SPECIFICATIONS. 



106. Plates under I2| Ib. per sq. ft.: 



(a) Up to 75 in. wide, 2j per cent above or below. 



(b) Seventy-five inches and up to 100 in. wide, 5 per cent above or 3 per cent below. 



(c) 'One hundred inches wide and over, 10 | r . < nt alxwc or 3 prr rent U-low. 



107. Plates when ordered to gage will be accepted if they measure not more than o.oi in. 

 below the ordered thickness. 



108. An excess over the nominal weight, corresponding to the dimensions on the ord> 



be allowed for each plate, if not more than that shown in the following table, one cu. in. of rolled 

 steel being assumed to weigh 0.2833 ^- : 



109. Cast-iron. Except where chilled iron is specified, castings shall be made of tough gray 

 iron, with sulphur not over o.io per cent. They shall be true to pattern, out of wind and free from 

 flaws and excessive shrinkage. If tests are demanded, they shall be made on the "Arbitration 

 Bar" of the American Society for Testing Materials, which is a round bar ij in. in diameter and 

 15 in. long. The transverse test shall be made on a supported length of 12 in. with load at middle. 

 The minimum breaking load so applied shall be 2,900 ID., with a deflection of at least ^ in. before 

 rupture. 



no. Wrought-Iron. Wrought-iron shall be double-rolled, tough, fibrous and uniform in 

 character. It shall be thoroughly welded in rolling and be free from surface defects. When tested 

 in specimens of the form of Fig. I, or in full-sized pieces of the same length, it shall show an ultimate 

 strength of at least 50,000 Ib. per sq. in., an elongation of at least 18 per cent in 8 in., with fracture 

 wholly fibrous. Specimens shall bend cold, with the fiber, through 135 degrees, without sign of 

 fracture, around a pin the diameter of which is not over twice the thickness of the piece tested. 

 When nicked and bent, the fracture shall show at least 90 per cent fibrous. 



VI. INSPECTION AND TESTING AT THE MILLS. 



111. Mill Orders. The purchaser shall be furnished complete copies of mill orders, and no 

 material shall be rolled nor work done before the purchaser has been notified where the orders have 

 been placed, so that he may arrange for the inspection. 



112. Facilities for Inspection. The manufacturer shall furnish all facilities for inspecting 

 and testing the weight and quality of all material at the mill where it is manufactured. He shall 

 furnish a suitable testing machine for testing the specimens as well as prepare the pieces for the 

 machine, free of cost. 



113. Access to Mills. When an inspector is furnished by the purchaser to inspect material 

 at the mills, he shall have full access, at all times, to all parts of mills where material to be inspected 

 by him is being manufactured. 



VII. WORKMANSHIP. 



114. General. All parts forming a structure shall be built in accordance with approved 

 drawings. The workmanship and finish shall be equal to the best practice in modern bridge works. 

 Material arriving from the mills shall be protected from the weather and shall have clean surfaces 

 before being worked in the shops. 



115. Straightening. Material shall be thoroughly straightened in the shop, by methods that 

 will not injure it, before being laid off or worked in any way. 



116. Finish. Shearing and chipping shall be neatly and accurately done and all portions of 

 the work exposed to view neatly finished. 



117. Size of Rivets. The size of rivets, called for on the plans, shall be understood to mean 

 the actual size of the cold rivet before heating. 



