Milling Boring Head Set With MT3 Shank Diameter 38mm (1.5") High Precision Boring Head for Milling Machine of Head Diameter 38 mm Supplied with 3MT (Arbor's Drawbar - M12 x 1.75) , Arbor's Mounting Thread - M14 x 1, Arbor's Shank - MT3 / 3MT / Morse Taper 3 Head diameter - 38mm Capacity with vertical tool - 0-38mm Maximum boring diameter excluding tool - 60mm For tooling diameter - 8mm 1 Division: 0.015 mm Accepts 8 mm diameter tooling Supplied with 3 Carbide brazed boring bars.