158 



Copper and Copper-base Alloys 



TABLE 7 

 HARD NAVAL BRASS 



General Data — Steip" 

 Copper, 61.50%; tin, 0.75%; lead, 0.20%; iron, trace; zinc, balance 



Property 



Soft' 



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) 



Y'ield strength, 0.1 % offset, p.s.i. (000 omitted) 



Rockwell hardness F, J-f g-in. ball, 60-kg. load 



Rockwell hardness B, ^iQ-ia. ball, lOO-kg.-load 



Rockweh hardness G, Jfe-i'i- ball, 150-kg. load 



Rockwell hardness 15-T, fj'e-in. ball, 15-kg. load 



Rockwell hardness 30-T, He-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,'"' % I.A.C.S., 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, 0.080-0.015 mm. grain size at ready-to-finish. 



' 1300''F. anneal (1 hr. at temperature) of material described in footnote &. 



110 

 100 



90 



80 



£ 70 

 & 

 •^ 60 



(U 



5-50 



40 



30 



20 



il.O 20.7 294 372 44.0 50.O 55.5 60.5 648 68.6 

 Percent Reducfion of Area by Rolling 

 123456 789 10 

 OS'S Numbers Hard 



CH.iRT 76. — The effect of cold rolling on the tensile strength and 

 apparent elastic limit of hard-naval-brass strip, previously annealed 

 to two different grain sizes, 0.015 and O.OSO mm. (61.50 % copper, 

 0.75 % tin, balance zinc) (0.040-in. stock). 



^110 

 o 

 2 100 



CO 



1 90 

 o 



d^ 80 



S 70 



= 60 

 m 



1^ 50 

 l 40 

 i 30 



D 



X 



= 20 



11.0 20.7 29.4 372 44.0 50.0 55.5 60.5 64.8 68.6 

 Percent Reduction of Area by Rolling 

 01 23456789 10 

 BS^S Numbers Hard 



Chart 77. — The effect of cold rolling on the Rockwell hardness and 

 percentage elongation in 2 in. of hard-naval-brass strip, previously 

 annealed to two different grain sizes, 0.015 and 0.080 mm. (61.50% 

 copper, 0.75 % tin, balance zinc) (0.040-in. stock). ' 



