THE USE OF IRON. J$ 



appears a table compiled from a number of tests of groups of 

 specimens from both acid and basic manufacture, and from 

 this table, two groups of .109 % carbon steel show the other 

 elements as follows: 



(1) Silicon .008 ; Manganese, .310: Sulphur, .036 ; Phosphorus, .066 



(2) " .007; " .380; " .048; .082 

 Ultimate strength of specimen No.' i (acid) 57, 310 Ibs. 



No. 2 (basic) 57,43 " 



According to table showing graduations of steels in relation 

 to their percentages of carbon, it will be seen that this steel 

 will grade as "soft"; ultimate strength, 56,500; elastic 

 limit, 34,000 Ibs. ; stretch in 8 in., 30$; reduction of fractured 

 area, 56 %. 



It is impossible at this time to reconcile all conclusions, 

 and theoretical and scientific considerations must be moulded 

 more or less to fit commercial standards, which have been 

 largely set by the Association of American Steel Manufac- 

 turers, whose standard specifications are the result of much 

 careful consideration and study. 



Deviations from these regulation specifications will be 

 found to entail additional expense to the consumer, possibly 

 not warranted by assumed theoretical conditions, and therefore, 

 in the matter of physical test of steel required, the wording of 

 the specifications " to conform to the standard specifications 

 of the Association of American Steel Manufacturers," would 

 undoubtedly cover the general physical requirements for a 

 serviceable steel which should be " soft," 52,000 to 62,000 Ibs. 

 tensile strength per square inch. 



In the matter of the chemical specifications, this properly 

 comes within the province of the engineer, and the following 

 is suggested: 



CHEMICAL SPECIFICATIONS. 



The plate metal to be used in stand-pipe construction 

 shall be the product of some well-established and reputable 



