# History of Steel Manufacturing

> An interactive timeline of the history of steel manufacturing: 50 milestones · 168 developments, from Ancient & Medieval to Global & Green, with the connections between them.

- Interactive version: https://timelinegraph.app/examples/steel
- Published on [Timeline Graph](https://timelinegraph.app/), a free diagonal timeline maker
- Sources: [Compiled from public sources; summaries for illustration](https://en.wikipedia.org/wiki/History_of_the_steel_industry_(1850–1970))

## Eras

- **Ancient & Medieval** (1800 BCE to 1610): 12 items
- **Early Industrial** (1709 to 1828): 6 items
- **Bulk Steel Age** (1856 to 1913): 14 items
- **Modern Integrated Mills** (1919 to 1960): 8 items
- **Global & Green** (1968 to 2023): 10 items

## Kinds of connection

- Builds on
- Rivals / displaces

## Ancient & Medieval

### Anatolian & Hittite Ironworking (c. 1800–1200 BCE)

Some of the earliest deliberately smelted iron, including carburised fragments, comes from Bronze Age Anatolia. Under the Hittites iron was a prestige metal traded as diplomatic gifts before its use spread widely after the Late Bronze Age collapse.

Topics: Metallurgy, Trade, Anatolia, Bronze Age

Further reading: [Read more](https://en.wikipedia.org/wiki/History_of_ferrous_metallurgy)

- Iron fragments from Kaman-Kalehöyük in central Anatolia, dated to around 1800 BCE, include pieces with steel-like carbon content.
- A letter from Hattusili III to an Assyrian king (c. 1250 BCE) discusses requests for "good iron", showing it was a scarce, controlled commodity.
- After the Late Bronze Age collapse c. 1200 BCE, ironworking knowledge spread across the eastern Mediterranean and Near East.

Later built on by: Bloomery Smelting

### Bloomery Smelting (c. 1200 BCE onward)

The bloomery reduced iron ore with charcoal below iron’s melting point, yielding a spongy “bloom” of iron and slag. Smiths hammered the bloom into wrought iron and could harden it by carburising and quenching.

Topics: Furnaces, Metallurgy, Iron Age

Further reading: [Read more](https://en.wikipedia.org/wiki/Bloomery)

- Charcoal and ore burned in a clay shaft at about 1,200 °C produced a solid bloom rather than liquid iron.
- Repeated hammering at red heat squeezed out slag and consolidated the bloom into wrought iron.
- Smiths learned to carburise iron in charcoal and quench it in water, producing hard steel edges.
- Charcoal demand for bloomeries drove large-scale woodland clearance in many iron-making regions.

Later built on by: Japanese Tamahagane, Noric Steel, Chinese Fining & Co-fusion Steel, Indian Wootz Steel, Cementation Process, Direct Reduction (HYL & Midrex), Backyard Furnaces
Builds on: Anatolian & Hittite Ironworking
Later displaced by: European Blast Furnace, Darby’s Coke Smelting, Cort’s Puddling & Rolling

### Chinese Cast Iron (c. 5th century BCE)

By the Warring States period Chinese ironmakers ran early blast furnaces that produced liquid cast iron, centuries before Europe. Phosphorus-rich ores and efficient bellows helped lower melting points and raise furnace temperatures.

Topics: Furnaces, Casting & Rolling, China, Warring States

Further reading: [Read more](https://en.wikipedia.org/wiki/Cast_iron)

- Chinese furnaces were producing molten cast iron by the 5th century BCE, poured into moulds for tools and implements.
- Annealing cast iron produced tougher malleable iron suitable for agricultural tools.
- Emperor Wu of Han established a state monopoly on salt and iron in 117 BCE, running dozens of official ironworks.

Later built on by: Chinese Fining & Co-fusion Steel, European Blast Furnace

### Indian Wootz Steel (c. 300 BCE onward)

Wootz was a high-carbon crucible steel made in southern India and Sri Lanka by melting iron with carbonaceous material in sealed clay crucibles. Its ingots were traded across the Indian Ocean and Middle East for centuries.

Topics: Metallurgy, Trade, India, crucible

Further reading: [Read more](https://en.wikipedia.org/wiki/Wootz_steel)

- Iron and plant matter were sealed in clay crucibles and heated until the iron absorbed carbon and fully melted.
- Wootz ingots typically held around 1.5% carbon, giving bands of hard iron carbide in a softer matrix.
- Wootz cakes were exported to Persia and the Arab world, where they were forged into blades.
- Researchers J. D. Verhoeven and A. H. Pendray reproduced wootz-type patterned blades in the 1990s, linking pattern to trace vanadium.

Later built on by: Ulfberht Swords, Damascus Blades, Huntsman’s Crucible Steel
Builds on: Bloomery Smelting

### Chinese Fining & Co-fusion Steel (2nd c. BCE – 11th c. CE)

Han-dynasty smiths decarburised cast iron by stirring it in air, an early fining process known as chaogang. Later co-fusion methods blended cast and wrought iron, and Song-dynasty China reached iron output not matched in Europe until the industrial age.

Topics: Metallurgy, Fuel & Energy, China, Han, Song

Further reading: [Read more](https://en.wikipedia.org/wiki/History_of_ferrous_metallurgy)

- The chaogang (“stir-fry steel”) process decarburised molten cast iron by stirring it in an air blast, by the 1st century BCE.
- Qiwu Huaiwen in the 6th century CE described co-fusion: soaking wrought iron in molten cast iron to produce steel.
- Northern Song ironworks turned to coal as forests dwindled, and output around 1078 has been estimated at over 100,000 tonnes.

Builds on: Chinese Cast Iron, Bloomery Smelting
Later built on by: Finery Forge & Walloon Process, Darby’s Coke Smelting, Bessemer Process

### Noric Steel (c. 1st century BCE)

Noricum, in present-day Austria, exported steel prized by the Roman army. Manganese-rich ores from deposits such as the Erzberg favoured steel formation in bloomeries.

Topics: Metallurgy, Trade, Rome, Noricum

Further reading: [Read more](https://en.wikipedia.org/wiki/Noric_steel)

- Manganese-bearing ores in Noricum made it easier to obtain carburised steel directly from the bloomery.
- Noric steel became a byword for quality in Roman literature and supplied weapons for the legions.

Builds on: Bloomery Smelting
Later built on by: Mushet’s Spiegeleisen & Tool Steel

### Ulfberht Swords (c. 800–1000 CE)

About 170 Viking-age swords bear the inscription +VLFBERH+T. Some are made of unusually clean, high-carbon steel that may have been crucible steel imported from Central Asia along Volga trade routes.

Topics: Alloys, Trade, Viking, Europe

Further reading: [Read more](https://en.wikipedia.org/wiki/Ulfberht_swords)

- Around 170 swords carry the +VLFBERH+T mark, probably a Frankish workshop brand later copied.
- Metallography shows some Ulfberht blades are hypereutectoid steel with little slag, consistent with crucible steel.

Builds on: Indian Wootz Steel

### Japanese Tamahagane (c. 10th century onward)

Japanese smiths smelted iron sand with charcoal in a clay tatara furnace, producing a bloom (kera) containing tamahagane. Sorted by carbon content, it was folded and forged into the layered structure of the katana.

Topics: Furnaces, Metallurgy, Japan, tatara

Further reading: [Read more](https://en.wikipedia.org/wiki/Tamahagane)

- A tatara smelt fed iron sand and charcoal into a clay furnace for about three days, then broke it apart to recover the kera.
- Pieces of the bloom were graded by carbon content; high-carbon tamahagane formed the blade edge.
- Repeated folding homogenised carbon and removed slag, creating the katana’s hard edge and softer core.
- The Nittoho Tatara in Shimane has been run since 1977 to supply tamahagane to licensed swordsmiths.

Builds on: Bloomery Smelting

### Damascus Blades (c. 900–1750)

Damascus swords were forged in the Near East from imported wootz ingots and were famous for their toughness and flowing “watered” surface pattern. The craft declined as supplies of suitable wootz dried up.

Topics: Alloys, Trade, Middle East, swords

Further reading: [Read more](https://en.wikipedia.org/wiki/Damascus_steel)

- Careful low-temperature forging of wootz aligned carbide bands into the characteristic watered pattern.
- European encounters with Near Eastern blades during the Crusades spread their legendary reputation.
- Production faded by the 18th–19th century, likely because the specific ore sources and trade routes were lost.
- A 2006 study reported carbon nanotubes and cementite nanowires in a 17th-century Damascus sabre.

Builds on: Indian Wootz Steel
Later displaced by: Stainless Steel

### European Blast Furnace (c. 1150–1400)

Water-powered blast furnaces appeared in medieval Europe, with Lapphyttan in Sweden among the earliest known sites. They produced liquid pig iron in quantity, which then had to be refined into wrought iron.

Topics: Furnaces, Fuel & Energy, Sweden, water power

Further reading: [Read more](https://en.wikipedia.org/wiki/Blast_furnace)

- Excavations at Lapphyttan, Sweden, revealed a blast furnace operating between about 1150 and 1350.
- Water wheels drove bellows, giving a stronger blast and taller shafts than human-powered bloomeries.
- The furnace’s liquid, high-carbon pig iron was brittle and needed refining before forging.

Later built on by: Finery Forge & Walloon Process, Darby’s Coke Smelting
Displaces: Bloomery Smelting
Builds on: Chinese Cast Iron
Later displaced by: Steam-Blown Blast Furnaces

### Finery Forge & Walloon Process (15th–18th century)

Finery forges reheated pig iron in an air blast to burn out carbon and produce wrought iron. The Walloon variant, brought to Sweden by Walloon smiths, made the high-purity Öregrund iron later favoured for steelmaking.

Topics: Furnaces, Metallurgy, wrought iron

Further reading: [Read more](https://en.wikipedia.org/wiki/Finery_forge)

- Pig iron was melted in an oxidising blast in the finery, then worked in a chafery into bars of wrought iron.
- Walloon smiths in 17th-century Sweden produced Öregrund iron from low-phosphorus Dannemora ore.
- Fineries burned large quantities of charcoal, tying ironworks to forest supply.

Builds on: European Blast Furnace, Chinese Fining & Co-fusion Steel
Later built on by: Cementation Process, Bessemer Process
Later displaced by: Darby’s Coke Smelting, Cort’s Puddling & Rolling

### Cementation Process (early 17th century)

In the cementation process, wrought-iron bars were packed in charcoal and heated for about a week so carbon diffused into their surfaces. The resulting blister steel was the main raw material of Sheffield’s cutlery trade.

Topics: Furnaces, Metallurgy, blister steel

Further reading: [Read more](https://en.wikipedia.org/wiki/Cementation_process)

- Iron bars sealed with charcoal in stone chests were held near 1,000 °C for days, absorbing carbon by diffusion.
- The process was known in Nuremberg by about 1601 and was patented in England in 1614.
- Blister steel had uneven carbon, so it was piled and forge-welded into more uniform “shear steel”.

Builds on: Finery Forge & Walloon Process, Bloomery Smelting
Later built on by: Huntsman’s Crucible Steel
Later displaced by: Huntsman’s Crucible Steel

## Early Industrial

### Darby’s Coke Smelting (1709)

Abraham Darby I smelted iron with coke instead of charcoal at Coalbrookdale, Shropshire, in 1709. Freed from dwindling woodlands, British ironmaking could grow far larger.

Topics: Fuel & Energy, Furnaces, Coalbrookdale, coke

Further reading: [Read more](https://en.wikipedia.org/wiki/Abraham_Darby_I)

- In 1709 Darby used coke made from local low-sulphur coal to fuel his Coalbrookdale blast furnace.
- Darby’s thin-walled cast-iron pots and kettles were among the first products of coke-smelted iron.
- His grandson Abraham Darby III built the Iron Bridge over the Severn, opened in 1781.

Displaces: Finery Forge & Walloon Process, Bloomery Smelting
Builds on: Chinese Fining & Co-fusion Steel, European Blast Furnace
Later built on by: Huntsman’s Crucible Steel, Steam-Blown Blast Furnaces, Cort’s Puddling & Rolling, Neilson’s Hot Blast
Later displaced by: Direct Reduction (HYL & Midrex), HYBRIT Fossil-Free Steel

### Huntsman’s Crucible Steel (1740s)

Benjamin Huntsman, a Doncaster clockmaker working near Sheffield, melted blister steel in clay crucibles over a coke fire in the 1740s. The result was uniform cast steel that made Sheffield the world centre of quality steel for a century.

Topics: Metallurgy, Furnaces, Sheffield

Further reading: [Read more](https://en.wikipedia.org/wiki/Benjamin_Huntsman)

- Huntsman melted blister steel in closed crucibles heated by coke, producing homogeneous cast steel free of slag.
- He sought better steel for clock springs, as blister and shear steel were too inconsistent.
- Sheffield cutlers initially refused his hard steel, so early output went to French buyers.
- Crucible steelmaking made Sheffield the leading producer of tool and cutlery steel through the 19th century.

Later built on by: Krupp of Essen, Mushet’s Spiegeleisen & Tool Steel, Siemens–Martin Open Hearth, Stainless Steel
Builds on: Indian Wootz Steel, Cementation Process, Darby’s Coke Smelting
Displaces: Cementation Process
Later displaced by: High-Speed Steel, Héroult Electric Arc Furnace

### Steam-Blown Blast Furnaces (1776)

Ironmaster John Wilkinson used a Boulton & Watt steam engine to blow a blast furnace at Willey, Shropshire, in 1776. Steam power freed furnaces from riverside sites and allowed stronger, steadier blasts.

Topics: Fuel & Energy, Furnaces, steam, Wilkinson

Further reading: [Read more](https://en.wikipedia.org/wiki/John_Wilkinson_(industrialist))

- Wilkinson’s precise cannon-boring machine (1774) also bored the cylinders that made Watt’s engines practical.
- In 1776 a Boulton & Watt engine first powered blast-furnace bellows at Wilkinson’s Willey works.
- Steam blowing let ironworks cluster on coalfields instead of along streams.

Displaces: European Blast Furnace
Builds on: Darby’s Coke Smelting
Later built on by: Neilson’s Hot Blast

### Cort’s Puddling & Rolling (1783–1784)

Henry Cort patented grooved rolls in 1783 and the puddling process in 1784, converting coke pig iron into wrought iron with coal in a reverberatory furnace. Britain’s wrought-iron output multiplied in the decades that followed.

Topics: Furnaces, Casting & Rolling, puddling, wrought iron

Further reading: [Read more](https://en.wikipedia.org/wiki/Henry_Cort)

- Cort’s 1783 patent used grooved rolls to shape iron bars far faster than tilt hammers.
- In puddling, workers stirred molten pig iron in a coal-fired reverberatory furnace until the carbon burned out.
- Puddling was gruelling, skilled labour; puddlers became a powerful craft group in 19th-century ironworks.
- Joseph Hall’s “wet puddling” (c. 1830s) used iron-oxide fettling and cut iron losses substantially.

Later displaced by: Bessemer Process
Builds on: Darby’s Coke Smelting
Displaces: Finery Forge & Walloon Process, Bloomery Smelting
Later built on by: Krupp of Essen, Carnegie Steel, Continuous Wide Strip Mill

### Krupp of Essen (1811 onward)

Friedrich Krupp founded a works in Essen in 1811 to make English-style cast steel. Under his son Alfred, Krupp became a giant of railway materials and armaments.

Topics: Industry, Alloys, Germany, cast steel

Further reading: [Read more](https://en.wikipedia.org/wiki/Krupp)

- Friedrich Krupp set out in 1811 to replicate Sheffield crucible steel in Essen, struggling for years to succeed.
- Alfred Krupp exhibited a flawless crucible steel ingot of about two tonnes at the 1851 Great Exhibition in London.
- Krupp’s seamless steel railway tyre (1852) became a mainstay of the business.
- Krupp steel artillery made the firm Europe’s leading arms maker by the late 19th century.

Builds on: Huntsman’s Crucible Steel, Cort’s Puddling & Rolling
Later built on by: Thomas–Gilchrist Basic Process, Stainless Steel
Later displaced by: Continuous Casting

### Neilson’s Hot Blast (1828)

James Beaumont Neilson patented preheating the air blown into blast furnaces in 1828. Hot blast sharply reduced fuel consumption and let Scottish ironworks use raw coal and local blackband ironstone.

Topics: Fuel & Energy, Furnaces, Scotland, hot blast

Further reading: [Read more](https://en.wikipedia.org/wiki/James_Beaumont_Neilson)

- Neilson’s 1828 patent heated the blast in iron vessels before it entered the furnace.
- Hot blast cut the fuel needed per tonne of iron by roughly a third at first, and more as temperatures rose.
- With hot blast, Scotland’s blackband ironstone and raw coal fuelled a boom in Scottish pig iron.

Later built on by: Cowper Regenerative Stove
Builds on: Steam-Blown Blast Furnaces, Darby’s Coke Smelting

## Bulk Steel Age

### Bessemer Process (1856)

Henry Bessemer announced in 1856 that blowing air through molten pig iron burns out carbon and silicon, making steel in minutes without fuel. It was the first cheap process for mass-producing steel.

Topics: Furnaces, Metallurgy, converter, mass production

Further reading: [Read more](https://en.wikipedia.org/wiki/Bessemer_process)

- Bessemer described his process at the British Association meeting in Cheltenham in August 1856.
- Air blown through a converter oxidised impurities, and the heat of reaction kept the charge molten for a roughly 20-minute blow.
- Early licensees failed because the acid-lined converter could not remove phosphorus from common British ores.
- Göran Fredrik Göransson in Sweden achieved the first commercial success in 1858 using low-phosphorus pig iron.
- Bessemer steel rails, far more durable than iron, drove a rapid fall in steel prices and a railway boom.

Displaces: Cort’s Puddling & Rolling
Later built on by: Mushet’s Spiegeleisen & Tool Steel, Carnegie Steel, Thomas–Gilchrist Basic Process, Continuous Wide Strip Mill, Linz–Donawitz Oxygen Process, Continuous Casting
Later displaced by: Siemens–Martin Open Hearth
Builds on: Chinese Fining & Co-fusion Steel, Finery Forge & Walloon Process

### Mushet’s Spiegeleisen & Tool Steel (1856–1868)

Robert Forester Mushet showed that adding spiegeleisen, a manganese-rich pig iron, fixed the brittleness of Bessemer steel. In 1868 he introduced R. Mushet’s Special Steel, the first commercial tungsten alloy tool steel.

Topics: Alloys, Metallurgy, manganese, tungsten

Further reading: [Read more](https://en.wikipedia.org/wiki/Robert_Forester_Mushet)

- Spiegeleisen additions removed excess oxygen and restored carbon, curing the “red-short” brittleness of early Bessemer steel.
- Mushet’s patents lapsed through unpaid fees; Bessemer later paid him an annual pension.
- R. Mushet’s Special Steel (1868) hardened in air and cut metal faster than carbon tool steels.

Builds on: Bessemer Process, Noric Steel, Huntsman’s Crucible Steel
Later built on by: Hadfield Manganese Steel, High-Speed Steel

### Cowper Regenerative Stove (1857–1860)

Edward Alfred Cowper patented a hot-blast stove in 1857 that stored heat from burning furnace gas in brick checkerwork. Cowper stoves gave much hotter blast than iron-pipe heaters and remain standard at blast furnaces today.

Topics: Fuel & Energy, Furnaces, hot blast, regenerator

Further reading: [Read more](https://en.wikipedia.org/wiki/Edward_Alfred_Cowper)

- Waste blast-furnace gas heated a tall stack of refractory bricks, which then heated incoming air.
- Stoves worked in sets, alternating between heating on gas and heating the blast.
- Modern blast furnaces still use three or four Cowper-type stoves to supply blast above 1,000 °C.

Builds on: Neilson’s Hot Blast
Later built on by: Siemens–Martin Open Hearth

### Siemens–Martin Open Hearth (1857–1865)

Carl Wilhelm Siemens developed the regenerative gas furnace, and in 1865 Pierre-Émile Martin used it to make steel from pig iron and scrap. Slower but more controllable than Bessemer, the open hearth dominated world steelmaking for much of the 20th century.

Topics: Furnaces, Fuel & Energy, regenerative, scrap

Further reading: [Read more](https://en.wikipedia.org/wiki/Open-hearth_furnace)

- Siemens’ regenerative furnace preheated fuel gas and air in brick chambers to reach steelmaking temperatures.
- Pierre-Émile Martin produced open-hearth steel at Sireuil, France, in 1865 by melting pig iron with scrap.
- Heats of several hours allowed chemists to sample and adjust composition, giving more consistent steel.
- In the United States open-hearth output overtook Bessemer steel around 1908.

Displaces: Bessemer Process
Later displaced by: Linz–Donawitz Oxygen Process, Héroult Electric Arc Furnace
Builds on: Cowper Regenerative Stove, Huntsman’s Crucible Steel
Later built on by: Thomas–Gilchrist Basic Process, U.S. Steel, Backyard Furnaces, Youngstown “Black Monday”

### Carnegie Steel (1875–1901)

Andrew Carnegie opened the Edgar Thomson Works at Braddock, Pennsylvania, in 1875 to make Bessemer rails. Relentless cost-cutting and vertical integration from ore to rails made Carnegie Steel the world’s largest steel company.

Topics: Industry, Labor, Pittsburgh, vertical integration

Further reading: [Read more](https://en.wikipedia.org/wiki/Carnegie_Steel_Company)

- The Edgar Thomson Works, designed by Alexander Holley, began producing Bessemer rails in 1875.
- Carnegie integrated coke (through Henry Clay Frick), ore, shipping and mills to control costs end to end.
- Steelworkers typically worked 12-hour shifts, with a 24-hour “long turn” at each shift change.
- In 1901 Carnegie sold the company to J. P. Morgan for about $480 million.

Later built on by: Homestead Strike, Mesabi Range Iron Ore, U.S. Steel, Tata Iron and Steel
Builds on: Bessemer Process, Cort’s Puddling & Rolling
Later displaced by: Tata Iron and Steel, Steel Strike of 1919

### Thomas–Gilchrist Basic Process (1876–1879)

Sidney Gilchrist Thomas and his cousin Percy Gilchrist lined the Bessemer converter with basic dolomite and added lime, removing phosphorus into the slag. The process unlocked the vast phosphoric ores of Lorraine and fuelled German steel growth.

Topics: Metallurgy, Trade, phosphorus, basic lining

Further reading: [Read more](https://en.wikipedia.org/wiki/Sidney_Gilchrist_Thomas)

- A basic dolomite lining and lime flux let phosphorus be oxidised and captured in slag rather than attacking the lining.
- Trials were carried out at Blaenavon ironworks in Wales, and the process was publicised in 1879.
- Phosphate-rich “Thomas slag” was ground and sold as agricultural fertiliser.
- Basic steelmaking on Lorraine minette ore helped Germany overtake Britain in steel output in the 1890s.

Builds on: Bessemer Process, Siemens–Martin Open Hearth, Krupp of Essen
Later built on by: European Coal and Steel Community, Linz–Donawitz Oxygen Process

### Hadfield Manganese Steel (1882)

Robert Hadfield of Sheffield patented a steel with about 12–13% manganese in 1882. Extremely tough and work-hardening, it was one of the first true alloy steels.

Topics: Alloys, Metallurgy, Sheffield, mangalloy

Further reading: [Read more](https://en.wikipedia.org/wiki/Mangalloy)

- Hadfield found that around 12% manganese gave a tough, non-magnetic austenitic steel, contrary to expectations of brittleness.
- Its work-hardening surface suited rock crushers, railway crossings and excavator teeth.
- The British Brodie helmet of the First World War was pressed from Hadfield manganese steel.

Builds on: Mushet’s Spiegeleisen & Tool Steel
Later built on by: Stainless Steel

### Homestead Strike (1892)

A lockout at Carnegie’s Homestead Works near Pittsburgh in 1892 escalated into a gun battle between strikers and Pinkerton agents. The defeat of the Amalgamated Association crippled steel unionism in the US for four decades.

Topics: Labor, union, Pinkertons

Further reading: [Read more](https://en.wikipedia.org/wiki/Homestead_strike)

- Henry Clay Frick locked out workers after contract talks with the Amalgamated Association broke down.
- On 6 July 1892 strikers fought Pinkerton agents arriving by barge; several men on both sides were killed.
- The Pennsylvania state militia took control of the town and the mill reopened with non-union labour.

Builds on: Carnegie Steel
Later built on by: Steel Strike of 1919, Nucor & the Mini-Mill

### Mesabi Range Iron Ore (1890s onward)

The Merritt brothers opened Minnesota’s Mesabi Range in the early 1890s, where soft high-grade ore could be dug by steam shovel. Shipped across the Great Lakes, it fed the mills of Pittsburgh, Cleveland and Gary.

Topics: Trade, Industry, Minnesota, ore

Further reading: [Read more](https://en.wikipedia.org/wiki/Mesabi_Range)

- Mesabi’s soft hematite lay near the surface and was mined in vast open pits with steam shovels.
- Ore boats carried Mesabi ore from Duluth and Two Harbors to lower Great Lakes ports.
- As high-grade ore ran out, the range turned to pelletised taconite from the mid-1950s.

Builds on: Carnegie Steel
Later built on by: U.S. Steel
Later displaced by: Japan’s Steel Ascendancy

### High-Speed Steel (1898–1900)

Frederick Winslow Taylor and Maunsel White at Bethlehem Steel found that heating tungsten-chromium tool steel close to its melting point made it keep its hardness at red heat. Their high-speed steel caused a sensation at the 1900 Paris Exposition.

Topics: Alloys, Metallurgy, Bethlehem, tool steel

Further reading: [Read more](https://en.wikipedia.org/wiki/High-speed_steel)

- Taylor and White’s heat treatment let tools keep cutting while glowing red-hot.
- Demonstrations at the 1900 Paris Exposition showed cutting speeds several times higher than with older tools.
- The 18% tungsten, 4% chromium, 1% vanadium “T1” grade was standardised around 1910.

Builds on: Mushet’s Spiegeleisen & Tool Steel
Displaces: Huntsman’s Crucible Steel

### Héroult Electric Arc Furnace (1900–1907)

Paul Héroult built the first commercial direct electric arc furnace for steel at La Praz, France, in 1900. First used for high-grade alloy steels, the EAF later became the basis of scrap-recycling mini-mills.

Topics: Furnaces, Fuel & Energy, electric, EAF

Further reading: [Read more](https://en.wikipedia.org/wiki/Electric_arc_furnace)

- Héroult’s 1900 furnace at La Praz struck arcs from carbon electrodes directly onto the steel charge.
- The first US electric arc furnace started in 1907 at Halcomb Steel in Syracuse, New York.
- Precise temperature control made early EAFs ideal for tool and alloy steels.
- Today roughly 30% of the world’s crude steel is made in electric arc furnaces, largely from scrap.

Displaces: Huntsman’s Crucible Steel, Siemens–Martin Open Hearth
Later built on by: Stainless Steel, Nucor & the Mini-Mill, Stegra (H2 Green Steel)

### U.S. Steel (1901)

J. P. Morgan merged Carnegie Steel with Federal Steel and other firms to form the United States Steel Corporation in 1901. Capitalised at about $1.4 billion, it was the first billion-dollar corporation.

Topics: Industry, Trade, J. P. Morgan, trust

Further reading: [Read more](https://en.wikipedia.org/wiki/U.S._Steel)

- U.S. Steel, formed in 1901, controlled roughly two-thirds of American steel production at its start.
- The company built the city and works of Gary, Indiana, from 1906 on the shore of Lake Michigan.
- The Supreme Court declined to break up U.S. Steel in a 1920 antitrust ruling.

Builds on: Carnegie Steel, Mesabi Range Iron Ore, Siemens–Martin Open Hearth
Later built on by: European Coal and Steel Community, ArcelorMittal
Later displaced by: Nucor & the Mini-Mill, Japan’s Steel Ascendancy

### Tata Iron and Steel (1907–1912)

Following Jamsetji Tata’s plans, the Tata Iron and Steel Company was founded in 1907 and poured its first ingot at Sakchi, later Jamshedpur, in 1912. It became the cornerstone of India’s modern steel industry.

Topics: Industry, Trade, India, Jamshedpur

Further reading: [Read more](https://en.wikipedia.org/wiki/Tata_Steel)

- TISCO was founded in 1907 with capital raised from Indian investors.
- Tata introduced an eight-hour day in 1912 and later pioneered welfare provisions for its workers.
- Tata Steel acquired Anglo-Dutch Corus in 2007, the successor to British Steel.

Builds on: Carnegie Steel
Displaces: Carnegie Steel
Later built on by: Steel Strike of 1919, ArcelorMittal

### Stainless Steel (1912–1913)

In 1913 Harry Brearley in Sheffield cast a 12.8% chromium steel that resisted corrosion. Around the same time Krupp patented austenitic chromium-nickel steels, the basis of today’s 18/8 grades.

Topics: Alloys, Metallurgy, chromium, Brearley

Further reading: [Read more](https://en.wikipedia.org/wiki/Stainless_steel)

- Brearley was seeking erosion-resistant gun-barrel steel when he cast his chromium steel on 13 August 1913.
- Its first big market was “rustless” cutlery made in Sheffield.
- Krupp engineers Benno Strauss and Eduard Maurer patented austenitic chromium-nickel steel in 1912.
- At least about 10.5% chromium forms a thin self-healing chromium oxide film that protects the metal.

Builds on: Hadfield Manganese Steel, Huntsman’s Crucible Steel, Krupp of Essen, Héroult Electric Arc Furnace
Displaces: Damascus Blades

## Modern Integrated Mills

### Steel Strike of 1919 (1919–1920)

Some 350,000 steelworkers struck in September 1919 for union recognition and an end to the 12-hour day. The strike collapsed in January 1920, though public pressure led U.S. Steel to drop the 12-hour day in 1923.

Topics: Labor, AFL, twelve-hour day

Further reading: [Read more](https://en.wikipedia.org/wiki/Steel_strike_of_1919)

- Organised by an AFL committee including William Z. Foster, about 350,000 workers walked out in September 1919.
- Companies brought in strikebreakers and branded strikers as radicals; the strike ended in defeat in January 1920.
- U.S. Steel abandoned the 12-hour day in 1923 after a public campaign and presidential pressure.

Builds on: Homestead Strike, Tata Iron and Steel
Displaces: Carnegie Steel
Later built on by: Youngstown “Black Monday”

### Continuous Wide Strip Mill (1923–1926)

John B. Tytus developed the continuous wide hot-strip mill at Armco in Ashland, Kentucky, in the 1920s. Cheap, wide sheet steel fed the booming automobile and appliance industries.

Topics: Casting & Rolling, Industry, Armco, sheet steel

Further reading: [Read more](https://en.wikipedia.org/wiki/Rolling_(metalworking))

- Armco’s Ashland mill, started in 1923, rolled steel through a train of stands into long, wide strip.
- Wide strip and cold-rolled sheet made all-steel car bodies and household appliances affordable.
- Continuous mills displaced many skilled hand-rolling crews in older sheet mills.

Builds on: Cort’s Puddling & Rolling, Bessemer Process
Later built on by: Continuous Casting
Later displaced by: Nucor & the Mini-Mill

### European Coal and Steel Community (1951–2002)

Proposed in the 1950 Schuman Declaration and founded by the 1951 Treaty of Paris, the ECSC pooled the coal and steel industries of six European countries. It was the institutional seed of the European Union.

Topics: Trade, Industry, Europe, Schuman

Further reading: [Read more](https://en.wikipedia.org/wiki/European_Coal_and_Steel_Community)

- Robert Schuman proposed in 1950 placing French and German coal and steel under a common High Authority.
- The six members created a common market for coal and steel, removing tariffs and quotas.
- The Community later managed capacity cuts and production quotas during the 1970s–80s steel crisis.

Builds on: Thomas–Gilchrist Basic Process, U.S. Steel
Later built on by: ArcelorMittal, EU Carbon Border Adjustment
Later displaced by: Section 232 Steel Tariffs

### Linz–Donawitz Oxygen Process (1952–1953)

Austrian engineers at VÖEST in Linz started the first oxygen top-blown converter in 1952, building on Robert Durrer’s experiments. Basic oxygen steelmaking replaced the open hearth and now makes about 70% of the world’s steel.

Topics: Furnaces, Metallurgy, BOF, Austria

Further reading: [Read more](https://en.wikipedia.org/wiki/Basic_oxygen_steelmaking)

- Swiss metallurgist Robert Durrer’s trials with pure-oxygen blowing laid the groundwork for the LD process.
- The first LD converter went into operation at Linz in November 1952, followed by Donawitz in 1953.
- A lance blowing pure oxygen onto the melt made a heat in under an hour, versus many hours in an open hearth.
- Basic oxygen furnaces now produce around 70% of world crude steel.

Displaces: Siemens–Martin Open Hearth
Builds on: Bessemer Process, Thomas–Gilchrist Basic Process
Later built on by: POSCO, Japan’s Steel Ascendancy, China Becomes the Steel Giant

### Continuous Casting (1950s onward)

Continuous casting solidifies molten steel directly into slabs, blooms or billets instead of individual ingots. Pioneered for steel by Siegfried Junghans and commercialised in the 1950s, it raised yields and cut energy use dramatically.

Topics: Casting & Rolling, Junghans, Concast

Further reading: [Read more](https://en.wikipedia.org/wiki/Continuous_casting)

- Henry Bessemer had proposed casting steel between rotating rolls in the 1850s, but the idea was impractical then.
- Siegfried Junghans developed the oscillating mould that made continuous casting of steel workable.
- Skipping ingot casting and soaking pits raised metal yield by around 10% and saved reheating energy.
- By the 2010s about 96% of world crude steel was continuously cast.

Builds on: Bessemer Process, Continuous Wide Strip Mill
Displaces: Krupp of Essen
Later built on by: Nucor & the Mini-Mill, Japan’s Steel Ascendancy

### Direct Reduction (HYL & Midrex) (1957–1969)

Direct reduction turns iron ore into solid “sponge iron” using reformed natural gas instead of coke. Hylsa’s HYL process (Monterrey, 1957) and the Midrex shaft furnace (Portland, Oregon, 1969) made DRI a feedstock for electric arc furnaces.

Topics: Furnaces, Fuel & Energy, DRI, natural gas

Further reading: [Read more](https://en.wikipedia.org/wiki/Direct_reduced_iron)

- Hylsa in Monterrey, Mexico, began commercial direct reduction with its HYL process in 1957.
- The first Midrex shaft furnace started in Portland, Oregon, in 1969 and became the most widely used DRI technology.
- Reformed natural gas supplies hydrogen and carbon monoxide that strip oxygen from ore pellets below melting point.

Builds on: Bloomery Smelting
Displaces: Darby’s Coke Smelting
Later built on by: Nucor & the Mini-Mill, HYBRIT Fossil-Free Steel, Stegra (H2 Green Steel)

### Backyard Furnaces (1958–1959)

During the Great Leap Forward, Mao Zedong set a target of doubling China’s steel output in 1958, and millions of people built small backyard furnaces. Much of the iron produced was unusable, and the campaign diverted labour from farming on the eve of famine.

Topics: Industry, Environment, China, Great Leap Forward

Further reading: [Read more](https://en.wikipedia.org/wiki/Backyard_furnace)

- China’s 1958 target of 10.7 million tonnes of steel aimed to overtake Britain within years.
- Furnaces fed with household pots and tools produced low-quality pig iron largely unfit for use.
- Fuel demand led to extensive tree felling, and diverted labour worsened the Great Chinese Famine.

Builds on: Bloomery Smelting, Siemens–Martin Open Hearth
Later built on by: Baosteel

### Japan’s Steel Ascendancy (1950s–1970s)

Post-war Japan built large coastal integrated works using imported ore and coal and quickly adopted oxygen converters and continuous casting. The 1970 merger of Yawata and Fuji formed Nippon Steel, then the world’s largest steelmaker.

Topics: Industry, Trade, Japan, Nippon Steel

Further reading: [Read more](https://en.wikipedia.org/wiki/Nippon_Steel)

- The state-owned Yawata Steel Works began operating in 1901, founding Japan’s modern steel industry.
- Greenfield seaside works received imported ore and coking coal by large bulk carriers directly at their docks.
- Japanese mills adopted BOF converters and continuous casting faster than American and British rivals.
- Yawata Iron & Steel and Fuji Iron & Steel merged in 1970 to form Nippon Steel.
- Japan’s crude steel output exceeded 100 million tonnes in 1973.

Later built on by: POSCO, Baosteel
Builds on: Linz–Donawitz Oxygen Process, Continuous Casting
Displaces: Mesabi Range Iron Ore, U.S. Steel
Later displaced by: Youngstown “Black Monday”, China Becomes the Steel Giant

## Global & Green

### POSCO (1968–1973)

Pohang Iron and Steel Company was founded in 1968 under Park Tae-joon as a state-backed pillar of South Korea’s industrialisation. Its Pohang works fired its first blast furnace in 1973 and POSCO grew into one of the world’s most efficient steelmakers.

Topics: Industry, Trade, South Korea, Pohang

Further reading: [Read more](https://en.wikipedia.org/wiki/POSCO)

- POSCO was founded on 1 April 1968, partly financed with funds from Japan’s 1965 normalisation settlement.
- Pohang’s first blast furnace started in 1973, using Japanese technical assistance.
- The coastal Gwangyang works, begun in the 1980s, became one of the largest integrated mills in the world.

Builds on: Japan’s Steel Ascendancy, Linz–Donawitz Oxygen Process

### Nucor & the Mini-Mill (1969–1989)

Under Ken Iverson, Nucor opened a scrap-fed electric arc mini-mill in Darlington, South Carolina, in 1969. Its 1989 Crawfordsville plant brought thin-slab casting to flat products, and Nucor became America’s largest steelmaker.

Topics: Industry, Casting & Rolling, mini-mill, scrap

Further reading: [Read more](https://en.wikipedia.org/wiki/Nucor)

- Nucor’s Darlington mill (1969) melted scrap in electric furnaces to make bars for its own joist business.
- Non-union, with lean management and heavy production bonuses, Nucor kept labour costs per tonne low.
- Crawfordsville, Indiana (1989) was the first mill to cast thin slabs commercially for sheet steel.
- Mini-mills steadily took market share from integrated mills, first in bars and then in sheet.

Builds on: Héroult Electric Arc Furnace, Direct Reduction (HYL & Midrex), Continuous Casting, Homestead Strike
Displaces: Continuous Wide Strip Mill, U.S. Steel
Later displaced by: Youngstown “Black Monday”

### Youngstown “Black Monday” (1977)

On 19 September 1977 Youngstown Sheet and Tube announced the closure of its Campbell Works in Ohio, eliminating about 5,000 jobs. The day came to symbolise the collapse of the American integrated steel industry.

Topics: Labor, Industry, Rust Belt, deindustrialisation

Further reading: [Read more](https://en.wikipedia.org/wiki/Youngstown_Sheet_and_Tube)

- The Campbell Works closure announced on 19 September 1977 cost roughly 5,000 jobs at once.
- Ageing open-hearth plants, imports and mini-mill competition undercut Mahoning Valley mills.
- A coalition of workers and clergy tried, unsuccessfully, to reopen the works under community ownership.

Builds on: Siemens–Martin Open Hearth, Steel Strike of 1919
Displaces: Japan’s Steel Ascendancy, Nucor & the Mini-Mill

### Baosteel (1978–1985)

Construction of the Baoshan works near Shanghai began in December 1978 as a flagship of China’s reform and opening, with technology and assistance from Nippon Steel. Baosteel later merged with Wuhan Iron and Steel to form China Baowu, the world’s largest steelmaker.

Topics: Industry, Trade, China, Shanghai

Further reading: [Read more](https://en.wikipedia.org/wiki/Baosteel)

- Ground was broken in December 1978, the same month China launched its reform and opening policy.
- Nippon Steel supplied plant design and technical assistance modelled on its Kimitsu works.
- Baosteel and Wuhan Iron and Steel merged in 2016 to form China Baowu Steel Group.

Builds on: Japan’s Steel Ascendancy, Backyard Furnaces
Later built on by: China Becomes the Steel Giant

### China Becomes the Steel Giant (1996–2020)

China passed 100 million tonnes of crude steel in 1996 to become the largest producer, then expanded at an extraordinary pace. By 2020 it produced over a billion tonnes, more than half of the world’s steel.

Topics: Industry, Trade, China, overcapacity

Further reading: [Read more](https://en.wikipedia.org/wiki/Iron_and_steel_industry_in_China)

- In 1996 China’s output passed 100 million tonnes, overtaking Japan as the world’s largest producer.
- China produced over 1 billion tonnes of crude steel in 2020, more than half the world total.
- Overcapacity and exports fuelled trade disputes and anti-dumping duties in the 2010s.
- Most Chinese steel is still made in coal-based blast furnaces and oxygen converters, a major source of CO₂.

Builds on: Baosteel, Linz–Donawitz Oxygen Process
Displaces: Japan’s Steel Ascendancy
Later built on by: Section 232 Steel Tariffs, HYBRIT Fossil-Free Steel, EU Carbon Border Adjustment

### ArcelorMittal (2006)

Mittal Steel’s hostile takeover of Arcelor in 2006 created ArcelorMittal, the world’s largest steel company at the time. It capped a wave of global consolidation in a long-fragmented industry.

Topics: Industry, Trade, consolidation, Mittal

Further reading: [Read more](https://en.wikipedia.org/wiki/ArcelorMittal)

- Arcelor itself was formed in 2002 by merging Usinor, Arbed and Aceralia.
- Lakshmi Mittal’s 2006 hostile bid for Arcelor succeeded after a raised offer of about €26.9 billion.
- The merged company operated mills across Europe, the Americas, Africa and Asia.

Builds on: European Coal and Steel Community, Tata Iron and Steel, U.S. Steel

### HYBRIT Fossil-Free Steel (2016–2021)

SSAB, LKAB and Vattenfall launched HYBRIT in 2016 to replace coke with fossil-free hydrogen in iron ore reduction. In 2021 the pilot plant in Luleå delivered the first hydrogen-reduced steel to Volvo.

Topics: Environment, Fuel & Energy, hydrogen, Sweden

Further reading: [Read more](https://en.wikipedia.org/wiki/HYBRIT)

- Steelmaker SSAB, miner LKAB and utility Vattenfall formed the HYBRIT initiative in 2016.
- Hydrogen from fossil-free electrolysis reduces ore pellets, emitting water instead of CO₂.
- In 2021 the first fossil-free steel from the Luleå pilot was delivered to Volvo.
- Iron and steel account for roughly 7–9% of global CO₂ emissions, mostly from coke-fired blast furnaces.

Later built on by: Stegra (H2 Green Steel), EU Carbon Border Adjustment
Builds on: Direct Reduction (HYL & Midrex), China Becomes the Steel Giant
Displaces: Darby’s Coke Smelting

### Section 232 Steel Tariffs (2018)

In 2018 the United States imposed a 25% tariff on most steel imports under Section 232, citing national security. Trading partners retaliated, and quota and tariff deals followed with several countries.

Topics: Trade, tariffs, United States

Further reading: [Read more](https://en.wikipedia.org/wiki/Trump_tariffs)

- A 25% tariff on steel imports took effect in March 2018 under Section 232 of the Trade Expansion Act of 1962.
- The EU, Canada, Mexico and others responded with retaliatory tariffs on US goods.

Builds on: China Becomes the Steel Giant
Displaces: European Coal and Steel Community
Later built on by: EU Carbon Border Adjustment

### Stegra (H2 Green Steel) (2020 onward)

Founded in 2020 as H2 Green Steel, Stegra set out to build the first large-scale green steel plant at Boden in northern Sweden. It combines a large electrolyser, hydrogen direct reduction and electric arc furnaces in one site.

Topics: Environment, Industry, hydrogen, Boden

Further reading: [Read more](https://en.wikipedia.org/wiki/Stegra)

- H2 Green Steel was founded in 2020 and renamed Stegra in 2024.
- The Boden plant integrates hydrogen electrolysis, a DRI shaft furnace and EAFs powered by Nordic renewable electricity.
- Carmakers and other buyers signed advance offtake contracts for its low-carbon steel.

Builds on: HYBRIT Fossil-Free Steel, Héroult Electric Arc Furnace, Direct Reduction (HYL & Midrex)

### EU Carbon Border Adjustment (2023–2026)

The EU’s Carbon Border Adjustment Mechanism puts a carbon price on imports of steel and other emissions-intensive goods. Reporting began in October 2023, with financial obligations from 2026.

Topics: Environment, Trade, EU, carbon price

Further reading: [Read more](https://en.wikipedia.org/wiki/Carbon_Border_Adjustment_Mechanism)

- CBAM covers iron and steel, aluminium, cement, fertilisers, hydrogen and electricity imports.
- A transitional reporting phase began on 1 October 2023; importers must buy certificates from 2026.
- It mirrors the EU Emissions Trading System so that free allowances for European steelmakers can be phased out.

Builds on: European Coal and Steel Community, HYBRIT Fossil-Free Steel, Section 232 Steel Tariffs, China Becomes the Steel Giant