contact with projections 51 and its skirt 21 located within cavity 54 lower support 53 will be in contact with outer thrust washer 25 plunger 61 is placed against the downstream end of impeller 13 with hub 15 located in passage 63 plunger 61 is stroked toward body 47 as illustrated in fig6 this causes projections 51 to embed into retaining wall rim 41 radially deforming inner and outer sides 37 39 fig3 this deformation also causes some deformation of thrust washer 25 creating an interference fit springs 57 allow lower support 53 to move downward slightly as plunger 61 moves impeller 13 further toward die 49 if a staking procedure is to be used with inner thrust washer 27 a different die assembly would be required as it would need to pass through skirt 21 and engage the retaining wall surrounding inner thrust washer 27 fig7 illustrates an alternate embodiment pump stage 65 is particularly to be used in abrasive applications such as where well fluid has an appreciable content of sand impeller 67 rotates within diffuser 69 an impeller thrust washer 71 is mounted to impeller 67 for transferring downward thrust to a diffuser thrust washer 73 that is stationarily mounted to diffuser 69 both thrust washers 71 73 are preferably formed of a hard wear resistant material such as tungsten carbide thrust washers 71 73 engage each other in rotating sliding contact referring to fig9 thrust washers 71 73 are identical in this embodiment each having an outer diameter containing a radially extending lip 75 also lip 75 of each thrust washer 71 73 has a plurality of flats 77 in this embodiment three flats 77 are shown spaced 120 u00b0 from each other each flat 77 extends.