6061 and 6082 aluminium — EN AW-6061 / EN AW-6082

6061 and 6082 are heat-treatable aluminium–magnesium–silicon alloys of the 6xxx series. 6082 is the European workhorse: Hydro and Aalco both name it the alloy most commonly used for general machining in plate form. 6061 is the closely related alloy found in American specifications such as AMS-QQ-A-250/11. In T6, solution heat-treated and artificially aged, their minimum proof strength is more than twice that of T4.

Designations

Most sources give 3.3211 for 6061; a few give 3.3214. The European standards are EN 573-3 for composition (current edition 2026), EN 755-2 for extrusions (2025), EN 485-2 for sheet and plate (2016+A1:2018) and EN 515 for tempers (2017). The property values on this page are as producers and stockists reproduce them, from earlier editions; whether EN 755-2:2025 changed any of them could not be checked.

Chemical composition

EN 573-3 limits, % by mass. Single values are maximums. The Estonian standards body notes that the EN 573-3 limits are identical to those registered with the Aluminum Association.

EN AW-6082EN AW-6061

The two windows exclude each other. 6061 needs at least 0.15 % copper, where 6082 allows at most 0.10 %; and 6082 needs at least 0.40 % manganese, where 6061 allows at most 0.15 %. No melt can be certified to both, so a 6082 certificate does not cover a drawing that calls for 6061, or the reverse.

Tempers

The temper code after the alloy says how the material was processed. The digit after T describes the heat treatment; 51 means the material was stretched to relieve the stresses left by quenching. The 7075 page shows what those stresses do to a machined part.

OT4T5T6T651T6511

THeat treatedThermally treated to a stable temper other than F, O or H.

6Artificially agedSolution heat-treated, then artificially aged.

51StretchedStress-relieved by stretching after solution treatment. Permanent set 1½–3 % for plate, 1–3 % for rod, bar and extruded shapes.

Solution treatment→Quench→Stretch→Artificial ageing

T6510 is stretched with no further straightening. Hydro also makes producer tempers: T64, underaged for formability, and T66, a T6 with special process control and higher properties.

Mechanical properties

Extrusions

EN 755-2 minimums, except where marked maximum. HB values are typical, for information only.

The 6082 values agree across Hydro, Aalco, Wieland and BIKAR; the 6061 T6 rows are from BIKAR, Wieland and Euralliage, the T4 and O rows from BIKAR and Euralliage. For hollow 6082 profiles Hydro’s data sheet stops the 5–25 mm band at 15 mm, while Hydro’s declaration of performance and Aalco extend it to 25 mm. Where a profile spans more than one band, the lowest value applies to the whole section (Hydro). Euralliage gives 14 and 12 % elongation for 6061-T4 bar.

Rp0.2Rm

Drawn bar to EN 754-2, up to 80 mm, is 255 / 310 MPa for 6082-T6 and 240 / 290 MPa for 6061-T6, 30 MPa more tensile strength than extruded 6061 (Wieland, Euralliage).

Sheet and plate

EN 485-2 minimums for T6 (sheet) and T651 (plate).

Values in MPa. 6082 rows from BIKAR, Aalco and Righton Blackburns, with Eurocode 9 agreeing up to 100 mm; 6061 rows from BIKAR, with Eurocode 9 agreeing up to 80 mm. In thin sheet 6082 is the stronger alloy; from 12.5 mm upward the two have the same minimum proof strength. BIKAR alone lists thicker plate: 6082 230 / 275 MPa (150–175 mm) and 220 / 260 MPa (175–350 mm); 6061 230 / 265 MPa (150–250 mm).

US limits and typical values

The Aluminum Association’s limits for extrusions (Aluminum Standards and Data, 2009) are 35 ksi (241 MPa) yield and 38 ksi (262 MPa) tensile for 6061-T6, and 38 ksi (262 MPa) and 45 ksi (310 MPa) for 6082-T6 from 0.200 to 6.000 in. For 6061-T6 sheet, AMS-QQ-A-250/11 asks for 35 ksi yield and 42 ksi (290 MPa) tensile. The MPa values are converted here.

Minimums are what a certificate guarantees; typical values are what the material usually shows. The Aluminum Association’s typical values for 6061-T6 are Rp0.2 276 MPa, Rm 310 MPa, 95 HB, shear strength 207 MPa and fatigue strength 96.5 MPa at 5 × 10⁸ cycles (MatWeb). For 6082-T6, Aalco’s 2013 data sheet gives 290 MPa and 340 MPa.

Physical properties

European producers give 70 GPa; the Aluminum Association gives 68.9 GPa for 6061, the average of tension and compression. Hydro and Euralliage print 2.71 g/cm³ for 6082. The expansion coefficient varies by source, so the table gives the spread. Aalco, Smiths and other stockists of the same lineage give 555 °C as the melting point of 6082; Hydro and Euralliage give a solidus of 575 °C. The 6082 conductivity is from Euralliage and is consistent with Hydro’s data sheet; MatWeb gives 167 W/(m·K) for 6061-T6.

Two numbers in this table change how a part is machined:

• Thermal expansion. From the coefficients, a 100 mm length of aluminium grows about 0.023 mm for a 10 K rise, twice the 0.011 mm of C45E. A part measured warm off the machine is oversize.
• Elastic modulus. At 70 GPa against 210 GPa for C45E, a wall of the same shape deflects three times as much under the same cutting force. Thin walls and long overhangs need lighter cuts or support.

Heat treatment

Ageing schedules from MatWeb and Total Materia; natural ageing time from BIKAR only. BIKAR gives a general T6 window of 155–190 °C for 4–16 h for both alloys, and an annealing range of 380–420 °C. Extrusions can reach T4 and T6 properties by quenching at the press, without a separate solution treatment (Hydro, Wieland).

6082 needs a fast quench. Nowak and co-workers write that alloys such as EN AW-6082 require high cooling rates, and Hydro notes that T6 may not always be available because of the alloy’s quenching limits. Additions of chromium and manganese raise the quench sensitivity of 6xxx alloys (Assaad).

Welding

Both alloys weld well by MIG and TIG; Wieland and BIKAR rate them 1 for MIG, 2 for TIG and 3 for gas and resistance welding, on a scale where 1 is very good. 4043 is the usual filler for 6082 (Aalco, BlueScope), with 5356 as the alternative (BlueScope). The price is strength: the weld heat dissolves or coarsens the precipitates next to the weld, and Eurocode 9 (EN 1999-1-1) gives reduced design values for this heat-affected zone (HAZ).

Strengths in MPa; ρ is the HAZ value divided by the parent value. Values from the 2007 text of EN 1999-1-1, in its Ukrainian adoption, with beamdimensions.com agreeing for the extrusions; the plate row is from the adoption only, and later amendments were not checked. Eurocode 9 states that these values hold for MIG welding up to 15 mm thickness; thicker material needs a further reduction unless other data are available. *So the plate row applies as printed only from 12.5 to 15 mm.

6082-T6, 0.2 % proof strength fo6082-T6, tensile strength fu6082-T4, 0.2 % proof strength fo

Hydro notes that welded 6061 can be heat-treated and artificially aged again to restore its strength.

Anodizing

Both alloys anodize very well for protection and only moderately for decoration: Wieland and BIKAR rate protective anodizing 1 and decorative anodizing 3. Hydro rates 6082 at 2 for decorative anodizing on a 1–5 scale, against 5 for 6060 and 6063, and puts this down to its manganese. 6082 still takes clear, dyed and hard anodic coatings (Hydro).

Machining

Aluminium is ISO 513 group N. ISCAR’s group 22, hardenable wrought aluminium at 100 HB, uses kc1.1 = 800 N/mm² and mc = 0.25; the non-hardenable group 21 at 60 HB uses 700 N/mm². At h = 0.2 mm that gives 800 × 0.2^−0.25 ≈ 1196 N/mm², less than half the value for austenitic stainless steel. Shapes by Hydro puts the cutting force in aluminium at about a third of that in steel. No second tool maker’s kc table for these alloys could be found; read cutting forces before using the figure.

Machine them hard, not soft. Wieland and BIKAR rate both alloys 4 when annealed and 2 when age-hardened (1 = very good). Soft material builds up on the insert, makes long chips and leaves burrs; Shapes by Hydro advises machining at the highest practical temper, and notes that chips break more easily as strength rises. Aalco reports that 6082-T6 makes tight coils of swarf with a chip breaker. Lukasak (Sapa) rates 6082 good in T5 and T6 and 6061 only adequate in T6 and T6511, with chips that are harder to break, and recommends chip breakers or peck drilling for both.

Built-up edge is the typical tool problem, worst in soft tempers (Shapes by Hydro). Sandvik Coromant’s remedy is a higher cutting speed, to raise the temperature, and sharp edges with a smooth rake face; Lukasak adds a finely ground edge and advises against ceramics.

Speeds are high. Wieland gives 400–800 m/min for 6082, without naming the tool. TaeguTec’s PCD turning grades run from 300 up to 2000–2500 m/min in aged wrought aluminium, and Shapes by Hydro defines high-speed machining of aluminium as 2500 m/min and upward.

Coolant. Tungaloy calls for emulsion when machining aluminium with its PCD cutters; Seco rates its uncoated H15 and H25 and coated F15M milling grades for dry or wet cutting.

Choosing between them

• Strength. 6082-T6 is the stronger in extrusions up to 150 mm and in sheet up to 12.5 mm; in thicker plate the minimum proof strength is the same, 240 MPa.
• Machining. Aalco rates 6082 good and 6061 acceptable; Hydro and Aalco name 6082 the plate alloy for general machining.
• Specification. The compositions exclude each other, so the drawing decides. US documents such as AMS-QQ-A-250/11 specify 6061.
• Anodizing and welding. Both weld well and lose about half their proof strength next to the weld; neither is a first choice for decorative anodizing.

Typical uses are similar: structural beams and bridges, cranes, scaffolding, rail and road vehicles, and machined plate parts for 6082 (Hydro, Aalco); shipbuilding, rail coaches, truck frames, military bridges and screw-machine parts for 6061 (Aalco, Hydro).