20 BULLETIN 321, IT. S. DEPARTMENT OF AGRICULTURE. 



The chemical and physical properties of the wire and also the 

 amount of galvanizing carried by it are factors in determining its 

 durability. It is not the purpose of this publication to go into the 

 details of the manufacture of the steel, as these are very exhaustively 

 treated in Farmers' Bulletin No. 239 of the United States Depart- 

 ment of Agriculture. It may be well, however, to mention the proc- 

 esses commonly used in the manufacture of steel wire. The steel 

 from which most of the wire fencing is made at the present time is 

 manufactured by two processes, the Bessemer and the basic open 

 hearth. Formerly steel for wire was made by what was called the 

 puddled-iron process. This process involved the working of the 

 steel by hand labor, which was necessarily slow and expensive, and 

 upon the introduction of the Bessemer and open-hearth processes 

 it was abandoned, as steel could be made by these processes so 

 much more cheaply. It is generally believed that the steel made from 

 the puddled-iron process was superior to that made by the Bessemer 

 and open-hearth processes for the manufacture of wire fencing. 

 Farmers point to the fact that the first woven- wire fences gave them 

 better service than those of the present day. It is, however, im- 

 practicable to make wire from steel manufactured by the puddled- 

 iron process, and the manufacturer of wire fencing of the present 

 day improves his product by increasing the quality and quantity of 

 galvanizing. People have come to realize that the amount of gal- 

 vanizing carried by the wire greatly affects its life and demand 

 fencing with a heavy coating of it. The relative amount of galvan- 

 izing or spelter on a wire may be determined by testing the wire in 

 a solution of copper sulphate. 



TEST FOR WIRE FENCING. 



The common test applied to determine the relative amount of 

 spelter carried by a woven-wire fabric is as follows: A saturated 

 solution of copper sulphate is made by dissolving 36 parts of copper 

 sulphate to 100 parts of water by weight. Not less than a quart of 

 the solution should be used in the test, and to make a quart of the 

 saturated solution requires approximately 11| ounces of copper 

 sulphate, or, as it is commonly called, blue vitriol. Slightly more 

 than this amount should be used, however, as there should be a 

 small excess of the copper sulphate. This may be either left in the 

 solution or the solution may be strained off from it. The wire to be 

 tested is immersed in the prepared solution, which should be at a 

 temperature of 60 to 70° F., and left for one minute, at the end of 

 which time it should be removed and wiped thoroughly dry. This 

 operation should be repeated until the wire shows a deposit of 

 metallic copper. The copper will not be deposited on the wire until 

 the galvanizing is removed and a well-galvanized wire should stand 

 at least three immersions in the copper sulphate solution without 

 showing copper deposits on it. Some specially galvanized wire will 

 withstand four immersions without showing copper. This wire is 



