C42500 (ASTM B591) Alloy Data Specifications

Originally developed as a "bearing bronze," C425 provides a low coefficient of friction plus a high work-hardening rate making the alloy an excellent choice for use in bearing surfaces. In addition this economical spring alloy provides maximum resistance to corrosion and excellent fatigue strength. Like other tin brasses C425 provides an excellent option for a wide range of applications and is typically found in automotive terminals and other electrical connectors. 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 87.0-90.0%
Tin 1.5-3.0%
Zinc Remainder
Iron 0.05% max
Lead 0.05% max
Phosphorus 0.35% max

1Copper plus named elements, 99.7% min

Physical Properties

  English Units Metrics Units
Density 0.317 lb/in3 @ 68oF 8.78 g/cm3
Thermal Conductivity 69 BTU-ft/ft2-hr-oF 121 W/moK
Electrical Resistivity 37.0 ohm circ mils/ft 6.20 microhm-cm
Electrical Conductivity (annealed) 28% IACS* 0.161 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 (20-300o) 10.2 PPM/oF 18.36 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 41-47 285-325 17 115 48 - -
1/4 Hard 49-59 340-405 37 255 35 - -
1/2 Hard 57-69 395-475 58 400 20 - -
3/4 Hard 62-74 425-510 64 440 15 - 0.5
Hard 70-82 485-565 72 495 9 0.3 1.5
Extra Hard 76-88 525-605 79 545 6 0.5 2.0
Spring Hard 84-94 580-650 90 620 4 0.8 3.0
Extra Spring 92 min 635 min 87 min 600 min 2 max

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.