SPECIFICATIONS FOR STRUCTURAL STEEL FOR BRIDGES. 



601 



(e) Tin- axi-, <>f IC-IIMUM and Ix-ml test specimens for pins and rollers shall be I in. from the 

 .Ki- .iii.l p.ti.illd in tin- ,i\i- M I the bar. Tension test specimens shall be of the form and di- 

 ii?, shown in Fig. 2. Bend test specimens shall be I by J in. in section. 



<- -- About 18" 



J 



rolle 



Tension and bend test specimens for rivet steel shall be of the full-size section of bars as 



11. Number of Tests, (a) One tension and one bend test shall be made from each melt; 

 except that if material from one melt differs f in. or more in thickness, one tension and one bend 

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



(6) If any test specimen shows defective machining or develops flaws, or if an 8-in. tension 

 test specimen breaks outside the middle third of the gage length, or if a 2-in. tension test specimen 

 breaks outside the gage length, it may be discarded and another specimen substituted. 



IV. PERMISSIBLE VARIATIONS IN WEIGHT AND GAGE. 



12. Permissible Variations. The cross-section or weight of each piece of steel shall not vary 

 more than 2.5 per cent from that specified; except in the case of sheared plates, which shall be 

 covered by the following permissible variations to apply to single plates: 



(a) When Ordered to Weight. For plates 123 Ib. per sq ft. or over: 

 Under 100 in. in width, 2.5 per cent above or below the specified weight; 

 loo in. in width or over, 5 per cent above or below the specified weight. 



For plates under 12^ Ib. per sq. ft.: 



Under 75 in. in width, 2.5 per cent above or below the specified weight; 



75 to 100 in., exclusive, in width, 5 per cent above or 3 per cent below the specified weight; 



100 in. in width or over, 10 per cent above or 3 per cent below the specified weight. 



(b) When Ordered to Gage. The thickness of each plate shall not vary more than o.oi in. 

 under that ordered. 



An excess over the nominal weight corresponding to the dimensions on the order shall be 

 allowed for each plate, if not more than that shown in the following table, one cubic inch of rolled 

 teel being assumed to weigh 0.2833 Ib.: 



13. Finish, 

 inlike finish. 



V. FINISH. 

 The finished material shall be free from injurious defects and shall have a work- 



VI. MARKING. 



14. Marking. The name or brand of the manufacturer and the melt number shall be legibly 

 stamped or rolled on all finished material, except that rivet and lattice bars and other small 

 sections shall, when loaded for shipment, be properly separated and marked for identification. 

 The identification marks shall be legibly stamped on the end of each pin and roller. The melt 

 number shall be legibly marked, by stamping if practicable, on each test specimen. 



