The sleeves/bushes/bushings and shafts in silicon carbide/sic,ssic/sintered silicon carbide,tungsten carbide/TC and the sleeve/bushing/bush & shaft of ceramic 99%/aluminium oxide 99%, ceramic 99.5%/aluminium oxide 99.5% and carbon/graphite are widely used in the magnetic pumps, shield pumps, multistage pumps, hydraulic pumps, chemical pumps, centrifuges and so on for ceramic has a low friction and a good resistance to wear.