Shank Type: Taper Shank Taper Size: CAT50 Pilot Diameter (Inch): 1 Pilot Diameter (Decimal Inch): 1.0000 Projection Flange to Nose End (Decimal Inch): 2.0000 Through Coolant: Yes Nose Diameter (Decimal Inch): 2.2500 Balanced to (RPM): 30000 Shell Mill Cutting Diameter Range (Inch): 2-1/4 – 2-3/4 TIR (Decimal Inch): 0.0002 Coolant Type: Through-Spindle Lock Screw Thread Size: 1/2-20