Accupro 772066 End Mill Holder CAT40 3/4 Inch Bore

Product Description

The ACCUPRO 772066 is a CAT40 taper shank end mill holder designed for use in CNC machining centers requiring precise tool holding and through-coolant capability. The holder features a 3/4 inch bore and a 1.75 inch projection, positioning the cutting tool at a consistent working distance from the spindle face. A total indicator runout (TIR) of 0.0002 inch ensures tight concentricity tolerances, making this holder suitable for finish milling, profiling, and other operations where tool accuracy directly affects part quality. The retention knob thread is 5/8-11, the standard size for CAT40 tooling systems. This holder is installed by CNC machinists and toolroom technicians.

This end mill holder is suited for vertical and horizontal CNC machining centers equipped with a CAT40 spindle interface. The through-coolant design supports both through-spindle and DIN flange coolant delivery, allowing coolant to reach the cutting edge directly. This is especially useful in deep-pocket milling, slotting, and operations using high-pressure coolant systems. The 1-3/16 inch nose diameter and 1.77 inch clamping depth accommodate standard end mills with 3/4 inch straight shanks. Balanced to 30,000 RPM, this holder is appropriate for high-speed machining applications where spindle balance is critical to surface finish and spindle bearing longevity.

Key Features

• CAT40 taper shank for compatibility with standard CAT40 CNC spindles
• 3/4 inch bore diameter with 1.77 inch clamping depth for secure tool retention
• TIR of 0.0002 inch for high concentricity and dimensional accuracy
• Through-coolant compatible via through-spindle and DIN flange delivery
• Balanced to 30,000 RPM for high-speed machining operations
• 5/8-11 retention knob thread — standard for CAT40 tool holders

Compatibility

Designed as an OEM-style replacement or direct-use tool holder for CNC machining centers with a CAT40 spindle interface and through-coolant capability.

Installation Notes

Installation should be performed by a qualified CNC machinist or toolroom technician. Power down and lock out the machining center spindle before mounting or removing any tool holder. Use a torque wrench and the appropriate CAT40 pull stud when seating the holder in the spindle to ensure proper draw bar engagement. Inspect the taper shank and spindle bore for contamination or damage before each use, as debris on the mating surfaces will increase runout and reduce clamping force.