SPECIFICATIONS 



409 



head, but develop 10 per cent elongation and the ultimate 

 strength specified, it shall not be cause for rejection, provided 

 not more than one-third of the total number of bars tested 

 break in the head; otherwise the entire lot will be rejected. 



122. Pins made of either of the above mentioned grades 

 of steel shall, on specimen test pieces cut from finished mate- 

 rial, fill the requirements of the grade of steel from which they 

 are rolled, excepting the elongation, which shall be decreased 

 5 per cent from that specified. 



123. In steel ^ inch or less in thickness punched rivet 

 holes, pitched two diameters from a sheared edge, must stand 

 drifting until the diameter is one-third larger than the original 

 hole, without cracking the metal. 



124. The slabs for rolling plates shall be rolled from 

 ingots of at least twice their cross-section. 



125. Pins up to 7 inches diameter shall be rolled. 



126. A variation in cross-section or weight of rolled 

 material of more than 2^ per cent from that specified, may be 

 cause for rejection, except in the case of plates which will be 

 covered by the manufacturer's standard specifications (Cambria 

 Steel, page 345). 



STEE;IV CASTINGS. 



127. Steel castings shall be made of open hearth steel 

 containing from 0.25 to 040 per cent carbon, and not over 0.08 

 per cent of phosphorus nor 0.05 per cent sulphur, and shall 

 be practically free from blow holes. 



CAST IRON. 



128. Except where chilled iron is specified, all castings 

 shall be of tough, gray iron, free from injurious cold shuts 

 or blow holes, true to pattern, and of workmanlike finish. Test 

 bars one inch square, loaded in middle between supports 12 

 inches apart, shall bear 2,500 pounds or over, and deflect 0.15 

 of an inch before rupture. 



WROUGHT IRON. 



129. All wrought iron must be tough, ductile, fibrous and 

 of uniform quality. Finished bars must be thoroughly welded 



Pin Steel. 



Drifting. 



Slab8 for Plates. 

 Pins. 



Variation in 

 Weight. 



Steel Castings. 



Cast Iron. 



Character and 

 Finish. 



