360 STKKXii'l II OF STKKL. 



TENSILE STRENGTH OF STRUCTURAL STEEL. 



Mr. Campbell also gives the following percentages of 

 carbon which are usual for the chief kinds of steel : 



Kind of Steel. 



Tool steel 



Spring steel 



Rail steel 



Boiler-plate steel 

 Bridge steel 

 Very mild steel . 



Percentage of Carbon. 



0-75 to 1-50 

 About 0-50 

 0-40 to 0-45 

 0-25 to 0-30 

 0-20 

 0-10 to 0-15 



187. Strength of Open-hearth Steel for Boilers. In 



his paper on the above subject, Mr. Hamilton Goodall f 



f Min. Proc. Inst. C.E., vol. xcii. 



