84 



Table M. 



MECHANICAL PROPERTIES OF MATERIALS- 



TABLE 64. — Copper-zinc Alloys or Brasses; Tin Alloys or Bronzes. 



Compressive Strengths, Brasses: 



Cu 90, Zn 10, cast 21.0 kg/mra^ or 30,000 lb/in* 

 Cu 80, Zn 20, cast 27.4 kg/mm^ or 39,000 lb/in* 

 Cu 70, Zn 30, cast 42.0 kg/mm^ or 60,000 lb/in* 

 Cu 60, Zn 40, cast 52.5 kg/mm^ or 75,000 lb/in* 

 Cu 50, Zn 50, cast 77.0 kg/rrtm^ or 110,000 lb/in' 



Modulus of elasticity, — cast brass, — average 9100 kg/mm^ or 13,000,000 Ib/'vn? 



Erichsen values: Soft slab, 1.3 mm (0.05 in.) thick, no rolling, depth of impression 13.8 mm (0.55 in.). 



Hard sheet, 1.3 mm, rolled 38% reduction, depth of impression 7.3 mm (0.29 in.). 



Hard sheet, 0.5 mm, rolled 60% reduction, depth of impression 3.7 mm (0.15 in.). 



Compressive Ultimate Strengths, Cast Bronzes: 



Cu 97.7, Sn 2.3 to 24.0 kg/mm2 or 34,000 lb/in* 

 Cu 90, Sn 10 to 39.0 kg/mm2 or 56,000 \h/irfi 

 Cu 80, Sn 20 to 83.0 kg/mm^ or 11 8, 000 Ib/in^ 

 Cu 70, Sn 30 to 105.0 kg/mm' or 150,000 Ib/in^ 



Specification value, A. S. T. M., B 22-18 T, for specimen = cylinder 645 sq. mm (i sq. in.) area, 25.4 mm (i in.) 

 long. 



Cu 80, Sn 20: minimum compressive elastic limit = 17.0 kg/mm^ or 24,000 Ib/in^ 



Modulus of elasticity for bronzes varies from 7000 kg/mm' or 10,000,000 Ib/in^ to 10,000 kg/mm' or is,soo,oo<» 

 lb/in2 



* Values marked thus are S. A. E. Spec, values. (See S. A. E. Handbook, Vol. I, p. 13a, rev. December, 1913. 

 t Red metal. t Low brass or bell metal. 



§ A. S. T. M. Spec. B19-1ST requires B.h.n. of 51-6$ kg/mm^ @ 5000 kg pressure for 70: 30 annealed shee^ 

 brass. 



Foot notes to Table 65, Page 85. 



♦Tensilite, Cu 67, Zn 24, Al 4.4, Mn 3.8, P o.oi compressive P-limit: 42.2 kg/mm' or 60,000 lb/in» and 1.33 per 

 cent set for 70.3 kg/mm^ or 100,000 Ib/in^ load. 



t Compressive P-limit 20.0 to 28.2 kg/mm' or 28,500 to 40,000 lb/in' 



I Compressive ultimate strength 54.5 kg/mm- or 77,500 Ib/in^ 



§ Compressive P-limit 4.2 kg/mm^ or 6000 Ib/in^ and ao per cent set for 70.3 kg/mm* or 100,000 lb/in' 



II Modulus of elasticity 9840 kg/mm^ or 14,000,000 Ib/in^ 



1 1 Values are for yield point. ** Minimum values for ingots. 



ft Rolled manganese bronze (U. S. N.) Cu S7 to 60, Zn 40 to 37, Fe max. 2.0, Sn 0.5 to i.s; 3-9 per cent increase 

 for thickness 25.4 mm (i in.) and under. 



it Ni 9 per cent, B.h.n. = 130 as rolled; B.h.n. = 50 as annealed at 930° C. . . ■ 



U. S. Navy Dept. Spec. 46S 3a, June i, 1917: German silver Cu 60 to 67, Zn 18 to 22, Ni min. 15, no m«chamcal 

 requirements. 



For list of 30 German silver alloys, see Braunt, "Metallic Alloys," p. 314, — "best" (Hioms), "hard SheflBeld," 

 Cu 46, Zn 20, Ni 34. 



§1 Platinoid Cu 60, Zn 24, Ni 14, W i to 2; high electric resistance alloy with mechanical properties as nickel brass. 



nil Specification Values, Naval Brass Castings, U. S. Navy, 46B lob, Dec. i, 1917 for normal proportions Cu 62, Zn 

 37, Sn I, min. tensile strength 17.5 kg/mm' or 35,000 lb/in* wili ij per cent elongation in 50.8 mm {2 in.). 



Smithsonian Tables. 



