D 1725 This is a 1-25/32 in. diameter concave or center grooved zinc plated steel ball bearing roller replacement used on a variety of patio and wardrobe door roller assemblies. It has a steel center race and a standard 1/4 in. axle hole and is 3/8 in. wide. Usually installed with a rivet into the inner roller housing. Zinc Plated Steel Roller. Ball Bearing. Concave (Grooved) roller .1-25/32 in. in diameter. 1/4 in. axle hole .3/8 in. wide or thick. Used on a variety of patio and closet door roller assemblies. For further dimensional information, please see the line drawing