malleable

adj. flexible, able to be molded or shaped by hammering or pressure; adaptable

For malleability in cryptography, see malleability (cryptography). Malleability is a mechanical property of matter, but is most commonly used in reference to metals and metalloids. A malleable metal is capable of being extended, shaped, or otherwise deformed without cracking. This property is important in metalworking, as materials that crack or break under pressure cannot be hammered or rolled. Malleable materials can be formed using stamping or form pressing, whereas brittle metals and plastics must be molded.
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adj. malleable, plastic, pliable, tractable, pliant

(a.)
Capable of being extended or shaped by beating with a hammer, or by the pressure of rollers; -- applied to metals.
  

From the Latin 'malleare', to hammer, the quality of metal that allows it to be easily shaped or formed, by hammering or through pressure.