498 



ENGINEERING MATERIALS. 



CHAP. XV. 



8. Test Specimens, (a) Tension and bend test specimens shall be taken from the finished 

 rolled or forged material, and shall not be annealed or otherwise treated, except as specified in 

 Paragraph (&). 



(b) Tension and bend test specimens for material which is to be annealed or otherwise treated 

 before use, shall be cut from properly annealed or similarly treated short lengths of the full section 

 of the piece. 



(c) Tension and bend test specimens for plates, shapes and bars, except as specified in Para- 

 graph (d), shall be of the full thickness of material as rolled; and may be machined to the form and 

 dimensions shown in Fig. i, or with both edges parallel. 



About 18" 

 FlG. I. 



(d) Tension and bend test specimens for plates and bars over r in. in thickness or diameter 

 may be machined to a thickness or diameter of at least j in. for a length of at least 9 in. 



(e) The axis of tension and bend test specimens for pins and rollers shall be I in. from the 

 surface and parallel to the axis of the bar. Tension test specimens shall be of the form and di- 

 mensions shown in Fig. 2. Bend test specimens shall be I by 5 in. in section. 



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

 rolled. 



9. 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. 



(b) 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. 



10. 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 \2\ 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 \2\ 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 

 steel being assumed to weigh 0.2833 Ib.: 



