The Leaded Brasses 



115 



100 



-. 90 



400 500 600 700 800 900 1000 1100 1200 1500 1400 

 Annealing Temp. in Deg.FCl Hr a+Temp.) 



Chart 78. — The effect of annealing on the yield strength of leaded- 

 brass strip, previously cold-rolled 6 B. & S. Nos. (50 per cent reduction 

 of area) from a grain size of 0.035 mm. (60.98 % copper, 1.53 % lead, 

 balance zinc) (0.040-in. stock). 



60 70 80 90 100 110 



Pockwell Hardness F- Vie" Ball 60 Kg. Load 

 5 24 49 58 75 92 



Rockwell Hardness B- Vie" Ball 100 Kg. Load 

 62 68 74 80 85 91 



Rockwell Hardness l5T-'/l6" Ball 15 Kg. Load 

 19 31 44 55 67 78 



Rockwell Hardness JOT" '/le" Ball 30 Kg. Load 



Chabt 79. — This chart can be employed to determine the approxi- 

 mate tensile strength and percentage elongation of leaded-brass strip 

 (60.98 % copper, 1.53 % lead, balance zinc) when only Rockwell hard- 

 ness is known. It is accurate for all thicknesses between 0.020 and 

 0.080 in. within the given limits. 



TABLE 9 

 FREE-CUTTING BRASS ROD 



Copper, 60.99; lead, 3.13%; iron, 0.15%; zinc, balance 



Property 



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



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) 



Elongation, % in 2 in 



Reduction of area, % 



Rockwell hardness F, ^^e-in- ball, 50-kg. load 



Rockwell hardness B, Ke-in- ball, 100-kg. load 



Brinell hardness, 10-mm. ball, 500-kg. load 



Modulus of elasticity, p.s.i 



Melting point, °F 



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 



Density lb. per cu. in 



Type structure 



" Refers to rod cold-worked 30 % ; rod under 1 in. in diameter, ready-to-finish grain size of 0.025 

 ' Refers to a 1300°F. anneal (1 hr.). 



Rod 



