506 ENGINEERING MATERIALS. CHAP. XV. 



Tensile strength, Ib. per sq. in 45,000-55,000 



Yield point, min., Ib. per sq. in 0.5 tens. str. 



_, . . . 1,500,000 



Elongation in 8 in., mm., per cent , =* 



Tens. str. 



(But need not exceed 30 per cent) 



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



6. Bend Tests, (a) Cold-bend Tests. The test specimen shall bend cold through 180 deg. 

 flat on itself without cracking on the outside of the bent portion. 



(b) Quench-bend Tests. The test specimen, when heated to a light cherry red as seen in the 

 dark (not less than 1200 F.), and quenched at once in water the temperature of which is between 

 80 and 90 F., shall bend through 180 flat on itself without cracking on the outside of the bent 

 portion. 



7. Test Specimens. Tension and bend test specimens shall be of the full-size section of 

 material as rolled. 



8. Number of Tests, (a) Two tension, two cold-bend, and two quench-bend tests shall be 

 made from each melt, each of which shall conform to the requirements specified. 



(b) If any test specimen develops flaws, or if a tension test specimen breaks outside the middle 

 third of the gage length, it may be discarded and another specimen substituted. 



IV. PERMISSIBLE VARIATIONS IN GAGE. 



9. Permissible Variations. The gage of each bar shall not vary more than o.oi in. from that 

 specified. 



V. WORKMANSHIP AND FINISH. 



10. Workmanship. The finished bars shall be circular within o.oi in. 



11. Finish. The finished bars shall be free from injurious defects, and shall have a workman- 

 like finish. 



VI. MARKING. 



12. Marking. Rivet bars shall, when loaded for shipment, be properly separated and marked 

 with the name or brand of the manufacturer and the melt number for identification. The melt 

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



VII. INSPECTION AND REJECTION. 



13. Inspection. The inspector representing the purchaser shall have free entry, at all times 

 while work on the contract of the purchaser is being performed, to all parts of the manufacturer's 

 works which concern the manufacture of the bars ordered. The manufacturer shall afford the 

 inspector, free of cost, all reasonable facilities to satisfy him that the bars are being furnished in 

 accordance with these specifications. All tests (except check analyses) and inspection shall be 

 made at the place of manufacture prior to shipment, unless otherwise specified, and shall be so 

 conducted as not to interfere unnecessarily with the operation of the works. 



14. Rejection, (a) Unless otherwise specified, any rejection based on tests made in accord- 

 ance with Section 4 shall be reported within five working days from the receipt of samples. 



(b) Bars which show injurious defects subsequent to their acceptance at the manufacturer'? 

 works will be rejected, and the manufacturer shall be notified. 



15. Rehearing. Samples tested in accordance with Section 4, which represent rejected bars, 

 shall be preserved for two weeks from the date of the test report. In case of dissatisfaction with 

 the results of the tests, the manufacturer may make claim for a rehearing within that time. 



B. Requirements for Rivets. 

 I. PHYSICAL PROPERTIES AND TESTS. 



16. Tension Tests. The rivets, when tested, shall conform to the requirements as to tensile 

 properties specified in Section 5, except that the elongation shall be measured on a gage length not 

 less than four times the diameter of the rivet. 



17. Bend Tests. The rivet shank shall bend cold through 180 degrees flat on itself without 

 cracking on the outside of the bent portion. 



1 8. Flattening Tests. The rivet heads shall flatten, while hot, to a diameter 2 times the 

 diameter of the shank without cracking at the edges. 



19. (a) When specified, one tension test shall be made from each size in each lot of rivets 

 offered for inspection. 



