Cadmium plated bolts and aircraft fittings.

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g-strk
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Cadmium plated bolts and aircraft fittings.

Post by g-strk » Sun Feb 07, 2021 10:14 am

Cadmium plated bolts and aircraft fittings.

Many aircraft bolts and fittings are Cadmium plated. A while ago I heard that it is not a good idea to have direct contact with cadmium. So I did a bit of reading.

What is the LAA’s view on this ?

Now, leaving out radiation control, the features that make cadmium attractive are: good corrosion resistance, solderability, cathodic protection of steel, galvanic compatibility with aluminum, excellent lubricity, freedom from stick-slip when torquing, malleability, economy, and no gummy and voluminous corrosion products.

Most cadmium plated bolts -- and most zinc plated bolts as well -- also have hexavalent chromate conversion coatings on them, and hexavalent chromate is another toxin.

Cadmium is considered a hazardous material, so don't touch it with bare skin as part of regular work duties.

So I think the short answer is you should be wearing gloves if handling them and certainly don’t hold a bolt with your lips, as a 3rd hand, even for a moment while assembling a part.

As a follow up is the use of stainless steel fittings a better solution to corrosion resistance for bolts, nuts and turnbuckles ?
Erik Hadley
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Ian Melville
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Re: Cadmium plated bolts and aircraft fittings.

Post by Ian Melville » Sun Feb 07, 2021 12:34 pm

Not an LAA view,

IIRC On an Aluminium structure there is an increased risk of corrosion with stainless steel fittings, more so with magnetic stainless steel(Type 410), which is not a recommended as a fastener on aluminium parts.

You would also need to match the specification of the original fittings.

Suggest you speak with LAA Engineering first.
Ian Melville
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Nick Allen
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Re: Cadmium plated bolts and aircraft fittings.

Post by Nick Allen » Tue Feb 09, 2021 4:52 pm

As a (very) general rule, a solid metal isn't going to poison you unless you work with them a lot/try very hard.

Powders are bad -- you inhale them (so be careful sawing/filing).

Vapours are bad -- you inhale them too (so welding is a hazard).

Solutions are bad because the metals are in an ionic and hence potentially reactive state.

But I wouldn't loose any sleep handling the occasional cadmium-plated nut/bolt. (Different matter if I was working in the factory doing the cadmium plating.)

Ian Melville
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Re: Cadmium plated bolts and aircraft fittings.

Post by Ian Melville » Tue Feb 09, 2021 7:47 pm

Don't lick your nuts :lol:
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Gerry Holland
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Re: Cadmium plated bolts and aircraft fittings.

Post by Gerry Holland » Wed Feb 10, 2021 1:12 pm

028138

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