The present invention relates to a torsion spring comprising a helical spring wire wound around a central axis (A).

The invention relates to a locking element (9) made of spring wire.

The invention relates to a compression spring (1) which is used to control a dynamically stressed element and which is made of a spring wire (2) wound in order to form a cylindrical screw.

At the shot-peeing steps (S6, S7), a compression residual stress is imparted to the spring wire (20).

The surface (3) of the spring wire (2) is modified in order to be resistant to wear and/or to limit friction.

Also provided are a contact probe using said spring wire and a probe unit using said contact probe.

The spring wire (29) is wound in a spiral shape such that the windings (34) thereof do not overlap in the radial direction relative to the spring axis (30).

A spring wire (20) is subjected to a first shot-peening step (S6) and a second shot-peening step (S7).

The high kinetic energy of the first shot produces a compression residual stress from the surface to a deep location of the spring wire (20).

At the first shot-peening step (S6), a first shot is projected at the spring wire (20) at a first projecting speed.

The low kinetic energy of the second shot increases the compression residual stress of a region near the surface of the spring wire (20).

The contact spring mechanism comprises a push-pull spring leaf (4), a movable conductive spring leaf (5,5'),a hot wire conductive spring leaf (7) and a zero wire conductive spring leaf (6).

The hot wire socket spring leaf is connected with the other group of contact spring mechanism for constituting the contact spring mechanism of a hot wire.

The coil-spring winder (212) receives wire (213) from a spool of wire (211) and forms that wire (213) into a coil spring (214).

According to the present invention, when a spring wire rod for forming a spring member of a cushion spring is bent, the tip side of the spring wire rod is prevented from being twisted around to the right and left.