The Special Brasses 



181 



10 20 30 40 50 60 70 80 90 100 



Rockwell Hardness- B '/i6 Ball 100 Kg. Load 

 57 63 69 74 80 86 91 97 



Rockwell Hardness- F '/i6 Ball 60 Kg. Load 

 61 64 67 71 74 77 80 84 87 90 93 



Rockwell Hardness 15 T /le Ball 15 Kq. Load 

 15 22 29 36 43 50 57 64 70 76 82 



Rockwell Hardness 30T yieBall 30 Kg. Load 



Chart 13. — This chart can be employed to determine the approxi- 

 mate tensile strength and percentage elongation of silicon brass No. 1 

 strip (77.74 % copper, 1.30 % silicon, balance zinc) when only Rockwell 

 hardness is known. It is accurate for all thicknesses between 0.020 

 and 0.080 in. within the given limits. 



aoio 



0.002 0.004 0.006 0.008 



strain- Inches per In. 



Chakt 14. — The effect of cold rolling on the stress-strain character- 

 istics of silicon-brass No.'^l strip (0.040 in. thick) having a ready-to- 

 finish grain size of 0.015 mm.; 5,000-lb. capacity hydraulic testing 

 machine and Templin automatic extensometer accurate to 0.00001 in. 

 used. (77.74 % copper, 1.30 % silicon, balance zinc.) 



0.002 0.004 0.006 0.008 O.OIO 



5f rain, Inches per In. 

 Chakt 15. — The effect of cold rolling on the stress-strain characteristics of silicon-brass No. 1 strip (0.040 in. thick) having a ready-to- 

 finish grain size of 0.090 mm.; 5,000-lb. capacity hydraulic testing machine and Templin automatic extensometer accurate to 0.00001 in. used. 

 (77.74 % copper, 1.30 % silicon, balance zinc.) 



