The Coppers 



13 



500 600 700 800 900 1000 1100 1200 1300 1400 

 Annealing Temp, in Deg. F. (1 Hr. at Temp.) 



Chart 30. — The effect of annealing on the Rockwell F and B hard- 

 ness and percentage elongation in 2 in. of oxygen-free copper strip 

 (no residual deoxidant) previously cold-rolled 6 B. & S.' Nos. (50 per 

 cent reduction of area) from material annealed to different grain sizes, 

 0.015 and 0.040 mm. (99.94% copper) (0.040-in. stock). 



500 600 700 800 900 1000 HOC 1200 1300 1400 

 Annealing Temp, in Deg. F! (I Hr. atTemp.) 



Chart 31. — The effect of annealing on the yield strengths of oxygen- 

 free copper strip (no residual deoxidants) previously cold-rolled 6 B. & 

 S. Nos. (50 per cent reduction of area) from a material having a grain 

 size of 0.015 mm. (99.94 % copper) (0.040-in. stock). 



500 600 700 800 900 1000 1100 1200 1300 1400 

 Annealing Temp.in Deg.H (1 Hr:a+ Temp.) 



Chart 32. — The effect of anneaUng on the yield strengths of oxygen- 

 free copper strip (no residual deoxidants) previously cold-rolled 

 6 B. & S. Nos. (50 per cent reduction of area) from a material having a 

 grain size of 0.040 mm. (99.94 % copper) (0.040-in. stock). 



70 



60 



•^50 



40 



30 



20 



O 0) 



en.— 



30 40 50 60 70 80 90 100 

 Rockwell Hardness F-I^IS" Ball 60 Kg. Load 



5 23 40 58 76 



Rockwell Hardness B-'/ie" Ball 100 Kg. Load 



63 68 74 80 85 



Rockwell Hardness l5-T-'/i6" Ball 15 Kg. Load 



19 31 43 55 67 



Rockwell Hardness 30-T-'/i6" Boll 30 Kg. Load 



Chart 33. — This chart can be employed to determine the approxi- 

 mate tensile strength and percentage elongation in 2 in. of oxygen-free 

 copper strip when only Rockwell hardness is known. It is accurate 

 for all thicknesses between 0.020 and 0.080 in. within the given 

 limits (99.94 % copper). 



