Centralizers for stabilizing production tubing within a well may include a mandrel for securing within a section of production tubing and having a gland mounting surface; a gland mounted to the gland mounting surface of the mandrel, and having a cylindrical body and two or more lobes extending radially outward from the cylindrical body and comprised of an abrasion resistant material. Downhole assemblies may include a production string receivable within a cased well; a tubing anchor catcher positioned within the production string; a downhole pump coupled to the production string and located axially below the tubing anchor catcher; and a centralizer coupled to the production string.