DEVELOPMENTS IN MANUFACTURE OF COPPER WIRE 209 



conditions adopted for drawing wire to finished sizes without anneaUng 

 during the process. 



20 Use. 



\5 Lbs. 



10 Lbs. 



5 Las 



Lbs.O^ 



22 23 2* 25 26 27 28 29 JO 31 3Z 33 34 35 J6 37 38 39 40 On Sue 

 ' 2 3 4 5 6 7 6 9 10 H IM3 14 15 16 17 16 RtpucTioN 



Fig. 19 



Chilled Iron Dies 

 The dies used for drawing heavy wire are cast with a tapered hole 

 from chilled cast iron and reamed to the desired size. When the die 

 wears too large for a particular size of wire, it is reamed to a larger size 

 and used in that manner until the die goes above the maximum size 

 used. These dies, shown in Fig. 20, are used for drawing line and heavy 

 gauge wire for which the cost of diamond dies would be excessive. 

 Many alloy steel dies have been tested as substitutes for chilled iron 

 dies for copper wire drawing, but so far have failed to replace them, due 



