6061 vs 7075 aluminum: which grade for your part?

6061 is the weldable, corrosion-resistant workhorse; 7075 is aerospace-strength and about triple the cost. When the strength-to-weight actually earns 7075, and when 6061 is the right call.

Quick answer: 6061-T6 is the aluminum workhorse: weldable, corrosion-resistant, machinable and cheap. 7075-T6 is far stronger (approaching some steels by strength-to-weight) but it does not weld, it corrodes faster, and it costs roughly two to three times as much. Spec 7075 only when the strength-to-weight number genuinely earns it (aerospace structure, high-stress parts). For almost everything else, 6061 is the right grade and the cheaper one.

They are not the same alloy with a different number

6061 is the general-purpose alloy you reach for by default. 7075 is a high-strength aerospace alloy with real trade-offs: it will not weld, it corrodes more readily, and it costs a multiple of 6061. You buy 7075 for one reason, strength-to-weight, and you pay for it everywhere else.

When 7075 actually earns it

When the part is strength- or weight-critical and cannot be redesigned around it: aircraft structure, high-load fittings, competition and defence parts where every gram counts. If a stress analysis says 6061 will not carry the load at an acceptable weight, that is when 7075 is worth the premium and the handling.

When 6061 is the right call (most of the time)

General machined parts, enclosures, brackets, and anything that gets welded. 7075 is not 6061 with more muscle: if your part gets welded, 7075 is off the table before you start, because it does not weld. Redesign in 6061 or fasten mechanically. For most jobs, 6061 gives you strength, corrosion resistance and weldability for a third of the cost.

Finishing: both anodize

Both grades anodize, and hard anodize (Type III) adds wear resistance for moving parts. 7075's lower corrosion resistance is one more reason to anodize it. See anodizing for the finish, and aluminum welding if the 6061 part is a weldment.

What to send for a quote

Your part, the grade (or the load and weight target, and we will flag the grade), quantity and finish. Request quotes from Canadian shops that machine aluminum daily.

FAQ

What is the difference between 6061 and 7075?

7075 is much stronger but does not weld, corrodes faster and costs two to three times more. 6061 is weaker but weldable, corrosion-resistant, cheaper and easier to machine. Most parts want 6061.

Is 7075 worth the extra cost?

Only when strength-to-weight is critical and the part cannot meet it in 6061. For general and structural work, 6061 is the better value.

Can you weld 7075 aluminum?

Not readily. It is prone to cracking and loses properties in the weld zone, so it is generally joined mechanically. If your part must be welded, design it in a weldable grade like 6061 or 5052.

Which aluminum is best for aerospace?

7075 (and 2024) for structure where strength-to-weight rules; 6061 for general aerospace parts and anything welded. The airframe uses both, chosen feature by feature.

Does aluminum corrode?

Yes, though it forms a protective oxide. 7075 corrodes more readily than 6061, which is why aerospace 7075 parts are usually anodized or coated.

Last reviewed: July 2026. Related reading: 304 vs 316 stainless steel and aluminum welding.