7075-T6 aluminium properties
An Al-Zn-Mg-Cu alloy and the strongest aluminium in common commercial use. It was developed for airframe structure, and most loaded tooling is still made from it.
- AlloyAl-Zn-Mg-Cu (7000 series), with zinc as the main alloying element and copper for strength
- TempersT6 · T651 (stress-relieved plate) · T73 / T7351 where stress-corrosion cracking is the risk
- StandardsASTM B209 plate · ASTM B221 extrusion · JIS A7075P · EN AW-7075
- Density2.81 g/cm³, a touch heavier than 6061 and still about a third of steel
- TensileAround 570 MPa typical in T651 plate; ASTM B209 minimum is 524 MPa
- YieldAround 500 MPa typical; ASTM B209 minimum is 448 MPa
- HardnessAbout 150 HB, more than half again as hard as 6061-T6
- MachinabilityCuts well and chips break cleanly. Residual stress in the stock causes more trouble than the cutting does
- WeldingConventional TIG or MIG welds crack, so design for fasteners
- CorrosionLower than 6061 bare. Anodise or alclad where the part sees weather
Buy T651, not T6, for anything flat. 7075 carries more locked-in stress than 6061. Plate that hasn't been stretch-relieved will bow visibly once the first pocket is cut. On symmetrical parts we also rough both faces before finishing either one, which costs an extra setup.
7075 grade equivalents
| Grade | JIS (Japan) | US (ASTM / AISI / UNS) | GB/T (China) | EN / DIN (Europe) | Cross-reference |
|---|---|---|---|---|---|
| 7075-T6 bar and extrusion | A7075P · A7075BE (JIS H4000 / H4040) | 7075-T6 · UNS A97075 · ASTM B209 / B221 | 7075 (GB/T 3190; old LC4) | EN AW-7075 · 3.4365 | Standard equivalent |
| 7075-T651 stress-relieved plate | A7075P-T651 | 7075-T651 · ASTM B209 | 7075-T651 | EN AW-7075 T651 | Standard equivalent |
| 7075-T7351 overaged, SCC resistant | A7075P-T7351 | 7075-T7351 · ASTM B209 | 7075-T7351 | EN AW-7075 T7351 | Standard equivalent |
| 7050-T7451 thick-section alternative | No exact JIS grade | 7050-T7451 · UNS A97050 · AMS 4050 | 7050 (GB/T 3190) | EN AW-7050 | Check the MTC |
Designations taken from JIS H4000 and H4040, ASTM B209 and B221, GB/T 3190 and the EN AW numbers. We list 7050 because US aerospace drawings often call for it in plate over about 75 mm. It's a separate alloy and not a temper of 7075, and we treat the two as different materials. Last reviewed 13 September 2026.
When the extra cost earns itself
Loaded fixtures and tooling
Clamping plates, lifting fixtures, aerospace ground-support tooling, blow-mould bodies. Where a 6061 fixture would have to get thicker to survive the load, 7075 gives you the strength back without adding weight.
Parts where weight is the specification
When a steel part has to be converted to aluminium and still carry the same load, 7075-T6 is usually the only aluminium that can do it. For lighter duty, 6061 is cheaper and quicker to get.
Not for welded assemblies
Conventional fusion welding does not work on 7075, because the weld cracks as it solidifies. For a welded assembly, either the design changes to fasteners or the material changes to 6061.
Not for bare outdoor service
It resists corrosion less well than 6061, and in the T6 temper it can suffer stress-corrosion cracking under sustained tensile load. T73 or T7351 gives up some strength to fix that. The choice belongs on the drawing, so let us know which temper your design needs.
Not the automatic aerospace answer
For plate thicker than roughly 75 mm, US drawings often specify 7050-T7451, since it keeps its properties deeper into the section. It's a different alloy. If your print says 7050 we quote 7050, including the cost to source it here.
Watch out for the tapped hole
7075 threads better than 6061, but it still galls against stainless fasteners when a joint is assembled again and again. On a fixture that gets rebuilt, put a steel thread insert on the drawing. The insert will outlast the aluminium around it.
Machining process
The cutting itself is straightforward. The hard part with 7075 is getting a flat, stable part out of a stressed billet, and that gets decided in the process plan before the first cut is made.
- MillingFANUC RoboDrill plus Doosan, Haas and Hision machining centres, in 3, 4 and 5-axis
- TurningMori Seiki and Okuma lathes to Ø 310 × 800 mm
- ToolingPolished-flute carbide, high positive rake. Chips break shorter and cleaner than in 6061
- StressRough both faces, release the clamps, then finish. On tall thin ribs we split the job across two days
- CoolantFlood, and plenty of it. Heat that goes into a thin 7075 wall shows up as a bow after unclamping
- FixturingLight clamping on finish passes. If force is what holds a part flat, it springs as soon as it comes off the table
- ThreadsCut or rolled, metric and inch. Steel inserts where the joint is opened and closed repeatedly
- InspectionMitutoyo CRYSTA-APEX V CMM in a climate-controlled lab, reported in inch and millimetre
We hold these figures day to day, but they aren't a blanket specification. On a large thin plate, flatness depends more on the stock than on the machine. General tolerance follows ISO 2768 fine or medium class, whichever your print calls. Send the drawing and we'll confirm what we can hold before you commit to a PO.
Compatible finishing processes
- Anodise IIIType III hard anodise, typically 25–50 μm, and the usual choice on tooling
- Anodise IIType II clear and black, where the part is not a wear surface
- ConversionChemical conversion coating (chromate class), where anodising is not wanted
- BlastingBead blast before anodising for a uniform matte
- MarkingLaser marking for part number, revision and lot
- Not forAnything requiring a welded joint. No finishing process will repair a cracked 7075 weld
Hard anodise on 7075 is not cosmetic. The coating comes out darker and less even than on 6061, and the colour changes from batch to batch. If appearance matters, tell us and we'll quote Type II over a bead-blast base instead. Coating growth is about half the thickness per surface. A 50 μm hardcoat will close a bore by roughly 50 μm on diameter, so mark it wherever it lands on a fit. Full finishing list →
Ordered in, not stocked
- StockNot held in Vietnam. We buy it in per job, in plate or bar as the part needs
- Lead timeProcurement time is added on top of our standard 14 days after PO and confirmed in the quote
- TemperTell us T6, T651, T73 or T7351 at RFQ stage. They're priced and sourced separately
- SectionThick plate is the hardest size to get quickly. Send the raw stock size you need with the drawing
- QuoteWithin 24 business hours of a complete RFQ
- CertificateEN 10204 3.1 mill certificate on request, with a dimensional report in inch and millimetre
We buy 7075 per job, so the lead time comes with the quotation. If your programme has a fixed date, put it in the RFQ and we'll confirm whether we can meet it before you place the order. We never substitute 6061 for 7075 without your written approval.
Common questions
How much stronger is 7075-T6 than 6061-T6?
Roughly twice the yield strength (about 500 MPa against about 275 MPa typical) at almost the same density. That's the main reason to pay for it.
Can you weld 7075?
Not by conventional TIG or MIG. The weld cracks as it solidifies. If the design needs joining, we'll recommend fasteners or a move to 6061 at quote stage.
Do you stock 7075 in Vietnam?
No. We order it in per job, which adds procurement time on top of our standard 14 days after PO. We confirm the actual figure when we quote.
What is the difference between T6, T651 and T7351?
T651 is T6 plate that has been stretched to relieve residual stress, and it's the one to specify for anything flat. T7351 is overaged. It gives up a little strength and resists stress-corrosion cracking much better. In service they behave as different materials, so the drawing should name one.
Can 7075 be hard anodised?
Yes, and Type III is the normal finish on 7075 tooling. Expect a darker and less even colour than on 6061, and allow for coating growth of about half the thickness per surface where it sits on a fit.
My drawing says 7050. Can you use 7075 instead?
No, not without your written approval. 7050 is a separate alloy chosen for thick sections. It's not a temper of 7075. We quote what the print calls for, including the cost to source it in Vietnam.
Which is cheaper overall, a thicker 6061 part or a 7075 part?
Often the 6061 part, once the procurement time is priced in. Send both the load case and the envelope with the RFQ and we'll give you the two prices side by side.
Related information
6061-T6 aluminium
The default machining grade. Stocked in Vietnam, weldable, and the right choice unless the load says otherwise.
Aluminium grade equivalents
All six grades we run, cross-referenced across JIS, ASTM, GB and EN, with what is stocked here.
Finishing and heat treatment
Type II and Type III anodising, plus the plating and coating we specify and check before shipping.