292 



Copper and Copper-base Alloys 



TABLE 1 

 MECHANICAL PROPERTIES OF BERYLLIUM COPPER 



General Data — Strip'^^^'*'''' 

 Copper, 97.75%; Beryllium, 2.25% 



Condition 



Johnson's 



elastic 



limit, p.s.i. 



(000 



omitted) 



Tensile 

 strength, 

 p.s.i. (000 

 omitted) 



Elonga- 

 tion, % 

 in 2 in. 



Young's 



modulus, 



p.s.i. X 10- 



Conduc- 



tivity, % 

 I.A.C.S. 



Soft — annealed state 



Soft — then heat-treated at 575 °F., IJ^ hr., salt bath 



Soft — then rolled 2 B. & S. Nos., hard 



Soft — rolled 2 B. & S. Nos., then heat-treated at 550°F., 1 hr., salt bath . 



Soft — rolled 2 B. & S. Nos., then heat-treated at 700°F., 1 hr., salt 



bath 



22 

 100 



55 

 110 



70 

 160 



90 

 180 



50.0 

 8.0 



15.0 

 4.0 



7.0 



17.2 

 22.0 

 17.3 

 23.0 



34.5 



Physical Properties of Beryllium Copper 



Density 



Specific gravity 



Melting range: 



Liquidus 



Solidus 



Coefficient of expansion: 



20-100°C 



20-200°C 



2a-300°C 



0.297 

 8.22 



1751°F. 

 1587°F. 



16.5-16.7 X 10-6 

 16.6-17.1 X 10-6 

 17.5-18.0 X 10-5 



Electrical Conductivity at 20°C. 



Condition 



Beryllium copper, % 



Beryllium copper 

 -f 0.40% nickel, % 



Soft or hard-drawn 



Heat-treated to maximum hardness. . . . 

 Heat-treated to maximum conductivity 



+ 17.5 I.A.C.S. 

 20-25% I.A.C.S. 

 32-38% I.A.C.S. 



17.2 

 18.0 

 20.25 



Thermal Conductivity 



12 3 4 



Beryllium in Percent by Weight 



Fig. 1. — Constitutional diagram of Beryllium-copper alloys according to Masing and Dahl. 



