Among the patented methods of fastening the bars together for beams and girders, is the Unit Girder Frame System. The loose bars are bent and made into a frame as shown in Fig. 183. All this work is done in a shop; and the frames are sent to where the building is being constructed, ready to be placed. The stirrups are made of round or flat bars, and are hot-shrunk on the longitudinal rods. The girder, beam, or column unit is shipped to the site of the building being constructed, bearing a tag numbered to correspond with a number on the plan showing the proper position of the reinforcement.