6061-T6 aluminium properties
An Al-Mg-Si alloy. It can be heat treated and welded, and it cuts cleanly. Western and Japanese buyers both treat it as their general structural aluminium.
- AlloyAl-Mg-Si (6000 series), alloyed with magnesium and silicon, heat treatable
- TempersT6 (solution treated and artificially aged) · T651 (T6 plus stretch stress-relief on plate)
- StandardsASTM B209 plate · ASTM B221 extrusion · JIS A6061P / A6061BE · EN AW-6061
- Density2.70 g/cm³, about a third of the weight of steel for the same volume
- Tensile290 MPa minimum for T6 plate to ASTM B209; typically around 310 MPa
- Yield240 MPa minimum; typically around 275 MPa
- HardnessAbout 95 HB in T6. Soft enough to cut fast and still hard enough to hold a thread
- MachinabilityFree cutting. What limits the cycle is chip control rather than tool wear
- WeldingTIG and MIG weldable, though the heat-affected zone loses its T6 condition
- CertificateMill test certificate to EN 10204 3.1 on request
T6 and T651 are not the same stock. T651 is plate that has been stretched after ageing to take the residual stress out. Specify T651 if your part is a flat plate machined on both faces, or a frame that has to stay flat after heavy pocketing. T6 plate will bow in that situation. Fixturing on our side cannot remove stress that's already in the material.
6061 and the grades it gets confused with
| Grade | JIS (Japan) | US (ASTM / AISI / UNS) | GB/T (China) | EN / DIN (Europe) | Cross-reference |
|---|---|---|---|---|---|
| 6061-T6 bar, extrusion, plate | A6061P · A6061BE (JIS H4000 / H4040) | 6061-T6 · UNS A96061 · ASTM B209 / B221 | 6061 (GB/T 3190; old LD30) | EN AW-6061 · 3.3211 | Standard equivalent |
| 6061-T651 stress-relieved plate | A6061P-T651 | 6061-T651 · ASTM B209 | 6061-T651 | EN AW-6061 T651 | Standard equivalent |
| 6082-T6 the European stock grade | No exact JIS grade | No US twin, so do not read it as 6061 | 6082 (GB/T 3190) | EN AW-6082 · 3.2315 | Check the MTC |
| 6063-T5 the extrusion finish grade | A6063S (JIS H4100) | 6063 · UNS A96063 | 6063 (old LD31) | EN AW-6063 | Standard equivalent |
Designations taken from JIS H4000, H4040 and H4100, ASTM B209 and B221, GB/T 3190 and the EN AW numbers. All four systems share the 6000-series numbering, so 6061 on a drawing means the same thing in each of them. 6082 is different. It's a European grade and has no clean US or JIS twin. Last reviewed 13 September 2026.
When it's right, and when it's not
Use it for general machined parts
Manifolds, brackets, housings, jigs and fixtures, structural frames, plates and adapters. Unless the drawing has a reason to call for another grade, 6061-T6 is nearly always the right answer and the cheapest one.
Not for cosmetic anodised parts
After anodising, 6061 comes out a little cloudy and greyer than 6063, and extrusion lines show up more easily. For a part that's visible on the finished product, 6063 is the grade made for the job. Switching changes the mechanical properties, which makes it an engineering decision. We'll raise it with you and wait for written approval.
Not for a heavily loaded fixture
If a clamp, a lifting plate or an aerospace ground-support fixture carries real load, look at 7075-T6, which has roughly twice the yield strength. It costs more and we order it in for the job instead of holding stock, so please tell us at RFQ stage and not after the drawing is released.
Not for sheet metal that gets bent
6061-T6 cracks on a tight bend radius. Formed enclosures, chassis and folded brackets should be 5052-H32. That grade is not heat treatable; it gets its strength from work hardening.
6082 is not a drop-in for 6061
European mills stock 6082 where Asian and US mills stock 6061. It's slightly stronger, uses manganese where 6061 uses chromium, and anodises differently. If your drawing says 6082 and the local market only has 6061, the substitution needs your written approval.
Effect of welding on the T6 temper
Around a weld, the heat-affected zone falls back towards T4 condition. It stays there unless the whole assembly is re-solution-treated, and we don't offer that. So if the part is welded and the drawing still asks for T6 properties across the joint, let's talk about it before we quote.
Machining process
6061 is easy to cut. Where jobs go wrong is finish and flatness, and those come down to fixturing and getting the chips out of the cut. Tool choice matters much less.
- MillingFANUC RoboDrill tapping centres plus Doosan, Haas and Hision machining centres, in 3, 4 and 5-axis
- TurningMori Seiki and Okuma lathes to Ø 310 × 800 mm, including twin-spindle
- ToolingPolished-flute carbide, 2 and 3 flute, uncoated or ZrN, with high rake and wide chip gullets
- CoolantFlood coolant, through-spindle where the tool allows. Most bad 6061 finishes we see come from built-up edge
- Thin wallRough, release, then finish in a second setup. On thin plate we leave the part overnight between operations rather than chase the bow afterwards
- ThreadsCut or rolled, metric and inch series. Aluminium threads gall, so for an assembly that's taken apart often, specify a steel thread insert
- DeburringHand deburr as standard. If edge break matters, put it on the drawing. A 0.1 mm break and a 0.3 mm break make different parts
- InspectionMitutoyo CRYSTA-APEX V CMM in a climate-controlled lab, reported in both inch and millimetre
We hold these figures day to day on this grade. They're not a blanket specification. General tolerance follows ISO 2768 fine or medium class, whichever your print calls. For anything tighter than the numbers above, send the drawing and we'll confirm whether we can hold it before you commit to a PO.
Compatible finishing processes
- Anodise IIType II clear and black
- Anodise IIIType III hard anodise, typically 25–50 μm
- BlastingBead blast before anodising where the drawing calls for a uniform matte
- ConversionChemical conversion coating (chromate / Alodine class)
- PlatingElectroless nickel, where a harder or solderable surface is needed
- MarkingLaser marking for part number, revision and lot
- CoatingPowder coating to the colour and finish your drawing names
Anodising grows the part. About half the coating thickness builds outward on each surface. A 50 μm hard anodise therefore adds around 25 μm per side and closes a bore by about 50 μm on diameter. Where the anodise lands on a fit, a bearing seat or a threaded hole, mark it on the drawing and we'll machine to allow for it. That costs less than masking afterwards. Full finishing list →
Stock and lead time
- PlateStocked in Vietnam in 6061-T651, common thicknesses
- BarStocked, round and flat bar in T6
- ExtrusionAvailable; profile sections confirmed at quote
- Ordered inOversized plate, unusual thicknesses and specific tempers add lead time on top of standard
- QuoteWithin 24 business hours of a complete RFQ
- Lead timePrototype 3–7 days · small batch 7–14 days · standard 14 days after PO
- CertificateEN 10204 3.1 mill certificate on request, with a dimensional report in inch and millimetre
Stock moves, so we confirm availability and section size in the quote. We don't substitute a grade or a temper without your written approval, and that includes the standard equivalents listed above.
Common questions
What is the difference between 6061-T6 and 6061-T651?
The alloy is identical. T651 is plate that has been stretched after ageing to remove residual stress. For a part machined on both faces, or any flat plate that has to stay flat, specify T651. T6 plate will move as you cut into it.
Is A6061 the same as 6061?
Yes. The leading A and the trailing letter are a JIS convention for product form. A6061P is plate and A6061BE is extruded bar. The alloy is the same 6061 you would buy to ASTM B209 or EN AW-6061.
Can you machine 6082 instead if 6061 is easier to get?
Not without your written approval. 6082 is a European grade with different alloying and slightly higher strength, and it anodises differently. We confirm what is available in Vietnam in the quote.
How tight a tolerance can you hold on 6061?
Routinely ±0.01 mm on milling and ±0.005 mm on turning, and Ra 0.4 μm is achievable on turned surfaces. Beyond that it depends on the feature and the part geometry. Send the print and we'll give you a specific answer for that part.
Can you anodise the parts?
Yes. Type II clear and black and Type III hard anodise. Plating, powder coating and conversion coating are also available, and the coating spec is checked before shipping.
Will anodising change my dimensions?
Yes, and more so as the coating gets thicker. Roughly half the coating thickness grows outward on each surface. Call out the anodise on the drawing wherever it lands on a fit and we'll machine undersize to suit.
Do you supply mill certificates for aluminium?
Yes. We supply EN 10204 3.1 material test certificates on request, along with the dimensional inspection report in both inch and millimetre.
Related information
7075-T6 aluminium
Roughly twice the yield strength of 6061, ordered in rather than stocked, and not weldable by conventional methods.
Aluminium grade equivalents
All six grades we run, cross-referenced across JIS, ASTM, GB and EN, with what is stocked in Vietnam.
Finishing and heat treatment
Anodising in Type II and Type III, black oxide, plating and every heat treatment condition we specify.