APPENDIX B 

 DEFINITION OF TERMS 



1. Apparent Elastic Limit. — See Test Methods, 

 Appendix A. 



2. B. & S. Numbers Hard. — In the fabrication of 

 wrought copper-base alloy sheet and strip, it is common 

 practice to refer to the amount of cold work performed 

 as the B. & S. Nos., hard, e.g., sheet and strip thicknesses 

 are based on Brown and Sharpe gage units. If a copper- 

 base alloy is cold-roUed from 12 B. & S. gage (0.0808 in.) 

 to 13 B. & S. gage (0.0720 in.), it is said to be 1 No., hard; 

 if from 12 B. & S. gage (0.0808 in.) to 16 B. & S. gage 

 (0.0508 in.) , 4 Nos. hard. The relation between numbers 

 hard, percentage reduction of area by cold working, and 

 commercial temper designations is given in the following 

 table: 



Commercial temper cold-rolled 

 sheet and strip 



& S. Nos., 

 Hard 



Quarter hard 



Half hard 



Three-quarters hard 



Hard 



Extra hard 



Spring 



Extra spring 



Reduction 

 of area, % 



10.9 

 20.7 

 29.4 

 37.1 

 50.0 

 60.5 

 68.7 



3. Ready-to-fimsh Anneal and Ready-to-finish Grain 

 Size. — In the cold-working as well as in the annealing 

 charts for wrought copper-base alloy strip, it will be 

 observed that complete mechanical properties are given 

 for two different "ready-to-finish' grain sizes. In 

 brass mill terminology it is common practice to refer to 

 the anneal before the final cold working as the "ready- 

 to-finish" anneal and the grain or crystal size of the 

 metal obtained as the "ready-to-finish" gi-ain size. 

 Others have referred to it as the penultimate anneal or 

 grain size. In all cases where properties are given for 

 two different "ready-to-finish" grain sizes, the values 

 selected have been those commonly encountered in the 

 commercial production of the material in question. 



4. Relief Anneal or Stress Reliefing. — It is common 

 practice with certain of the wrought copper-base alloys 

 to anneal them at a temperature below the recrystalUza- 

 tion or equicohesive temperature to distribute or 

 normalize residual internal stresses produced by previous 

 cold-working operations. Relief annealing usually has 

 very little influence on mechanical properties produced 

 by previous cold work, though in some cases a definite 

 improvement in elastic properties is effected. Copper- 

 base alloys that have been properly relief-annealed offer 

 much greater resistance to stress-corrosion cracking 

 (season craclcing) than do untreated materials. 



