SPECIFICATIONS. 63 



1 20. Allowable Variations. If the ultimate strength varies more than 4,000 Ib. from that 

 <lrMinl, a rrtrst shall be made on the same gage, which, to be acceptable, shall be within 5,000 

 Ib. of thr (Irsircd ultimate. 



121. Chemical Analyses. Chemical determinations of the percentages of carbon, phos- 

 phorus, sulphur and manganese shall be made by the manufacturer from a test ingot taken at 

 thr time of the pouring of each melt of steel and a correct copy of such analysis shall be furnished 

 to the t ni;iiH t r or his inspector. Check analyses shall be made from finished material, if called 

 for by the purchaser, in which case an excess of 25 per cent above the required limits will be 

 allowed. 



122. Form of Specimens. PLATES, SHAPES AND BARS. Specimens for tensile and bending 

 tests for plates, shapes and bars shall be made by cutting coupons from the finished product, 

 which shall have both faces rolled and both edges milled to the form shown by Fig. I ; or with 

 both edges parallel; or they may be turned to a diameter of J in. for a length of at least 9 in., 

 with enlarged ends. 



123. RIVETS. Rivet rods shall be tested as rolled. 



124. PINS AND ROLLERS. Specimens shall be cut from the finished rolled or forged bar, in 

 such manner that the center of the specimen shall be I in. 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 i in. by J in. in section. 



i*"- ! Not less than o" ! 

 I i-y i y iu ! 



-About 18"- 

 FlG. I. 



Abjom a" 



FIG. 2. 



125. 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. 



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

 imens shall be of the form prescribed for pins and rollers. 



126. Annealed Specimens. Material which is to be used without annealing or further 

 treatment shall be tested in the condition in which it comes from the rolls. When material is to 

 be annealed or otherwise treated before use, the specimens for tensile tests representing such 

 material shall be cut from properly annealed or similarly treated short lengths of the full section 

 of the bar. 



127. 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. 



128. Modifications in Elongation. For material less than fV m - a d more than | in. in 

 thickness the following modifications will be allowed in the requirements for elongation: 



(a) For each tV in. in thickness below & in., a deduction of 2\ per cent will be allowed from 

 the specified elongation. 



(6) For each \ in. in thickness above } in., a deduction of i per cent will be allowed from 

 the specified elongation. 



(c) For pins and rollers over 3 in. in diameter the elongation in 8 in. may be 5 per cent less 

 than that specified in paragraph 1 19. 



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

 and bars less than i in. thick shall bend as called for in paragraph 1 19. 



