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BELL SYSTEM TECHNICAL JOURNAL 



phosphor-bronze alloys and the Rockwell hardnesses reported here- 

 inafter for these materials are the values obtained using a 150-kg. 

 load, a i^-in. diameter ball and reading on the "B" scale or red 

 figures. The 60-kg. load is used for testing annealed material. (See 

 Table IV.) 



Fatigue Tests: 



The endurance limit of each of the metals covered by this paper has 

 been determined for the annealed condition and as rolled four and ten 

 numbers hard. The results of these tests are covered by another 

 paper.^ 



Bend Test Machine: 



In connection with the Amsler bend test machine, an improvement 

 on this machine has been developed employing a motor drive and 

 accurately prepared and aligned jaws. Figure 4 shows a model of 



Fig. 4 — -Experimental Bend Testing Machine. 



T is the tensioning grip. 

 C is the guide clamp. 



'J. R. Townsend and C. H. Greenall, "Fatigue Studies of Non-Ferrous Sheet 

 Metals," presented before the American Society for Testing Materials in June, 1929 



5 is the specimen. 

 B is the radius block. 



