394 



CAMBEIA STEEL. 



III. PHYSICAL PROPEETIES AND TESTS. 

 Tension Tests. 



6. The steel shall conform to the following requirements as to tensile 

 properties: 



* See section 8. f See section 9. 

 Yield Point. 



7. The yield point shall be determined by the drop of the beam of the 

 testing machine. 



Modification in Tensile Strength. 



8. Class B steel may have tensile strength up to 70,000 Ib. maximum, 

 provided the elongation is not less than the percentage required for 65,000 Ib. 

 tensile strength. 



Modifications in Elongation. 



9. (a) For material over % in. in thickness, a deduction of 1 from the 

 percentage of elongation in 8 in. specified for Classes A and B in section 6 

 shall be made for each increase of H in. in thickness above M in., to a minimum 

 of 18 per cent. 



(b) For material under & in. in thickness, a deduction of 2.5 from the 

 percentage of elongation in 8 in. specified for Classes A and B in section 6 

 shall be made for each decrease of fj in. in thickness below & in. 



Character of Fracture. 



10. All broken tension test specimens shall show a silky fracture. 

 Bend Tests. 



11. (a) The test specimen for plates, shapes and bars shall bend cold 

 through 180 deg. without fracture on the outside of the bent portion, as follows: 

 For material % in. and under in thickness, flat on itself; for material over 

 M in. up to 1M in. in thickness, around a pin the diameter of which is equal 

 to 1% times the thickness of the specimen; and for material over 1M in. in 

 thickness, around a pin the diameter of which is equal to twice the thickness 

 of the specimen. 



