STRENGTH OF WROUGHT IRON. 



349 



181. Elastic Moduli for Wrought Iron. The modulus 

 of elasticity in tension of wrought iron varies from 12,200 

 to 13,500 tons per square inch in most cases ; these 

 values correspond to 27,400,0001bs. and a little over 

 30,000, OOOlbs. per square inch. 



2400 



2000 



1600 



1200 



<800 



400 



3OO 600 9OO 



Twisting moments. Inch pounds. 



12OO 



15OO 



FIG. 171. TORSION, LOAD-STRAIN DIAGRAM FOR WROUGHT IRON. 

 Shaft Sin. long and 0'469in. diam. 



The modulus in compression is, if anything, slightly 

 less than in tension for the same material, the ratio being 

 about 1-03 to I'OO. 



