Classifying steel

There are several thousand steel and alloy-steel grades - all of which have different chemical compositions. In addition, there are all the different possible heat treatments, cold forming conditions, shapes and surface finishes that can make classification of these products difficult.

However, steels can be classified reasonably easily into a few major groups according to their chemical composition, applications, shapes and surface conditions.Chemical composition - steels can be grouped into one of the three following classes:carbon steels,low-alloy steels,high-alloy steels

All steels contain a small amount of incidental elements (such as manganese, silicon, aluminium, phosphorus, sulphur and copper) left over from the steel-making process. As these elements together normally constitute less than 1 per cent of the steel, they are not considered alloys.


Carbon steels are the most produced and widely used, accounting for about 90 per cent of global steel production. These are grouped into:high-carbon steels (with carbon content above 0.5 per cent),medium-carbon steels (with 0.2 to 0.49 per cent carbon),low-carbon steels (with 0.05 to 0.19 per cent carbon),extra-low-carbon steels (with 0.015 to 0.05 per cent carbon),ultra-low-carbon steels (with less than 0.015 per cent carbon)