Abstract: Improved wear interface surfaces on well rod stabilizers and stabilizer 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.