Alloys / 7075-T6 / T73

7075-T6 / T73 Aluminum

Close to double the yield strength of 6061 for the same weight. The alloy to reach for when a part is bending or yielding, not when it needs to be cheap.

What it is

7000 series, aluminum-zinc-magnesium-copper. T6: peak strength. T73: overaged on purpose, giving up some strength for real resistance to stress corrosion cracking.

Machining

Machines almost as fast as 6061 and holds a good finish, so the strength does not come with a machining penalty. It does not forgive a poor fixture on thin sections, since it is less forgiving of chatter than the softer 6000 series.

Finishing and joining

Does not weld with conventional processes, the zinc and copper content make it prone to hot cracking. Anodizes to a visibly darker, less even shade than 6061 and is more prone to stress corrosion, which is the reason T73 exists as a deliberate trade-off.

Where it turns up

Loaded arms, uprights and clamps
Aerospace-grade structural brackets
Tooling and fixtures under repeated load

Read further

The full comparison against 6061Read the guide
Why the alloy premium matters most on parts that are mostly swarfRead the guide

At a glance

Yield strength	503 MPa
Density	2.81 g/cm³
Weldability	1 / 5
Anodizing	2 / 5
Corrosion resistance	2 / 5
Strength for weight	5 / 5
Stays flat	2 / 5
Machinability	4 / 5

Scores run 1 to 5, editorial judgements for comparison, not measured values. Yield is a typical published figure for this temper, not a guarantee for your lot.

Get 7075-T6 / T73 quoted

Full property table for all alloys: alloy selector.

Questions

Is 7075-T6 / T73 weldable?

Not with conventional welding processes. 7075 is prone to cracking or loses most of its strength in the heat-affected zone, so a welded assembly needs a different alloy for that joint.

Does 7075-T6 / T73 anodize evenly?

Not reliably. Expect a less even, sometimes darker or patchier result than 6061 in the same anodizing tank, so treat any anodized finish on this alloy as functional rather than cosmetic.