Accupro 771238 Shell Mill Holder CAT50 1.5 Inch Pilot

Product Description

The ACCUPRO 771238 is a CAT50 shell mill holder with a dual contact taper shank, designed for use on CNC machining centers requiring high-rigidity face-and-taper contact. The holder accepts shell mills with a 1.5 inch pilot diameter and covers a cutting diameter range of 4 to 5 inches. Overall length is 12 inches, with a flange-to-nose projection of 8 inches. Through-coolant capability is standard, delivered via both through-spindle and DIN flange coolant ports. Total indicator runout (TIR) is rated at 0.0002 inches, supporting precision milling applications where concentricity directly affects surface finish and tool life.

This holder is suited for heavy-duty face milling, shoulder milling, and other shell mill operations performed on CAT50-spindle machining centers in metalworking shops and production environments. The dual contact design increases radial and axial rigidity compared to single-contact CAT taper holders, making it appropriate for high-feed applications and machines balanced to 10,000 RPM. The lock screw thread size is 3/4-16. Installation is performed by qualified CNC machinists and tooling technicians.

Key Features

• CAT50 dual contact taper shank for enhanced rigidity at the spindle interface
• 1.5 inch pilot diameter accepts shell mills in the 4 to 5 inch cutting diameter range
• Through-coolant delivery via both through-spindle and DIN flange ports
• TIR of 0.0002 inches for precision concentricity in milling operations
• Balanced to 10,000 RPM for compatibility with higher-speed spindle applications
• Lock screw thread size of 3/4-16 for positive shell mill retention

Compatibility

Designed for use with CAT50-spindle CNC machining centers accepting dual contact taper toolholders and shell mills with a 1.5 inch pilot bore in the 4 to 5 inch cutting diameter range.

Installation Notes

Installation and removal should be performed by a qualified machinist or tooling technician with the machine powered off and the spindle fully stopped. Use the appropriate spanner wrench or retention knob tool specified for CAT50 tooling — do not overtighten the retention knob by impact or improvised methods. Verify coolant port alignment with the spindle coolant system before operation. Inspect the taper shank and spindle bore for damage or contamination before mounting to avoid compromising runout performance.