Technical Specifications

Aluminium Alloy // General Information

The old BS1474 - 1987 standard has been replaced by a number of EN standards of which the most important are:


EN754 - Cold drawn rod, bar & tube
EN755 - Hot extruded products
EN12020 - Extruded precision profiles in alloys 6060 & 6063
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 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.


Note that for the purposes of tolerances 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

Alloy Groups

Alloy Group I
1050, 1070, 1200, 1350, 3102, 3003, 3103
5005, 5005A, 5051A, 5251
6101A, 6101B, 6005, 6005A, 6106, 6008, 6010A, 6012, 6014, 6018, 6023, 6351, 6060, 6360,
6061, 6261, 6262, 6262A, 6063, 6063A, 6463, 6065, 6081, 6082, 6182
Alloy Group II
2007, 2011, 2011A, 2014, 2014A, 2017A, 2024, 2030
5019, 5049, 5052, 5154A, 5454, 5754, 5083, 5086
7003, 7005, 7108, 7108A, 7020, 7021, 7022, 7049A, 7075

Diameter Tolerances - Round Bar

Diameter mmTolerances mm (+/-)Tolerances mm (+/-)
Group IGroup II
8 to 180.220.30
19 to 250.250.35
26 to 400.300.40
41 to 500.350.45
51 to 650.400.50
66 to 800.450.70
81 to 1000.550.90
101 to 1200.651.0
121 to 1500.801.2
151 to 1801.01.4
181 to 2201.151.7
221 to 2701.32.0
271 to 3201.62.5

Dimensional Tolerances - Square Bar

Width Across Flats (mm)Tolerances mm (+/-)Tolerances mm (+/-)
Group IGroup II
10 to 180.220.30
19 to 250.250.35
26 to 400.300.40
41 to 500.350.45
51 to 650.400.50
66 to 800.450.70
81 to 1000.550.90
101 to 1200.651.0
121 to 1500.801.2
151 to 1801.01.4
181 to 2201.151.7

Dimensional Tolerances - Hexagon Bar

Width Across Flats (mm)Tolerances mm (+/-)Tolerances mm (+/-)
Group IGroup II
10 to 180.220.30
19 to 250.250.35
26 to 400.300.40
41 to 500.350.45
51 to 650.400.50
66 to 800.500.70
81 to 1000.550.90
101 to 1200.651.0
121 to 1500.801.2
151 to 1801.01.4
181 to 2201.151.7

Width Tolerance - Rectangular Bars

Width Across Flats (mm)Tolerances mm (+/-)Tolerances mm (+/-)
Group IGroup II
10 to 180.250.35
19 to 300.300.40
31 to 500.400.50
51 to 800.600.70
81 to 1200.801.0
121 to 1801.01.4
181 to 2401.41.8
241 to 3501.82.2
351 to 4502.22.8
451 to 6003.03.5

Squareness Tolerances - Rectangular Bar

Width Across Flats (mm)Max Deviation from Square (mm)
2 to 100.1
11 to 1000.01 x Width Across Flats
101 to 1801.0
181 to 2401.5

Squareness Tolerances - Square Bars

Width Across Flats (mm)Max Deviation from Square (mm)
10 to 1000.01 x Width across Flats
101 to 1801.0
181 to 2201.5

Max Corner Radii - Square Bars

Width Across Flats (mm)Tolerances mm (+/-)Tolerances mm (+/-)
Group IGroup II
10 to 251.01.5
26 to 501.52.0
51 to 802.03.0
81 to 1202.53.0
121 to 1802.54.0
181 to 2203.55.0

Thickness Tolerances for Rectangular Bar - Group I

Width Across Flats (mm)Tols +/-Tols +/-Tols +/-Tols +/-Tols +/-
2-6mm6.1 - 10mm 10.1-18mm19-30mm31-50mm
10 to 180.200.250.25--
19 to 300.200.250.300.3-
31 to 500.250.250.300.350.4
51 to 800.250.300.350.400.5
81 to 1200.300.350.400.450.6
121 to 1800.400.450.500.550.6
181 to 240-0.550.600.650.7
241 to 350-0.650.700.750.8
351 to 450--0.800.850.9
451 to 600----0.9

Thickness Tolerances for Rectangular Bar - Group I

Width Across Flats (mm)Tols +/-Tols +/-Tols +/-Tols +/-
51-80mm81-120mm121-180mm181-240mm
10 to 18----
19 to 30----
31 to 50----
51 to 800.6---
81 to 1200.70.8--
121 to 1800.70.91.0-
181 to 2400.81.01.21.4
241 to 3500.91.11.31.5
351 to 4501.01.21.41.6
451 to 6001.01.4--

Thickness Tolerances for Rectangular Bar-Group II

Width Across Flats (mm)Tols +/-Tols +/-Tols +/-Tols +/-Tols +/-
2-6mm6.1-10mm10.1-18mm19-30mm31-50mm
10 to 180.250.300.35--
19 to 300.250.300.400.40-
31 to 500.300.300.400.50.5
51 to 800.300.350.450.60.7
81 to 1200.350.400.50.60.7
121 to 1800.450.500.550.70.8
181 to 240-0.600.650.70.9
241 to 350-0.700.750.80.9
351 to 450--0.91.01.1
451 to 600----1.2

Thickness Tolerances for Rectangular Bar-Group II

Width Across Flats (mm)Tols +/-Tols +/-Tols +/-Tols +/-
51-80mm81-120mm121-180mm181-240mm
10 to18----
19 to 30----
31 to 50----
51 to 800.7---
81 to 1200.81.0--
121 to 1801.01.11.4-
181 to 2401.11.31.61.8
241 to 3501.21.41.71.9
351 to 4501.41.82.12.3
451 to 6001.41.8--

Diameter Tolerances for Smls & Porthole Round Tube

Diam. (mm) OD or IDMax Deviation of Mean Diam. Max Dev. at Any Point mmMax Dev. at Any Point mmMax Dev. at Any Point mm
mm (+/-)Not Annealed or Heat TreatedHeat-TreatedAnnealed
8 to 180.250.40.61.5
19 to 300.300.50.71.8
31 to 500.350.60.92.2
51 to 800.400.71.12.6
81 to 1200.600.91.43.6
121 to 2000.901.42.05.0
201 to 3501.41.93.07.6
351 to 4501.92.84.010.0

Wall Thickness Tols for Seamless Round Tube

Wall Thickness (mm)Tolerance Measured at any Point (+/- %)
0.5 to 3.010
3.0 to 5.09
Over 5.08

Tol - Width,Depth,Width A/F for Smls & P/Hole Tube

Width, Depth or Width A/FOvality Tols (+/-mm)Ovality Tols (+/-mm)Ovality Tols (+/-mm)Ovality Tols (+/-mm)
Group I 0 to 100mmGroup I 101 to 200Group I 201 to 300Group I 301 to 350
Up to 100.250.300.350.40
11 to 250.300.400.500.60
26 to 500.500.600.800.90
51 to 1000.700.901.101.30
101 to 150-1.101.301.50
151 to 200-1.301.501.80
201 to 300--1.702.10
301 to 350---2.80

Tol - Width,Depth,Width A/F for Smls & P/Hole Tube

Width, Depth or Width A/FOvality Tols (+/-mmOvality Tols (+/-mmOvality Tols (+/-mmOvality Tols (+/-mm
Group II 0 to 100mmGroup II 101 to 200mmGroup II 201 to 300mmGroup II 301 to 350mm
Up to 100.400.500.550.60
11 to 250.500.700.800.90
26 to 500.800.901.01.20
51 to 1001.01.201.301.60
101 to 150-1.501.701.80
151 to 200-1.902.202.40
201 to 300--2.502.80
301 to 350---3.50

Tols on WT for SMLS Tube - other than Round Tube

Wall Thickness (mm)Tols (+/-mm) for given Circumscribing CircleTols (+/-mm) for given Circumscribing CircleTols (+/-mm) for given Circumscribing Circle
Up to 100mm Group I101 to 300mm Group I301 to 350mm Group I
0.5 to 1.50.250.35-
1.51 to 3.00.300.500.75
3.1 to 6.00.500.751.0
6.1 to 100.751.01.2
11 to 151.01.21.5
16 to 201.51.92.0
31 to 301.92.22.5
31 to 40-2.52.7

Tols on WT for SMLS Tube - other than Round Tube

Wall Thickness (mm)Tols (+/-mm) for given Circumscribing CircleTols (+/-mm) for given Circumscribing CircleTols (+/-mm) for given Circumscribing Circle
Up to 100mm Group II101 to 300mm Group II301 to 350mm Group II
0.5 to 1.50.350.50-
1.51 to 3.00.450.650.9
3.1 to 6.00.600.901.2
6.1 to 101.01.31.5
11 to 151.31.71.9
16 to 201.92.22.5
21 to 302.22.73.1
31 to 40---

Wall Thickness Tolerances for Porthole Round Tube

Wall Thickness (mm)Tolerance Measured at Any Point (+/- %)
3.07
3.0 to 5.06
Over 5.05

Tols on WT for P/hole Tube - Other Than Round Tube

Wall Thickness (mm)Tols (+/-mm) for given Circumscribing CircleTols (+/-mm) for given Circumscribing CircleTols (+/-mm) for given Circumscribing Circle
Up to 100mm Group I101 to 300mm Group I301 to 350mm Group I
0.5 to 1.50.200.30-
1.51 to 3.00.250.400.60
3.1 to 6.00.400.600.80
6.1 to 10.00.600.801.0
11 to 150.801.01.2
16 to 201.21.51.7
21 to 301.51.82.0
31 to 40-2.02.0

Tols on WT for P/hole Tube - Other Than Round Tube

Wall Thickness (mm)Tols (+/-mm) for given Circumscribing CircleTols (+/-mm) for given Circumscribing CircleTols (+/-mm) for given Circumscribing Circle
Up to 100mm Group II101 to 300mm Group II301 to 350mm Group II
0.5 to 1.50.300.40-
1.51 to 3.00.350.500.70
3.1 to 6.00.550.700.90
6.1 to 100.751.01.2
11 to 151.01.31.5
16 to 201.51.82.0
21 to 301.82.22.5
31 to 40-2.53.0

This Data is indicative only and as such is not to be relied upon in place of the full specification. In particular, mechanical property requirements vary widely with temper, product and product dimensions. All information is based on our present knowledge and is given in good faith. No liability will be accepted by the Company in respect of any action taken by any third party in reliance thereon.

Please note that the 'Datasheet Update' date shown above is no guarantee of accuracy or whether the datasheet is up to date.

The information provided in this datasheet has been drawn from various recognised sources, including EN Standards, recognised industry references (printed & online) and manufacturers’ data. No guarantee is given that the information is from the latest issue of those sources or about the accuracy of those sources.

Material supplied by the Company may vary significantly from this data, but will conform to all relevant and applicable standards.

As the products detailed may be used for a wide variety of purposes and as the Company has no control over their use; the Company specifically excludes all conditions or warranties expressed or implied by statute or otherwise as to dimensions, properties and/or fitness for any particular purpose, whether expressed or implied.

Advice given by the Company to any third party is given for that party’s assistance only and without liability on the part of the Company. All transactions are subject to the Company’s current Conditions of Sale. The extent of the Company’s liabilities to any customer is clearly set out in those Conditions; a copy of which is available on request.

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