THE USE OF IRON. 7 1 



would certainly prove a suitable material, whilst the stipula- 

 tions are not so severe as to appear too arbitrary or such that 

 there should be any difficulty upon the part of the manufac- 

 turer in filling the order, hence the market quotation upon 

 such plate should be sufficiently reasonable as to permit of its 

 use for such structures. 



Practically the steel called for by Prof. Pence is a " flange 

 steel," worth, according to the quotations above cited, $1.25 

 per 100 Ibs. f. o. b. at mill. One of the best authorities in the 

 United States writes as follows regarding structural steel for 

 stand-pipe work : 



" In the matter of stand-pipe construction, the quality of 

 the steel depends a good deal on the size of the stand-pipe. 

 That is, on the thickness and size of the plates which you are 

 to use. Also whether you are going to drill and ream the 

 material. Roughly speaking, the specifications should be 

 about as follows:" 



" Soft open-hearth steel; to be either acid or basic; tensile 

 strength, 54,000 to 62,000 Ibs. ; elastic limit not less than 

 33,000; elongation, 26^; reduction of area. 50$; sulphur, 

 if acid open-hearth steel, less than .06^; phosphorus less 

 than .075$. If basic open-hearth steel, phosphorus to be 

 under .035 and sulphur under .035^. Bend tests should be 

 made on strips about ij in. wide, planed parallel, and then 

 should be bent 180 degrees flat upon themselves without show- 

 ing sign of fracture on either the convex or concave side of the 

 curve. This test should be carefully carried out on each plate. 

 Certain drift tests should also be made; that is, a hole 15-16 in. 

 in diameter, or whatever size the rivet-hole is, should be drifted 

 to twice its size without cracking or injuring the plate." 



This authority practically agrees with the conclusions 

 ascribed to Prof. Pence as to the quality of steel suitable for 

 stand-pipe work. As has been shown, the thickness of plate 

 affects the physical properties, and should therefore, it appears 



