214 



STEEL RAILWAY BRIDGES. 



CHAP. IV. 



92. Pin and roller specimens shall be cut from the finished rolled or forged bar, in such manner 

 that the center of the specimen shall be one inch from the surface of the bar. The specimen for 

 tensile test shall be turned to the form shown by Fig. 2. The specimen for bending test shall be 

 one inch by 3-in. in section. 



93. For steel castings the number of tests will depend on the character and importance of 

 the castings. Specimens shall be cut cold from coupons molded and cast on some portion of one 

 or more castings from each melt or from the sink heads, if the heads are of sufficient size. The 

 coupon or sink head, so used, shall be annealed with the casting before it is cut off. Test specimens 

 to be of the form prescribed for pins and rollers. 





- 



? i Not less ilrin 9" ( ! 



| r t t * f 



f 



Abput *'' 

 it 



About' 18" * 



FIG. i 



FIG. 2. 



94. Specimens of Rolled Steel. Rolled steel shall be tested in the condition in which it 

 comes from the rolls. 



95. Number of Tests. At least one tensile and one bending test shall be made from each 

 melt of steel as rolled. In case steel differing f-in. and more in thickness is rolled from one melt, 

 a test shall be made from the thickest and thinnest material rolled. 



96. Modification in Elongation. A deduction of i per cent will be allowed from the specified 

 percentage for elongation, for each f-in. in thickness above f-in. 



97. Bending Tests. Bending tests may be made by pressure or by blows. Plates, shapes 

 and bars less than one inch thick shall bend as called for in paragraph 86. 



98. Thick Material. Full-sized material for eye-bars and other steel one inch thick and 

 over, tested as rolled, shall bend cold 180 degrees around a pin, the diameter of which is equal to 

 twice the thickness of the bar, without fracture on the outside of bend. 



99. Bending Angles. Angles f-in. and less in thickness shall open flat, and angles |-in. and 

 less in thickness shall bend shut, cold, under bl Jws of a hammer, without sign of fracture. This 

 test shall be made only when required by the inspector. 



100. Nicked Bends. Rivet steel, when nicked and bent around a bar of the same diameter 

 as the rivet rod, shall give a gradual break and a fine silky uniform fracture. 



101. Finish. Finished material shall be free from injurious seams, flaws, cracks, defective 

 edges or other defects, and have a smooth, uniform and workmanlike finish. Plates 36 in. in 

 width and under shall have rolled edges. 



102. Melt Numbers. Every finished piece of steel shall have the melt number and the 

 name of the manufacturer stamped or rolled upon it. Steel for pins and rollers shall be stamped 

 on the end. Rivet and lattice steel and other small parts may be bundled with the above marks 

 on an attached metal tag. 



103. Defective Material. Material which, subsequent to the above tests at the mills, and 

 its acceptance there, develops weak spots, brittleness, cracks or other imperfections, or is found 

 to have injurious defects, will be rejected at the shop and shall be replaced by the manufacturer at 

 his own cost. 



104. Variation in Weight. A variation in cross-section or weight of each piece of steel of 

 more than 2| per cent from that specified will be sufficient cause for rejection, except in case of 

 sheared plates, which will be covered by the following permissible variations, which are to apply 

 to single plates, when ordered to weight: 



105. Plates \2\ Ib. per sq. ft. or heavier: 



(a) Up to 100 in. wide, 2\ per cent above or below the prescribed weight. 



(b) One hundred inches wide and over, 5 per cent above or below. 



