This kind of bush is wrapped by bimetal strip, the strip is based on steel backing
and incorporated with bronzed surface. The bronze layer is sintered twice under
high temperature and calendered firmly onto the steel strip.
| Item | Alloy Type | Cu | Pb | Sn | Zn |
| SL800 | Cu80Pb10S10 | 80 | 10 | 10 | / |
| SL750 | Cu70Pb10 | 75 | 24 | 1 | / |
| SL720 | Cu75Pb22S3 | 72 | 24 | 4 | / |