The strip mill was a major innovation in
steelmaking
Steelmaking is the process of producing steel from iron ore and carbon/or scrap. In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur and excess carbon (the most important impurity) are removed from the sourced iron, and allo ...
, with the first being erected at
Ashland, Kentucky
Ashland is a list of Kentucky cities, home rule-class city in Boyd County, Kentucky, Boyd County, Kentucky, United States. The largest city in Boyd County, Ashland is located upon a southern bank of the Ohio River at the state border with Ohio a ...
in 1923. This provided a continuous process, cutting out the need to pass the plates over the rolls and to double them, as in a
pack mill. At the end the strip was cut with a
guillotine shear or rolled into a coil. Early (
hot rolling
In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. The concept is simi ...
) strip mills did not produce strip suitable for tinplate, but in 1929
cold rolling
In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. The concept is simi ...
began to be used to reduce the gauge further. The first strip mill in the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
was opened at
Ebbw Vale
Ebbw Vale (; cy, Glynebwy) is a town at the head of the valley formed by the Ebbw Fawr tributary of the Ebbw River in Wales. It is the largest town and the administrative centre of Blaenau Gwent county borough. The Ebbw Vale and Brynmawr con ...
in 1938 with an annual output of 200,000 tons.
The strip mill had several advantages over pack mills:
* It was cheaper due to having all parts of the process, starting with
blast furnace
A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheric p ...
s on the same site.
* Softer steel could be used.
* Larger sheets could be produced at lower cost and this reduced cost and enabled tinplate and steel sheet to be used for more purposes.
* It was capital intensive, rather than labour-intensive.
An Advanced type of such mill is now in production called " CSP Mill", where caster & Mill are an integral system saving lot of energy and fuel.
Steelmaking
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