought iron

Coldshort or bloodshot wrought iron is very brittle when it is cold. It cracks, if bent. It may, however, be worked at high temperature. This defect occurs when phosphorus is present in excess quantity. Historically, coldshort iron was considered good enough for nails. A pile of nails Nails A twisted nail This article is about nails as used in engineering. ...

Redshort wrought iron

Redshort wrought iron possesses sufficient tenacity when cold. But it cracks when bent or finished at a red heat. It is, therefore, useless for welding or forging; indeed for almost any purpose. This defect occurs when sulphur is present in excess quantity.

Uses

Wrought iron has been replaced to a very great extent by mild steel. It is, therefore, hardly produced at all today. It was used where a tough material is required. Wrought iron, at present, is used for rivets, chains, ornamental iron work, railway couplings, water and steam pipes, raw material for manufacturing of steel, bolts and nuts, horse shoe bars, handrails, straps for timber roof trusses, boiler tubes, roofing sheets, etc. Mild steel is the most common form of steel as its price is relatively low while it provides material properties that are acceptable for many applications. ... A rivetted buffer beam on a steam locomotive A rivet is a mechanical fastener consisting of a smooth cylindrical shaft with heads on either end. ... Look up Chain in Wiktionary, the free dictionary A chain can be any of the following: a flexible connection through multiple rigid links; applications include: pulling (it cannot be used for pushing) power transmission, as in roller chains (e. ... This article is about pipes used to carry water in plumbing. ... In physical chemistry, and in engineering, steam refers to vaporized water. ... A bolt may be one of the following things: For bolts and capscrews, see Bolted joint. ... A nut is a type of hardware fastener with a threaded hole. ... Modern horseshoes are most commonly made of iron and nailed onto the hoof. ... This page is a candidate to be moved to Wiktionary. ...

See also

• Pig iron
• Ornamental metal