Abstract: In a method of manufacturing a reinforcing unit in the form of a cage or basket for a concrete post, the reinforcing rods are placed on pivotable, concave support arms in a fixture so as to form two separate concave parts of the finished unit. Support rings are then secured along said parts perpendicularly to the axis of the finished unit. The parts are brought together, and the support rings of one part are joined to the reinforcing rods of a corresponding part. The said parts are preferably brought together by swinging the support arms upwards in a manner such that the axis of the cage falls in a vertical longitudinal medium plane through the fixture. The support arms are pivoted downwards, whereupon a helical reinforcing element is threaded onto the unit from one end thereof and joined thereto.In this method use is made of a plurality of fixture units each comprising a frame, and two concave support arms pivotally arranged around horizontal shafts.