PURPOSE: To prevent the occurrence of twisting of a round bar due to tension of a wire rod by providing two rolls having grooves for winding a wire rod round a long round bar, thereby simultaneously rotating and feeding the round bar.

CONSTITUTION: Rolls 12a, 12b are inclined to be reversed according to the feed speed of a round bar 1 by an angle adjust device 13, and a reciprocating table 14 is moved until the rolls 12a, 12b circumscribe the round bar 1. Further, a wire rod 2 is pierced through a gap between grooves of the rolls 12a, 12b and the round bar 1 and wound round the round bar several times. Subsequently, when a motor 7 is operated, a connecting roll 12a is rotated to rotate the round bar 1 circumscribing the roll 12a and the roll 12b circumscribing the round bar 1. Simultaneously the rolls 12a, 12b circumscribing the round bar 1 move the round bar 1 axially, so that the wire rod 2 wound round the round bar 1 is spirally wound round the round bar 1 to be taken up thereon. As the round bar is clamped and supported from both sides and the wire rod is wound round the round bar, the round bar is mounted from twisting.