Allied Machine and Engineering HYD-CV40I1000 Hydraulic Tool Holders & Chucks; Shank Type: Taper ; Taper Size: CAT40 ; Hole Diameter (Inch): 1 ; Hole Diameter (Decimal Inch): 1.0000 ; Shank Diameter (Decimal Inch): 1.7500 ; Shank Diameter (mm): 44.450