Abstract: Improved wear interface surfaces on well rod centralizers and centralizer stops. Well apparatus includes a rotary tool in a string of tubing extending into a well hole in the earth and a rod extending to the ground surface through such tubing which is drivingly connected to the tool. Centralizers are used on the rod and are located between a pair of centralizer stops. The stops and centralizers associated therewith having wear interface surfaces and at least one of the wear interface surfaces which abut one another having a material thereon of a hardness in the range of 7 to 10 in Mohs scale of hardness and thereby having a hardness greater than the hardness of abrasive materials likely, during use, to pass through said tubing.

Abstract: A well pump sucker rod scraper arrangement that includes a sucker rod, scrapers fixed to said rod and a scraper at spaced apart positions movably mounted on said rod, between adjacent pairs of the fixed scrapers. The movable and fixed scrapers each have surfaces at respective opposite ends thereof and an outer fluted surface. The fluted surface is defined by spaced apart ribs and the ribs on the movable scraper are angularly disposed relative to the longitudinal axis of the rod. The movable scraper has a slot lengthwise thereof with a throat portion whose width is narrower than the diameter of the rod and through which the rod passes when pressing such movable scraper onto the rod. A lug on the fixed scrapers project therefrom in a direction toward an adjacent movable scraper and the lugs are so positioned so as to project into said slot of a movable scraper associated therewith as the latter approaches the fixed scraper and prior to engagement of the abutting planar end surfaces on the respective scrapers.