54 



Copper and Copper-base Alloys 



TABLE 5 

 SPRING BRASS 



General Data — Strip" 

 Copper, 74.69%; lead, trace; iron, trace; zinc, balance 



Property 



Tensile strength, p.s.i. (000 omitted) 



Elongation, % in 2 in 



Apparent elastic limit, p.s.i. (000 omitted) 



Yield strength, 0.5% extension, p.s.i. (000 omitted) 



Yield strength, 0.2% offset, p.s.i. (000 omitted) 



Yield strength, 0.1 % offset, p.s.i. (000 omitted) 



Endurance hmit, p.s.i. (000 omitted) 



Rockwell hardness F, iis-m. ball, 60-kg. load 



Rock-nell hardness B, He-™- ball, 100-kg. load 



Rockwell hardness G, Vfe-in. ball, 150-kg. load 



Rockwell hardness 15-T, }i6-m. ball, 15-kg. load 



RockweO hardness 30-T, 3i6-in- ball, 30-kg. load 



Young's modulus of elasticity, p.s.i 



Melting point, °F 



Density, lb. per cu. in 



Coefficient of expansion, per °C. from 25-300°C 



Electrical conductivity, % l.A.C.S. at 20°C, 68°F 



Thermal conductivity, B.t.u. per sq. ft. per ft. per hr. per °F., 68°F 



« All tests conducted on 0.040-in. stock. 



»6 B. & S. Nos., hard, 0.095-0.015 mm. grain size at ready-to-finish, respectively. 



•= 1300°F. anneal for 1 hr. 



Hard'' 



Soff= 



no 



100 



90 



P 80 



^ 70 



^ 60 



-■ 50 

 o 

 o 

 ° 40 



30 



20 



U.O 20.7 29.4 37.2 44.0 50.0 55.5 60.5 64.8 68.6 

 Percen+ Reduction of Area by Rolling 

 01 Z3456789 10 

 B5fS Numbers Hard 



Chabt 78. — The eflfeet of cold rolling on the tensile strength and 

 apparent elastic limit of spring-brass strip, previously annealed to 

 two different grain sizes, 0.015 and 0.095 mm. (74.69 % copper) (0.040- 

 in. stock). 



,,.„ 20.7 29.4 372 44.0 50.0 55.5 60.5 64.8 68.6 

 Percent Reduction ot Area by Rolling 

 01 23456789 10 

 B?;-S Numbers Hard 

 Chart 79. — The effect of cold rolling on the Rockwell hardness and 

 percentage elongation in 2 in. of spring-brass strip, previously annealed 

 to two different grain sizes, 0.015 and 0.095 mm. (74.69 % copper) 

 (0.040-in. stock). 



