Retaining Ring External 0.015 in Thk PK50 System of Measurement Not Applicable Location Style External Thickness 0.015 in Fits Shaft Diameter 1/4 in For Bore Diameter Not Applicable Fits Groove Diameter 3.71 in Fits Groove Width 0.12 in Fits Groove Depth Not Applicable Free Inside Diameter Not Applicable Free Outside Diameter 0.522 in Clearance Diameter 0.25 in Material Steel Finish Plain Material Grade/Class Ungraded Tensile Strength Not Applicable Ring Type Retaining Ring