Accupro 771218 Shell Mill Holder CAT50 1 Inch Pilot

Product Description

The ACCUPRO 771218 is a CAT50 dual contact taper shank shell mill holder designed for precision face milling and shell milling operations on CNC machining centers. The dual contact taper interface engages both the taper and the spindle face simultaneously, increasing rigidity and reducing runout compared to standard single-contact toolholders. This holder features a 1-inch pilot diameter and a nose diameter of 2.75 inches, accepting shell mills in the 2.25 to 2.75 inch cutting diameter range. Total indicated runout (TIR) is held to 0.0002 inches. Through-coolant capability is supported via both the spindle bore and the DIN flange, keeping the cutting zone clear during heavy material removal. This holder is installed by CNC machinists and toolroom technicians working in production or job shop environments.

The 771218 is suited for use on CAT50 spindle machining centers performing face milling, shoulder milling, or slot milling with shell mill cutters. The 4-inch projection from the flange to the nose end provides adequate clearance for most standard setups. The holder is balanced to 10,000 RPM, making it appropriate for high-spindle-speed roughing and semi-finishing operations in steel, aluminum, and other common workpiece materials. Lock screw thread size is 1/2-20. The overall length is 8 inches.

Key Features

• Dual contact taper shank engages both taper and spindle face for increased rigidity and reduced runout
• TIR of 0.0002 inches for precise, repeatable cutter positioning
• Through-coolant delivery via through-spindle and DIN flange ports
• Accepts shell mills with cutting diameters from 2.25 to 2.75 inches
• Balanced to 10,000 RPM for high-speed milling applications
• Lock screw thread size 1/2-20 for secure cutter retention

Compatibility

Designed for use with CAT50 dual contact taper spindle machining centers and compatible with shell mill cutters in the 2.25 to 2.75 inch cutting diameter range.

Installation Notes

Installation and removal should be performed by a qualified CNC machinist or toolroom technician with the spindle fully de-energized and the machine in a safe, locked-out state. Use the appropriate drawbar torque procedure specified by the machine tool manufacturer for CAT50 toolholders. Verify TIR at installation using a dial test indicator before committing to production cuts. Confirm coolant port alignment with the spindle coolant delivery system before engaging through-coolant flow.