Differences Between BS & EN Standards
For those familiar with the old BS1474 it is useful to highlight where the new EN standards differ:
- Chemical Compositions – No Change.
- Alloy Numbering System – No Change.
- Temper Designations for Heat Treatable Alloys – A new wider range of special tempers having up to four digits after the T have been introduced for non- standard applications (e.g. T6151).
- Temper Designations for Non Heat Treatable Alloys – No change to existing tempers but a more comprehensive definition of how tempers are achieved.
- Soft (O) temper is now classified H111 and an intermediate temper H112 is introduced.
- For alloy 5251 tempers are now shown as H32/H34/H36/H38 (equivalent to H22/H24, etc). H19/H22 & H24 are now shown separately.
Chemical Compositions: Please refer to the datasheet entitled Aluminium Specifications.
Mechanical Properties: Please refer to the datasheet entitled Aluminium Specifications.
For the purposes of tolerances, in the following tables the alloys are split into two groups:
- Group I – 1000 series, 3000 series, 6000 series, 5005, 5051, 5251
- Group II – 2000 series, 7000 series, 5052, 5154, 5454, 5754, 5083, 5086