Guides / Materials
6061 or 7075 for drone frame parts, and where each one belongs
September 14, 2026
Both alloys weigh the same. That surprises people who have read that 7075 is the high performance choice. The density difference between 6061-T6 and 7075-T6 is under one percent, so swapping one for the other in an identical part saves nothing at all. This comparison is one part of our guide to drone parts materials, which covers every alloy and polymer on the airframe.
What changes is how much material the part needs.
The numbers that matter
| Property | 6061-T6 | 7075-T6 | Why it matters on a UAV |
|---|---|---|---|
| Yield strength | about 276 MPa | about 503 MPa | A clamp in 7075 can be thinner for the same grip load |
| Tensile strength | about 310 MPa | about 572 MPa | Margin on lugs, hinges and landing gear |
| Density | 2.70 g/cm3 | 2.81 g/cm3 | Effectively the same |
| Elastic modulus | about 69 GPa | about 72 GPa | Nearly identical, so stiffness comes from geometry, not alloy |
| Weldable | Yes | No, not for flight parts | Decides most housing and bracket designs |
| Corrosion resistance | Good | Fair, needs coating | Agricultural and marine aircraft care a lot |
| Relative material cost | Baseline | Roughly 1.5 to 2 times | Small next to machining time on a complex part |
The modulus line is the one engineers miss. Stiffness is almost identical between the two. If a plate is flexing, a stronger alloy will not fix it, a rib or a thicker web will.
Where 7075 earns its money
- Arm and boom clamps. The clamp has to close on a tube without crushing it and hold under vibration. 7075 lets the clamp body be thin without yielding around the screw bosses.
- Landing gear legs, feet and hinge parts. These take the impact loads. Yield strength is the whole point.
- Lugs, shackles and pip pin bosses. Small parts carrying concentrated load.
- Anything with a thin section carrying bending. The extra yield lets you remove material.
Where 6061 is the better answer
- Center and top plates. Loads are spread, the geometry sets the stiffness, and you may want to weld or bond something to it later.
- Housings, covers and battery trays. Corrosion resistance and clean anodising matter more than yield.
- Heat sinks and cold plates. 6061 conducts heat better than 7075, about 167 W per metre kelvin against about 130.
- Anything welded. 7075 is not weldable for flight parts. Design in 6061 and heat treat after welding.
Machining and cost, honestly
7075 machines well, often better than 6061 because it produces shorter chips and leaves a cleaner surface in a thin wall. On a small part the machining time is similar, so the extra cost is mostly the bar or plate itself, and on a complex part material is a minority of the price anyway.
Where 7075 does add cost is protection. It really does need anodising on exposed parts, and hard anodise on a bore means masking or machining undersize because the coating grows the surface.
A part by part answer
| Part | Pick | Reason |
|---|---|---|
| Arm or boom clamp | 7075-T6, hard anodised | Thin section under clamp load |
| Center plate | 6061-T6 | Stiffness comes from geometry, may need welding or bonding |
| Motor mount plate | 6061-T6 | Bolt circle accuracy matters more than yield |
| Landing gear leg or foot | 7075-T6 | Impact load |
| ESC or flight controller housing | 6061-T6 | Corrosion, anodise quality, possible welding |
| Heat sink | 6061-T6 | Thermal conductivity |
| Gimbal bracket | 6061-T6 normally, 7075 if thin | Depends on section |
| Hinge pin or clevis | 7075-T6 or titanium | Concentrated load, wear |
One more option
If a part is at the limit of 7075 and weight still matters, the next step is titanium Grade 5, not a thicker aluminium part. It costs more to buy and more to cut, but on a small highly loaded fitting the weight saved is real, and it does not set up a galvanic couple against carbon fibre the way aluminium does.
The capabilities page lists what we keep on the shelf, and the buyer guide covers what to tolerance once the material is chosen.
See also: aluminium specifications on drone drawings for how to call out the alloy, temper and specification.
Frequently asked questions
Is 7075 lighter than 6061?
No. Both alloys weigh about 2.80 g per cubic centimetre, within one percent of each other. 7075 saves weight only because its higher strength lets you use less material in a loaded part. In an unloaded part it saves nothing and costs more.
Can you weld 7075?
Not in any way you should fly. 7075 is not considered weldable by conventional fusion methods because the weld zone cracks and loses temper. If a part has to be welded, design it in 6061 and heat treat after welding.
Does 7075 need anodising?
It needs protection. 7075 has noticeably worse corrosion resistance than 6061, particularly at the surface, so hard anodise or at least type II anodise it on anything exposed to weather, spray or salt.
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