G2780 Drill Bushing Bushing Type Head Press Fit H Inside Dia 3/8 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 5/16 In Material 52100 Thru Hardened Finish STEEL Drill Size 3/8 In Hardness RC 62-64