Small caliber tin-bronze ring was produced by vertical centrifugal casting based on its structure and size features. A series of parameters

such as preheating temperature of mould

rotation velocity

pouring temperature and pouring speed

were determined for vertical centrifugal casting. Melting process of ZQSn10-1 alloy was made up and the small caliber tin-bronze ring was produced. Microstructure and mechanical properties of the ring were analyzed by OM （optical microscope） and tensile testing. Effects of filtration of liquid alloy and water cooling process for mould on surface quality

microstructure and properties of the ring were described. The results indicate that gas hole and inclusion defects in surface of the ring can be greatly eliminated by filtering liquid alloy. Grain size in the ring can be distinctly refined by water cooling for mould

which is responsible for the obvious improvement of hardness and tensile strength of the ring.