The old BS1470 standard has been replaced by nine EN standards:
EN485-1: Technical conditions for inspection and delivery
EN485-2: Mechanical Properties
EN485-3: Tolerances for HOT Rolled Material
EN485-4: Tolerances for COLD Rolled material
EN515: Temper Designations
EN573-1: Numerical alloy designation system
EN573-2: Chemical symbol designation system
EN573-3: Chemical Compositions
EN573-4: Product forms in different alloys
For those familiar with the old BS1470 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.
• Mechanical Properties – Similar but not identical. Also, 0.2% Proof Stress must now be quoted on test certificates.
• Thickness Tolerances – Considerably tighter for alloys 1050A & 3103. To reflect manufacturing difficulty the tolerances for alloys 5251, 5083 & 6082 are now wider than this, although still a little tighter than in BS1470.
• Length and Width Tolerances – These tend to be tighter and are now all on the plus side (i.e. minus zero).
• Flatness Tolerances – These are considerably tighter.
Please note that thickness tolerances for Cold Rolled material vary according to Alloy, with the Alloys falling into two groups as shown below.
|Alloy Group I|
|1080A, 1070A, 1050A, 1200|
|3003, 3103, 3005, 3105|
|Alloy Group II|
|2014, 2017A, 2024|
|5040, 5049, 5251, 5052, 5154A, 5454, 5754, 5182, 5083, 5086|
|7020, 7021, 7022, 7075|
Thickness Tolerances - Cold Rolled Sheet & Strip
Please note that thickness tolerances for Cold Rolled material vary according to Alloy, with the Alloys falling into two groups as shown above.
The thickness tolerances also vary according to the width of the maetrial as shown in the tables below.
|Thickness mm||Tolerance (+/-)mm||Tolerance (+/-)mm||Tolerance (+/-)mm|
|Group I 1000mm wide||Group I 1250mm wide||Group I 1500mm wide|
|0.2 to 0.4||0.02||0.04||0.05|
|0.51 to 0.60||0.03||0.05||0.06|
|0.61 to 0.80||0.03||0.06||0.07|
|0.81 to 1.0||0.04||0.06||0.08|
|1.1 to 1.2||0.04||0.07||0.09|
|1.21 to 1.50||0.05||0.09||0.10|
|1.51 to 1.80||0.06||0.10||0.11|
|1.81 to 2.0||0.06||0.11||0.12|
|2.1 to 2.5||0.07||0.12||0.13|
|2.6 to 3.0||0.08||0.13||0.15|
|3.1 to 3.5||0.10||0.15||0.17|