STRENGTH OF STEEL. 359 



PERCENTAGE OF CARBON IN CRUCIBLE CAST STEEL. 



Razor steel 



Hard file steel 



Turning-tool steel 



Steel for stocks, dies, &c. 

 Graving-tool steel 



...contains 1 '500 per cent, of carbon. 

 ,, 1*375 ,, ,, 



1-250 

 1-125 

 1-000 



Wood-working chisel steel 

 Spring steel 



0-875 



0-500 to 0-550 per cent, 

 of carbon (for railway 

 vehicle springs). 



Mr. Skelton also gives the following as the strength 

 properties of mild structural steel : 



COMPOSITION AND STRENGTH OF STRUCTURAL STEEL. 



The figures marked A and B are from strips cut from 

 plates. In the case of C it will be seen that the lower 

 percentage of carbon is accompanied by a falling off in 

 tensile strength ; these figures relate to strips from 

 plates | in. thick. D is an extra soft steel for locomotive 

 tubes. 



1 86. Tensile Strength of Structural Steel (Campbell). 



The figures in the following table will give a very good 

 idea of the chief properties of structural steel in tension. 

 The figures are taken from Mr. Campbell's book on 

 " Structural Steel " : 



