Chemical Composition (%)
| Sn | 4.0~6.0 |
|---|---|
| Pb | 18.0~23.0 |
| Cu | Balance |
Mechanical & Physical Properties
| Tensile strength | ≥150 MPa (chill cast) |
|---|---|
| Elongation | ≥6% (chill cast) |
| Hardness | ≥55 HBW (chill cast) |
| Density | 9.3 g/cm³ |
Typical Applications
Grade Overview
A high-lead, low-tin lead bronze for ordinary-machinery sliding bearings, bearing shells and bushings running at low speed under heavy load. With around 20% lead the alloy has very strong lubricity, conformability and embeddability, resists seizure and shock, and will keep running under starved or boundary lubrication; the tin is mainly there to restore some strength, giving a sand-cast tensile strength of about 150 MPa. Strength and hardness are clearly low - about 55 HBW in chill castings - so only limited loads can be carried, and it heats up quickly if speed is raised. Confine it to low-to-moderate speed, heavy, steady loads, match it to a suitable journal hardness, and check the environmental and duty limits on high-lead material. Lead segregates readily by density, so control pouring temperature and cooling rate. It is usually cast into a shell or bush rather than used as a solid bearing, and generous lubrication keeps the film stable at the speeds it is designed for; the alloy is also comparatively dense.
Data compiled from current standards; for selection reference only. Ordering is subject to the standard and the mill certificate.