A Small Spring Hidden in the Arms
Tweezers have no separate spring: the two arms are joined at one end, and that bend acts as the spring. Pressing the arms together changes their shape slightly. The metal resists that change, storing energy as it flexes; release your fingers, and it pushes the arms back toward their original shape.
This is elastic deformation—a reversible bend, like a ruler that springs straight again after a light flex. The metal must be resilient enough to recover, and the arms must not be bent so far that they stay permanently deformed.
Why the Bend Matters
The joined end is both the connection and the source of the restoring force. Its shape and thickness affect how easily the arms close and how firmly they press back. A bend that is too stiff makes the tips tiring to control; one that is too flexible may not grip securely.
That balance turns a single piece of shaped metal into a simple spring mechanism: every squeeze briefly stores energy in the bend, and every release sends it back into the arms.
