INDUSTRIAL GRADE H6412NC G2798 Drill Bushing Bushing Type Head Press Fit H Inside Dia. 3/4 In Outside Dia. 1 In Inside Dia. Tolerance +.0001- +.0005 In Outside Dia. Tolerance +0.0018 - +0.0015 In Concentricity Tolerance .0005 In T.I.R. Max Overall Length 3/4 In Material 52100 Thru Hardened Finish STEEL Drill Size 3/4 In Hardness RC 62-64