The straightening jaw comprises a cubical chuck with a plane face end. The face end has an intake element and an exit element of a straightening groove. Between them is an opening arranged perpendicular to the face end. A straightening insert made of hard metal is inserted into the opening loosely but insured against twisting. On the face end, the straightening insert has a of saddle-shaped straightening indentation that connects the intake and exit elements. Because of this structure, long service lives of the straightening jaw and shorter down times of the straightening device causing low production costs are achieved.
In a device for intermittent straightening of wire there are independent drives for wire feed and the straightening rotor. The speed of rotation (v.sub.2) of the straightening rotor varies essentially synchronously to the feed rate (v.sub.1) of the wire. To cut the wire (t.sub.4) the wire and rotor are stopped. According to the invention the direction of rotation of the rotor is reversed between successive working cycles.
