In a ductile manner; with the quality of being able to be drawn out or shaped without breaking.
From 'ductile' plus the adverb suffix '-ly'. This adverb form is rare in practice, as ductility is usually described as a noun property rather than an adverbial quality.
Ductilely is technically correct English but almost never used—it's an example of how not all grammatically possible word forms are actually practical, and languages evolve to avoid cumbersome adverbs.
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