320 



Copper and Copper-base Alloys 



TABLE 20 

 BERYLLIUM COPPER 



o Proportional limit 31,000 p.s.i.; 0.10% proof stress 68,500 p.s.i.; Young's modulus of elasticity 16.3 X 10^ p.s 

 for 6.3 X 10' cycles; elongation measured on 4 v^area. 



* Fatigue specimen taken parallel to direction of rolling; modulus of elasticity 19.1 X 10^ p.s.i. 



*= Fatigue specimen taken parallel to direction of rolling; modulus of elasticity 18.5 X 10^ p.s.i.; proportional limit 48,000 p.s.i. 

 <* Fatigue specimen taken parallel to direction of rolling; proportional limit 55,000 p.s.i.; modulus of elasticity 18.4 X 10^ p.s.i. 

 « Fatigue specimen taken parallel to direction of rolling; proportional limit 39,000 ps..i.; modulus of elasticity 17.2 X 10^ p.s.i. 

 ^ Fatigue specimen taken parallel to direction of rolling; proportional limit 25,900 p.s.i.; modulus of elasticity 19.4 X 10^ p.s.i. 

 Fatigue specimens taken parallel to direction of rolling; proportional limit 49,500 p.s.i.; modulus of elasticity 19.8 X 10^ p.s.i. 



* Tension specimens 0.313 in. in diameter, fatigue specimens 0.300 in. in minimum diameter; machined from 0.500-in.-diameter rod. 



,- fatigue limit, salt spray, 40,000 p.s 



' 0.50% extension yield strength 93,500 p.s.i.; modulus of elasticity 18.8 X 10^ p.s.i. 



