794 



BELL SYSTEM TECHNICAL JOURNAL 



130,000 



120,000 



110.000 



100.000 



90,000 



80.000 



70.000 



60000 



50.000 



/ 



-j^ 



/ 



/ 



^^ 



DASHED LINES 

 SHOW TENSILE 

 LIMITS 



/ 



X' 



/ 



/ 



/ 



/ 



/ 



/ 



^ 



/ 



/ 



/ 



/ 



V 

 / 



/ 



^: 



/ 



/^ 



/ 



/ 



-2 Q 



:^ 



a r^ 



/ 



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x, 



.^ 



/ 



y^ 



0=I4GA 

 X=I6 

 + = 18 

 • =?0 

 e=22 

 ® =24 

 e =26 



n =28 



A=30 

 ffi=32 

 a =34 

 ® =36 



(.064") 

 (.051") 

 (.040") 

 (.032") 

 (.025") 

 (.020") 

 (.016") 

 C0I25") 

 (.010") 

 (.008") 

 (006") 

 (.005") 



-10 



10 20 30 



PERCENT REDUCTION 



40 50 



BY ROLLING 



60 



70 



Fig. 18 — Relation of Tensile Strength to Percentage of Reduction of Alloy C 

 Phosphor-Bronze Rolling Series. 



Experience Data 



During and subsequent to the laboratory work covered in this 

 paper, a series of data was obtained on regular commercial shipments 

 of non-ferrous sheet material. About 700 lots of brass, nickel-silver 

 and phosphor-bronze sheet in various tempers and grades were tested 

 on the Rockwell and scleroscope by both the producer and consumer. 

 The lots ranged in size from 100 to about 50,000 lbs. of sheet metal 

 and included material from at least five different mills. The sheet 

 ranged in thickness from 0.010 to 0.500 in. A representative sample 

 about 6 in. long and from 1 to 6 in. wide was taken from each 

 lot. Tests were made on identical samples, five readings being made 

 with each instrument and the average taken. All tests were made 

 by the inspectors who were normally responsible for the control of the 

 material, even though they were not in all cases familiar with the opera- 

 tion of the Rockwell machine. The Rockwell machines were, of 



