Chemical Composition (%)
| Sn | 4.0~6.0 |
|---|---|
| Pb | 4.0~6.0 |
| Zn | 4.0~6.0 |
| Cu | Balance |
Mechanical & Physical Properties
| Tensile strength | ≥200 MPa (chill cast) |
|---|---|
| Elongation | ≥13% (chill cast) |
| Hardness | ≥60 HBW (chill cast) |
| Density | 8.8 g/cm³ |
Typical Applications
Grade Overview
The classic three-element balanced tin bronze, with roughly 5% each of tin, lead and zinc, widely used for bearing shells, bushings, cylinder liners, pump parts, valves and worm wheels. Lead sits as a soft phase that improves machinability and sliding behaviour; zinc strengthens in solid solution and improves casting characteristics. The result is good ductility, high pressure tightness and easy machining, with a sand-cast tensile strength of at least 200 MPa and elongation of at least 13%, giving excellent all-round fabricability at a favourable cost. Its weakness is modest strength and hardness: only about 60 HBW in chill castings, so it is unsuitable for high loads or high sliding speeds. Choose it for wear- and corrosion-resistant parts under moderately high load and moderate speed. Lead restricts use in drinking water, food contact and some export markets, so confirm compliance before specifying it. Steady, well-lubricated service at moderate speed plays to its strengths, while high-speed or heavily loaded bearings should be moved to a higher-tin or aluminium bronze.
Data compiled from current standards; for selection reference only. Ordering is subject to the standard and the mill certificate.