In 1941, the EN range of steel specifications was first introduced as the War Emergency Numbering. This was also known as the British Standard Schedule BS970.
The ‘Technical Advisory Committee’ of the ‘Special & Alloy Steels Committee’, aided the British Standards Institute who then published 58 steel specifications (EN1 to EN58). According to the chemical composition, the different grades of steel were arranged sequentially starting with low carbon grades EN1, EN2, and EN3, working up to stainless steel grades EN56, EN57 and EN58. When further steel grades were developed, the BS970 EN range of steel specifications was revised in 1955 to add these additional grades.
Unfortunately, the 1941 edition made no allowance for possible insertion of further steel grades. The British Standards Institution decided that to have applied for a high EN number would have divorced the grades completely from steels of similar types.
Therefore numerous grades’ suffix letters were added (for example EN17 became EN17A, EN17B, and EN17C). The revision of the standard BS970 in 1955 increased the number of specifications to nearly 200.
Many EN steel grades are now obsolete. The most common grades of supply are as follows;
Carbon Steel Alloy Steel Spring Steel – EN3, EN14, EN43, EN6, EN16, EN16T, EN45, EN8, EN19, EN19T, EN47, EN9, EN24, EN24T, EN26, EN26V, EN26W and EN30B.