Bronze properties
Bronze is a copper alloy, traditionally with tin, valued for its hardness, wear resistance, and low friction. Phosphor bronze, shown here, is widely used for bearings, bushings, springs, and marine parts. Properties vary with alloy and temper.
Mechanical properties
| Property | Value |
|---|---|
| Yield strength | 28 ksi (195 MPa) |
| Ultimate tensile strength | 50 ksi (345 MPa) |
| Elongation | 40% |
| Hardness | about 80 HRB (Rockwell B) |
| Modulus of elasticity | 15,900 ksi (110 GPa) |
Physical properties
| Property | Value |
|---|---|
| Density | 0.320 lb/in³ (8860 kg/m³) |
| Melting point | about 950 to 1050 °C |
Thermal properties
| Property | Value |
|---|---|
| Thermal conductivity | 69 W/m·K |
| Thermal expansion | 18.2 µm/m·°C |
| Specific heat | 380 J/kg·K |
Values are typical for the grade and condition shown. Actual properties vary with temper, heat treatment, and product form, so use these for comparison and preliminary design and confirm against material certificates for final work.
Compare with other materials
See the Material Properties Comparison, Yield Strength, and Density charts.
Typical uses
Bronze is used for bearings, bushings, gears, marine hardware, springs, and bells. Its low friction and wear resistance make it the classic bearing metal, and its corrosion resistance in seawater suits propellers and fittings.
How it compares
Bronze is harder, stronger, and more wear resistant than brass, and more corrosion resistant in seawater, but harder to machine and more expensive. Against steel it is softer but far better as a low-friction bearing surface and immune to rust.
FAQ
What is bronze made of?
Mainly copper with tin, often plus phosphorus, aluminum, or silicon. The additions tune hardness, strength, and corrosion resistance for the use.
Why is bronze used for bearings?
It combines hardness, wear resistance, and a low-friction surface that runs well against steel shafts, often holding oil in its pores.
Is bronze better than brass?
For bearings, wear, and seawater, yes. For machinability, color, and cost, brass is often preferred. The right choice depends on the use.