Definition
The property of a metal that allows it to be deformed by compression — such as rolling, hammering, or pressing — into a new shape without cracking or breaking.
Plain English
How well a metal can be squeezed or pounded into a new shape without splitting. A malleable metal can be flattened into thin sheets; a non-malleable metal would crack apart if you tried.
Context Anchor
Seen in aircraft materials, sheet metal work, and maintenance discussions about forming or repairing metal parts.
Derivation
From the Latin malleus, meaning 'hammer.' Literally, 'able to be hammered.' The word still carries that exact meaning in metalwork — a malleable metal is one you can hammer into shape.
Why Pilots Care
Aircraft skin, cowlings, and many formed parts depend on malleable metals like aluminum that can be pressed into curved shapes without fracturing. Knowing a metal is malleable tells you it can be worked and repaired by forming rather than only by cutting and welding.
Analogy
Modeling clay is malleable because you can press it into a new shape without it breaking. A dry cracker is not malleable; if you press it, it cracks.
Intuition Check
Malleability does not simply mean soft. It means the material can be permanently shaped under force without cracking.
Example Sentence 1
Aluminum's high malleability is one reason it is used for aircraft skin — it can be rolled into thin sheets and formed over curved surfaces without cracking.
Example Sentence 2
When repairing a dented access panel, the technician takes advantage of the metal's malleability to restore its original shape.