500 



ENGINEERING MATERIALS. 



CHAP. XV. 



II. CHEMICAL PROPERTIES AND TESTS. 



3. Chemical Composition. The steel shall conform to the following requirements as to 

 chemical composition: 



STRUCTURAL STEEL. RIVET STEEL. 



per cent. 



r>. t, ( Acid ............ not over 0.06 not over 



Phosphorusj Basic ............ 004 



Sulphur .................... . " ' 0.05 0.04 " 



4. Ladle Analyses. An analysis to determine the percentages of carbon, manganese, phos- 

 phorus and sulphur shall be made by the manufacturer from a test ingot taken during the pouring 

 of each melt, a copy of which shall be given to the purchaser or his representative. This analysis 

 shall conform to the requirements specified in Section 3. 



5. Check Analyses. Analyses may be made by the purchaser from finished material repre- 

 senting each melt, in which case an excess of 25 per cent above the requirements specified in 

 Section 3 shall be allowed. 



III. PHYSICAL PROPERTIES AND TESTS. 



6. Tension Tests, (a) The material shall conform to the following requirements as to tensile 

 properties: 



(6) The yield point shall be determined by the drop of the beam of the testing machine. 



7. Modifications in Elongation, (a) For structural steel over f in. in thickness, a deduction 

 of I from the percentage of elongation in 8 in. specified in Section 6 (a), shall be made for each 

 increase of | in. in thickness above f in. 



(b) For structural steel under -fa in. in thickness, a deduction of 2.5 from the percentage of 

 elongation in 8 in. specified in Section 6 (a), shall be. made for each decrease of YS in. in thickness 

 below rs m - 



8. Bend Tests, (a) The test specimen for plates, shapes, and bars shall bend cold through 

 1 80 deg. without cracking on the outside of the bent portion, as follows: For material f in. or under 

 in thickness, flat on itself; for material over f in. to and including i in. in thickness, around a pin 

 the diameter of which is equal to the thickness of the specimen; and for material over if in. in 

 thickness, around a pin the diameter of which is equal to twice the thickness of the specimen. 



(6) The test specimen for pins and rollers shall bend cold through 180 deg. around a i-in. 

 pin without cracking on the outside of the bent portion. 



(c) The test specimen for rivet steel shall bend cold through 180 deg. flat on itself without 

 cracking on the outside of the bent portion. 



9. Tests of Angles. Angles f in. or under in thickness shall open flat, and angles 5 in. or 

 under in thickness shall bend shut, cold, under blows of a hammer without cracking. This test 

 shall be made only when required by the inspector. 



10. 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. They may be machined to the form 

 and dimensions shown in Fig. I, or with both edges parallel; except that bend test specimens for 

 eye-bar flats may have three rolled sides. 



(d) Tension and bend test specimens for plates and bars (except eye-bar flats) over if in. in 

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

 least 9 in. 



1 See section 7. 



