G4665 Drill Bushing Bushing Type Headless Press Fit P Inside Dia 8.1mm Outside Dia 3/4 In Inside Dia Tolerance .0001-+.0005 In Outside Dia Tolerance +0.0015 - +0.0018 In Concentricity Tolerance .0003 In T.I.R. Max Overall Length 1/2 In Material 52100 Thru Hardened Finish Steel Drill Size 8.1mm Hardness RC 62-64