A process for twisting conducting wires to be applied in an electric machine, comprising the steps of: a) providing an apparatus comprising: - a device, which includes: - an outer casing; - a fork, rotatably supported by the outer casing and comprising a pair of prongs elongated in a direction perpendicular to the rotation axis of the fork, between which prongs one or more conducting wires are insertable along a direction parallel to the rotation axis of the fork, such that the rotation of said fork causes a twisting of the conducting wire; and - a transmission mechanism, housed in the outer casing and adapted to rotate the fork; - a supporting structure, fixed relative to a reference plane; and - a slide, movable with respect to the supporting structure integrally with the device along a direction perpendicular to the rotation axis of the fork, such that said device is movable perpendicular with respect to the wire to be twisted; b) providing a part of an electric machine and relative windings, so that said windings protrude from the slots of the electric machine part and are not permanently in place yet; c) stretching a plurality of conducting wires forming said windings towards a first direction; d) moving the device in such a way that it is arranged transversely with respect to said first direction; e) inserting the plurality of conducting wires into the fork of the device; f) rotating the fork one or more times about an axis parallel to said first direction, so as to twist the one or more conducting wires on themselves; g) cutting the plurality of conducting wires; and h) inserting the plurality of conducting wires in isolating sheaths. a) providing an apparatus comprising: - a device, which includes: - an outer casing; - a fork, rotatably supported by the outer casing and comprising a pair of prongs elongated in a direction perpendicular to the rotation axis of the fork, between which prongs one or more conducting wires are insertable along a direction parallel to the rotation axis of the fork, such that the rotation of said fork causes a twisting of the conducting wire; and - a transmission mechanism, housed in the outer casing and adapted to rotate the fork; - a supporting structure, fixed relative to a reference plane; and - a slide, movable with respect to the supporting structure integrally with the device along a direction perpendicular to the rotation axis of the fork, such that said device is movable perpendicular with respect to the wire to be twisted; - a device, which includes: - an outer casing; - a fork, rotatably supported by the outer casing and comprising a pair of prongs elongated in a direction perpendicular to the rotation axis of the fork, between which prongs one or more conducting wires are insertable along a direction parallel to the rotation axis of the fork, such that the rotation of said fork causes a twisting of the conducting wire; and - a transmission mechanism, housed in the outer casing and adapted to rotate the fork; - an outer casing; - a fork, rotatably supported by the outer casing and comprising a pair of prongs elongated in a direction perpendicular to the rotation axis of the fork, between which prongs one or more conducting wires are insertable along a direction parallel to the rotation axis of the fork, such that the rotation of said fork causes a twisting of the conducting wire; and - a transmission mechanism, housed in the outer casing and adapted to rotate the fork; - a supporting structure, fixed relative to a reference plane; and - a slide, movable with respect to the supporting structure integrally with the device along a direction perpendicular to the rotation axis of the fork, such that said device is movable perpendicular with respect to the wire to be twisted; b) providing a part of an electric machine and relative windings, so that said windings protrude from the slots of the electric machine part and are not permanently in place yet; c) stretching a plurality of conducting wires forming said windings towards a first direction; d) moving the device in such a way that it is arranged transversely with respect to said first direction; e) inserting the plurality of conducting wires into the fork of the device; f) rotating the fork one or more times about an axis parallel to said first direction, so as to twist the one or more conducting wires on themselves; g) cutting the plurality of conducting wires; and h) inserting the plurality of conducting wires in isolating sheaths.