SPECIFICATIONS FOR WROUGHT-IRON PLATES. 



4. Modifications in Elongation. For plates under ^ in. in thickness, a deduction of i from 

 tin- prtvfiu. r.;r-; ul i-lon^.uioa specified in Section 3 shall be made for each decrease of -fa in. in 

 thickness In-low iV in. 



5. Bend Tests, (a) Cold-bend Tests. The test specimen shall bend cold through 90 deg. 

 without fracture on the outside of the bent portion, as follows: For Class A plates, around a pin 

 tin- ili.inu-ti-r of which is i-qual to ij times the thickness of the specimen; and for Class B plates, 

 around a pin the diameter of which is equal to 3 times the thickness of the specimen. 



(b) Nick-bend Tests. The test specimen, when nicked on one side and broken, shall show , 

 for ( 'lass A plates a wholly fibrous fracture, and for Class B plates, not more than 10 per cent of 

 tlu- fractured surface to be crystalline. 



6. Test Specimens. Tension and bend test specimens shall be taken from the finished plates 

 and shall be of the full thickness of plates as rolled. The longitudinal axis of the specimen shall 

 be parallel to the direction in which the plates are rolled. 



7. Number of Tests, (a) One tension, one cold-bend and one nick-bend test shall be made 

 for each variation in thickness of J in. and not less than one test for every ten plates as rolled. 



(b) If any test specimen fails to conform to the requirements specified through an apparent 

 local defect, -a retest shall be taken; and should the retest fail, the plates represented by such test 

 shall be rejected. 



III. FINISH. 



8. Finish. The plates shall be straight, smooth and free from cinder spots and holes, and 

 free from injurious flaws, buckles, blisters, scams and laminations. 



IV. INSPECTION AND REJECTION. 



9. Inspection, (a) 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 manu- 

 facturer's works which concern the manufacture of the plates ordered The manufacturer shall 

 afford the inspector, free of cost, all reasonable facilities to satisfy him that the plates are being 

 furnished in accordance with these specifications. Tests and inspection at the place of manu- 

 facture shall be made prior to shipment. 



(ft) The purchaser may make the tests to govern the acceptance or rejection of plates at his 

 own laboratory or elsewhere. Such tests, however, shall be made at the expense of the purchaser. 



STEEL. The three principal methods for the manufacture of steel are (i) the crucible 

 process, (2) the Bessemer process, and (3) the open-hearth process. The crucible process is used 

 for making tool steel. The Bessemer process is used for making structural steel, but on account 

 of its requiring a high grade ore for a satisfactory steel, and the difficulty of control, it is now 

 practically replaced by the open-hearth process. The following description of the methods of 

 manufacture of steel is taken from Kent's " Mechanical Engineer's Pocket-Book," page 451, 8th 

 Edition, 1910. 



The Manufacture of Steel. Cast steel is a malleable alloy of iron, cast from a fluid mass. 

 It is distinguished from cast iron, which is not malleable, by being much lower in carbon, and from 

 wrought iron, which is welded from a pasty mass, by being free from intermingled slag. Blister 

 steel is a highly carbonized wrought iron, made by the " cementation " process, which consists 

 in keeping wrought-iron bars at a red heat for some days in contact with charcoal. Not over 2 

 per cent of C is usually absorbed. The surface of the iron is covered with small blisters, supposedly 

 due to the action of carbon on slag. Other wrought steels were formerly made by direct processes 

 from iron ore, and by the puddling process from wrought iron, but these steels are now replaced 

 by cast steels. Blister steel is, however, still used as a raw material in the manufacture of crucible 

 steel. Case-hardening is a process of surface cementation. 



