STEEL REINFORCEMENT 



261 



in section are shown in Fig. 4. The fins are partly sheared 

 across and also in a direction parallel with the axis of the bar, 

 and are bent up, as shown in Fig. 3 so as to form a grip with 

 the concrete and to provide the stirrups, or web members, 

 necessary to resist diagonal stresses. 



The Kahn bars are made in the several sizes indicated 

 in Fig. 4. The respective sectional areas of the bars are also 



FIG. 4 



given in^this figure. These bars are rolled of mild steel, as 

 this metal will best stand the shearing stresses to which the 

 bar is subjected in manufacture. The elastic limit of the 

 metal in the bars ranges from 33,000 to 35,000 Ib. per sq. in. 

 Trus-Con Bar. Another deformed bar, known as the 

 trus-con bar, is illustrated in Fig. 5. This bar is round in 



