Mild steels have a low carbon content, typically under 0.25%, and are best suited to applications that do not involve heavy loads or stresses. Their easy workability and weldability make them ideal for a range of fabricated products.
Carbon steels, such as En8 and En9 are generally suitable for applications requiring added strength and superior tensile properties to mild steel.
Where greater strength is required, alloy steels such as En19 and En24, with specific alloying elements such as nickel or chromium added, make them suitable for a variety of highly stressed applications.
Steel Standards & Specifications
Although there are literally hundreds of specifications relating to steels, most steel users in practice will come across a relatively small number of specifications as part of their work. The En designation was replaced by a six digit system when the BS 970 was revised in 1970, e.g 080A15. This code is constructed as detailed below :
The first three symbols are a number code indicating the type of steel :
000 - 199
Carbon & carbon-manganese steels. The number represents the manganese content x 100.
200 - 240
Free cutting steels. The second and third number indicate the sulphur content x 100.
Silicon Manganese Valve Steels.
300 - 499
Stainless and heat resisting steels.
500 - 999
The fourth symbol is a letter code :
Steel is supplied to a chemical composition determined by analysis of the batch sample.
Steel is supplied to a hardenability specification.
Steel is supplied to a Mechanical Property specification.
Steel is a stainless steel.
The fifth and sixth symbol is a number representing the actual mean carbon x 100.
For further details and typical uses of certain specifications , please click on this link: http://www.tamworthsteel.co.uk/steel-specifications/technical-information/