Bowed E-Syle Ring System of Measurement Inch Location Style External Thickness 0.025 in Fits Shaft Diameter 5/16 in For Bore Diameter Not Applicable Fits Groove Diameter 0.25 in Fits Groove Width 0.047 in Fits Groove Depth 0.031 in Free Inside Diameter 0.243 in Free Outside Diameter 0.5 in Clearance Diameter 0.52 in Material Steel Finish Black Phosphate Material Grade/Class Not Graded Tensile Strength Not Applicable Ring Type E-Style External Ring Thickness Tolerance +/-0.002 in