A submersible well pump has a rotatable drive shaft extending through pump stages. Each of the stages has a diffuser, an impeller and a bushing fixed for non-rotation in the diffuser. A thrust member has a lower side in sliding rotating engagement with the upward facing surface of the bushing. The bushing and the thrust member are of a harder material than the diffuser and the impeller. A drive member of a softer material than the thrust member is in engagement with the thrust member and has a drive member bore through which the shaft extends. A key extends through the shaft groove, the impeller groove and the drive member groove to cause the impeller and thrust member to rotate with the shaft.