Accupro 777674 BT40 Milling Chuck 3/4 in Through Coolant

Product Description

The ACCUPRO 777674 is a BT40 taper milling chuck designed for CNC machining centers that require secure tool holding with integrated through-coolant delivery. The chuck accepts a 3/4 inch (0.7500 inch) hole diameter and features a 2.05 inch nose diameter with a 4.13 inch projection length. It achieves a total indicator reading (TIR) of 0.0002 inch, making it suitable for precision milling operations where runout control is critical. The unit is balanced to 10,000 RPM and supports both through-spindle coolant and DIN flange coolant configurations. Machinists and CNC setup technicians typically install and service this toolholder.

This chuck is suited for use in BT40-spindle CNC vertical and horizontal machining centers across production and job-shop environments. It is commonly used in applications involving end mills, reamers, and similar cutting tools requiring a collet-style chuck interface. The 3.15 inch clamping depth provides solid tool engagement for demanding metal removal operations. Through-coolant capability makes it effective in applications where chip evacuation and tool cooling at the cutting zone are priorities.

Key Features

• BT40 taper shank for direct spindle interface on BT40-equipped machining centers
• 3/4 inch (0.7500 inch) hole diameter for standard end mill and tooling shanks
• TIR of 0.0002 inch for precision runout control during milling operations
• Balanced to 10,000 RPM for stable high-speed machining
• Through-spindle and DIN flange coolant compatibility for improved chip evacuation and tool life
• 3.15 inch clamping depth for secure tool engagement and reduced pullout risk

Compatibility

Designed as an OEM-style toolholder for CNC machining centers equipped with a BT40 taper spindle interface.

Installation Notes

Installation and tool changes should be performed by a qualified machinist or CNC setup technician with the spindle powered down and the machine in a safe, locked-out state per facility lockout/tagout procedures. Use an appropriate BT40 retention knob and torque the drawbar or toolholder retention mechanism according to the machining center manufacturer specifications. Verify runout with a dial indicator after seating the chuck before initiating any cutting operation. Inspect the taper bore and spindle taper for contamination or damage before each installation.