132 



Popular Science Monthly 



wards. When this is done the die is removed 

 and the core drilled out. A flat chisel as 

 shown set E is necessary to break the web 

 left from the drilling of the core. Do 

 not drill the holes too close to the die 

 line, for a cut over the outline will make 

 it necessary to use a put- 

 ting-on tool. It is easier 

 to remove the stock by 

 filing than to hammer the 

 steel to fill the space. 



The die being small it is 

 not necessary to use a 

 milling machine for finish- 

 ing. The finishing is done 

 by chiseling off most of the 

 web and then filing to the 

 lines. When this point is 

 reached and the proper 

 clearance is made, the die 

 is again placed in thq 

 shaper and a cut taken on 

 both sides of the die as at 

 F. This is to make the 

 clamp hold and to prevent 

 the die from lifting out of 

 the bolster. In case of 

 mishaps necessitating 

 regrinding, the die should 

 be cut away as at G, 

 which saves time. A 



The finished die and 

 ready for the power 



in. IS 



depth of j 

 sufficient. Four holes are now drilled and 

 tapped as shown for M-in. screws having 24 

 threads to the inch. Two holes are also 

 drilled for dowel pins. 



Do not forget that there must be a stop 

 for the material after it is blanked. For 

 this purpose a hole is drilled at H and a pin 

 driven in and bent over. 



Die makers are not always permitted to do 

 their own hardening, but should this be a 



fifj 4 tND VltW OF PUNCH 



Plan of the punch 'and manner of cutting 

 the metal away to make the proper shape 



part of your work proceed as follows: Fill 

 up the drilled holes with fire clay to prevent 

 any possible stresses or cracking. After 

 ascertaining what kind of steel you have, 

 and the treatment required, heat it to 



the proper temperature, or color, and 

 queno.h it quickly in water or oil. After 

 hardening the surface of the die, clean it and 

 replace it in the furnace to bring it to a dark 

 straw color, or 460 deg. F. The die is now 

 ready for use in making the punch, which is 

 shaped from a round piece 

 of steel 1 3-2 in. in diameter. 

 A piece of the steel is cut to 

 the right length; the ends 

 are centered, put in a lathe 

 and turned down, as shown 

 in Fig. 4, to the size neces- 

 sary to fit the punch holder 

 for the press work. When 

 this is done, brighten the 

 large end and apply the 

 blue stone solution; clamp 

 the end in a vise and lay 

 the die upon it. Transfer 

 the outline of the die with 

 the scriber. 



Next, take the piece 

 to the milling machine 

 and clamp it in the 

 chuck of the index head or 

 between centers. Mill all 

 around and up close to the 

 line scribed, as shown in 

 the end view. Then re- 

 move it from the chuck 

 and file it so that the punch 

 will just about enter the die; now adjust it 

 in the press as if for use with the already 

 made and hardened die, and "shear it." 

 Care must be taken to see that the die will 

 remove some metal from all sides. When 

 located properly, force the punch into the die. 

 If too much material has been left on the 

 punch, do not attempt to force it through, 

 but remove again and file to mark obtained 

 by this operation. To insure a good, 

 smooth finish as little material as possible 

 should be left to shear. 



The punch is hardened in the same manner 

 as the die and the cutting edge is ground 

 sharp. To complete the job we must now 

 make the stripper plate. A piece of machine 

 steel of about } ^ in. thickness, as shown in Fig. 

 5, is clamped on the die and holes are drilled to 

 coincide with the hole of the die. After the 

 plate is secured to the die the outline of the 

 blank is scribed on the stripper plate in the 

 same manner as on the punch. The core on 

 this plate is drilled out in the same way as for 

 the die. It is filed close to the lines; and punch 

 and die are set on the press again. When 



punch 

 press 



