Chemical Composition (%)
| Pb | 27.0~33.0 |
|---|---|
| Sn | ≤1.0 |
| Cu | Balance |
Mechanical & Physical Properties
| Hardness | ≥25 HBW (chill cast) |
|---|---|
| Density | ≈9.6 g/cm³ |
Typical Applications
Grade Overview
The highest-lead grade of the cast lead bronzes, used for high-speed light-load bearings, bimetal bearing shells and bushings. The very high lead content gives outstanding anti-friction behaviour, conformability and embeddability, and the alloy relies almost entirely on the oil film to carry load; seizure resistance is excellent, with a chill-cast hardness of only about 25 HBW. Strength and hardness are the lowest in the series and the castings are heavy, so it cannot carry substantial load on its own. It suits high-speed, light-load duties, or thin anti-friction linings bonded to a steel backing. Ensure generous oil supply, avoid dry running and overload, and observe the environmental and occupational-health requirements that apply to high-lead alloys; because of its low strength it is normally used in combination with a steel backing rather than as a structural part. Machining is easy because the lead phase is soft, but the low strength means the alloy is essentially a bearing lining material and not a load-carrying structural casting.
Data compiled from current standards; for selection reference only. Ordering is subject to the standard and the mill certificate.