Accupro 771066 End Mill Holder CAT40 1-1/2 Inch Hole

Product Description

The ACCUPRO 771066 is a CAT40 dual contact taper shank end mill holder designed for precision CNC milling applications. It accepts a 1-1/2 inch bore and delivers a 4.5 inch projection from spindle face to tool tip. The dual contact interface engages both the taper and the spindle face simultaneously, increasing rigidity and reducing runout compared to standard single-contact holders. Total indicator runout (TIR) is rated at 0.0002 inches, making this holder suitable for demanding finishing and high-speed operations. Through-spindle and DIN flange coolant delivery are both supported. This holder is installed by CNC machinists and toolroom technicians on machining centers equipped with CAT40 spindles.

This end mill holder is suited for vertical and horizontal machining centers running CAT40 tooling. The 4.5 inch projection accommodates deep-reach milling setups while the 3 inch nose diameter provides a stable clamping platform. With a balanced speed rating of 30,000 RPM, it is compatible with high-speed spindle applications. The through-coolant feature supports flood and through-tool coolant strategies for extended tool life in ferrous and non-ferrous materials. A 5/8-11 retention knob thread is required for proper spindle engagement.

Key Features

• Dual contact taper interface engages both taper and spindle face for increased rigidity
• TIR of 0.0002 inches supports tight-tolerance and finishing operations
• Through-spindle and DIN flange coolant delivery compatible
• Balanced to 30,000 RPM for high-speed machining centers
• 1-1/2 inch bore with 2.55 inch clamping depth for secure tool retention
• 5/8-11 retention knob thread matches standard CAT40 spindle pull studs

Compatibility

Designed for use in CAT40 dual contact spindles on CNC vertical and horizontal machining centers. Requires a 5/8-11 retention knob for spindle mounting.

Installation Notes

Installation should be performed by a qualified CNC machinist or toolroom technician. Power down and lock out the machining center spindle before inserting or removing the holder. Verify that the taper bore and spindle taper are clean and free of chips or coolant residue before seating the holder, as contamination will affect TIR and dual contact engagement. Torque the end mill set screw to the tool manufacturer specification using the appropriate hex key.