G8635 Drill Bushing Bushing Type Slip Fixed Renewable Combination SF Inside Dia 0.228 In Outside Dia 1/2 In Inside Dia Tolerance .0001-+.0004 In Outside Dia Tolerance -0.0002 In Concentricity Tolerance .0003 In T.I.R. Max Overall Length 5/16 In Material 52100 Thru Hardened Finish Steel Drill Size #1 Hardness RC 62-64