C51000 (ASTM B103) Alloy Data Specifications

The "work horse" of the phosphor bronzes, alloy C510 combines strength, toughness and good ductility with excellent resistance to fatigue. Additional advantages of a high elastic limit, good resistance to corrosion and corrosion-fatigue make this alloy an optimal choice for designers considering active spring applications including: mechanical springs, electrical contact springs, terminals, diaphragms and bellows. For more information contact Olin Brass Market Development Engineering at 618-258-5255, OlinBrass.com or email us at info@olinbrass.com.

Chemical Composition

Copper1 Remainder
Tin 4.2-5.8%
Phosphorus 0.03-0.35%
Lead 0.05% max
Iron 0.10% max
Zinc 0.30% max

1Copper plus named elements, 99.5% min

Physical Properties

  English Units Metrics Units
Density 0.320 lb/in3 @ 68oF 8.86 g/cm3
Thermal Conductivity 40 BTU-ft/ft2-hr-oF 69 W/moK
Electrical Resistivity 69.1 ohm circ mils/ft 11.5 microhm-cm
Electrical Conductivity (annealed) 15% IACS* 0.087 megamho/cm
Modulus of Elasticity 16,000,000 psi 110 kN/mm2
Thermal Capacity (Specific Heat) 0.090 Btu/lb/Fo @ 68oF 0.090 cal/gm/Co @ 20oC
Coeff. of Thermal Expansion
  68-572oF (20-300oC) 9.90 PPM/oF 17.82 PPM/oC

*International Annealed Copper Standard

Mechanical Properties

Temper1 Tensile Strength Yield Strength2 % Elongation2 Typical 90o Bend Formability GW/BW3
ksi N/mm2 ksi N/mm2
Annealed 46-56 315-385 24 165 55 - -
1/4 Hard 49-61 340-420 37 255 41 - -
1/2 Hard 58-73 400-505 57 395 24 - 0.5
3/4 Hard 68-79 470-545 68 470 15 0.5 1.0
Hard 76-91 525-625 81 560 10 1.0 1.5
Extra Hard 88-103 605-710 93 640 4 1.5 2.5
Spring Hard 95-110 655-760 100 690 2 2.0 5.0
Extra Spring 100-114 690-785 104 715 2

1Mechanical properties subject to change. All tempers listed are made to a Tensile Strength specification unless otherwise noted.
2Nominal Values
3DATA FOR REFERENCE ONLY. R/T = Bend Radius/Material Thickness <0.016" (0.4mm) thick, 11/16 (17.5mm) wide. Relief annealed tempers.