E.\Gi\r.i:Kixc /7..i.v.\7.\t; /"oa- M.ixir.icirRr. 55.1 



Our most intricate cnnineoriiiK pnihk-ms arisi- in connirtion with 

 punch prt-ss t(H)ls as tht-rc is almost no hmit to the \arii-t\- of opera- 

 tions that can ho performed on this t\iK' of niariiine. 



If the demand for a part tnade on a punch press is small, it is often 

 found more economical to l)uild simple tools which will hl.mk out, 

 perforate and form in separate operations, rather than to build more 

 elahorate tcxils at a higher cost wliicli will comliint' two or more 

 operations into one. 



The effect of ciuantit\- on the desijjii of tools ma\' best be shown b\- 

 a concrete case. 



Fig. 5 



Take, for illustraticin, the case of a simple brass washer 5/8" in 

 diameter, l/lG" thick and having a l/4" hole. As shown in Fig. 5, 

 with a requirement of 5,000 a year, the washer would be made from 

 rod stock in a hand screw machine using general use tools at a cost 

 of SlO.OO a thousand; for 30,000 a \ear it would be made from sheet 

 stock in a punch press using a one-at-a-time tool, at a cost of S2.30 a 

 thousand; for .500,000 a year a three-at-a-time tool would be used 

 at a cost of SI. 72 a thousand; for 3,000,000 a year a seven-at-a-time 

 tool would l)e used at a cost of SI. 52 a thousand. 



In each one of these steps, as shown in the columns at the right, 

 the additional tool investment, necessitated by the more advanced 



