G2788 Drill Bushing Bushing Type Head Press Fit H Inside Dia 31/64 In Outside Dia 3/4 In Inside Dia Tolerance +.0001- +.0005 In Outside Dia Tolerance +0.0018 - +0.0015 In Concentricity Tolerance .0003 In T.I.R. Max Overall Length 1-3/4 In Material 52100 Thru Hardened Finish STEEL Drill Size 31/64 In Hardness RC 62-64