Definition
A soft, silvery-white metallic element used in aviation primarily as a protective plating on steel hardware to prevent corrosion. Cadmium plating is commonly applied to bolts, nuts, and other steel fasteners, giving them a characteristic dull silver or slightly yellowish appearance.
Plain English
A metal used as a thin protective coating on steel aircraft parts to stop them from rusting. You see it most often on bolts and nuts, where it gives the metal a soft silver finish.
Context Anchor
Seen in aircraft maintenance, hardware identification, corrosion control, and references to cadmium-plated steel parts.
Derivation
From the Latin cadmia, meaning 'calamine' (a zinc ore), because cadmium was first discovered as an impurity in zinc ores. Knowing this hints at why cadmium behaves like zinc in plating -- both protect steel from corrosion in similar ways.
Why Pilots Care
Cadmium-plated hardware is standard on aircraft, and recognizing it helps in identifying correct replacement parts. Using the wrong type of plated hardware can lead to corrosion or galvanic reactions between dissimilar metals.
Intuition Check
Do not think of cadmium as a part or fastener by itself. In aircraft maintenance, it is usually the protective metal coating on another metal part.
Example Sentence 1
The mechanic replaced the corroded bolt with a new cadmium-plated one of the same size and grade.
Example Sentence 2
During overhaul, all steel fittings were replaced with new parts finished in cadmium for added protection.