– Why must certain products and parts be made with non-recycled metals?

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I have heard that certain things, like aircraft parts, must be made from non-recycled aluminum. Why is that? Isn’t recycled aluminum melted down and impurities removed?

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Mostly because of quality and safety.

Recycled parts – not just metal but plastic, rubber, and everything else recycled – tends to be a little more “rough around the edges”.

As a case in point, I was contracted to work with a company once making syringes and medical rubber devices for parts of the syringe. They *could* have used recycled plastic and rubber for the syringe – but they wouldn’t, as that would mean the syringe’s plug would be lower quality, prone to leaks, the plastic case wouldn’t be as durable and prone to cracking, and overall it’d be a product that no hospital or doctor would buy because there’d be an implicit risk of the thing breaking that came entirely from using recycled materials.

Airplane parts are no different here – it’s a very high precision machine and the tolerance ranges (as in, +/- X amount of millimeters on a part) are very tight. If they use recycled materials, the tolerance range *just from using recycled materials* is going to be wider, the material will be more prone to breaking down, and it’d be a pretty big safety risk for the airplane simply because of using recycled materials.

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It would be more than OK to use recycled materials on products that aren’t going to have very severe consequences if the product catastrophically fails.

I mean that in the sense that, for something like a newspaper, using recycled paper material is fine because if the material fails, it’s just a news paper, no one’s life is at risk because a newspaper tears apart easier. No one’s life is at risk when a soda can uses recycled aluminum.

But it’s not like that for an airplane – it’s a machine that is dependent on it’s quality of parts to ensure safety. One over-stressed part made of recycled material potentially puts everyone on board’s life at risk.

I’ve never heard of a ban on recycled materials in aircraft. As long as the material meets specifications, I don’t see why it wouldn’t be acceptable. That’s one nice thing about metals. The recycled version can be identical to version from raw ore.

Sometimes they’re identical *and* cheaper, because some metals are very expensive to purify from raw ore.

I will note that typically aircraft aluminum is a very different alloy than other products like soda cans would use. This difference in alloying metals may be the source of what you’ve heard. They could still use recycled aluminum, but it would take more processing to create an aerospace grade alloy out of that raw material.

Also, these days substantial parts of airplanes are going to be various composites, not metals. These planes are going to be harder to recycle, because you can’t just melt them down. That’s not a problem yet, because the planes we’ve retired are decades old and these composite planes are new, but it will eventually need a solution.