Accupro 771208 CAT50 Shell Mill Holder 0.75 in Pilot

Product Description

The ACCUPRO 771208 is a CAT50 dual contact taper shank shell mill holder designed for use on machining centers equipped with CAT50 spindles. It accepts shell mill cutters through a 0.75 inch pilot diameter and features a 2 inch nose diameter to support cutters in the 1.75 to 2 inch cutting diameter range. The dual contact taper shank engages both the taper and the spindle flange face simultaneously, improving rigidity and reducing runout. Measured TIR is 0.0002 inches. Through-spindle and DIN flange coolant delivery channels are integrated, supporting high-pressure coolant applications. This holder is balanced to 10,000 RPM. Installation is performed by qualified machinists or tool-room technicians.

This holder is suited for face milling and shell milling operations in production and job-shop environments running CAT50-equipped vertical or horizontal machining centers. The 1.75 inch flange-to-nose projection keeps the cutter close to the spindle face, reducing overhang and improving chatter resistance in interrupted cuts or harder materials. Coolant delivery through both the spindle bore and DIN flange ports makes it compatible with machines plumbed for through-spindle coolant. The lock screw uses a 3/8-24 thread for securing the shell mill to the holder nose.

Key Features

• CAT50 dual contact taper shank for simultaneous taper and face contact, improving stiffness over standard V-flange holders
• 0.75 inch pilot diameter accepts standard shell mill cutter bores in the 1.75 to 2 inch cutting diameter range
• TIR of 0.0002 inches for consistent cutter runout performance
• Through-spindle and DIN flange coolant delivery for chip evacuation and tool life in high-pressure coolant setups
• Balanced to 10,000 RPM for use at higher spindle speeds without excessive vibration
• Lock screw thread size 3/8-24 for secure cutter retention

Compatibility

Designed for use with CAT50 dual contact taper spindles on vertical and horizontal machining centers. Accepts shell mill cutters with a 0.75 inch pilot bore in the 1.75 to 2 inch cutting diameter range.

Installation Notes

Installation and tool changes must be performed with the machine spindle fully stopped and the machine control in a locked-out state per applicable shop safety procedures. Inspect the spindle taper and holder taper for nicks, burrs, or contamination before seating; even minor debris will affect dual contact engagement and runout. Torque the shell mill lock screw to the cutter manufacturer's specification using a calibrated torque wrench. Verify runout with a dial indicator after mounting before taking the first cut.