Accupro 771120 CAT50 End Mill Holder 1/2 Inch Bore

Product Description

The ACCUPRO 771120 is a CAT50 dual contact taper shank end mill holder designed for CNC machining centers requiring rigid, high-precision toolholding. It accepts a 1/2 inch bore and delivers a 4 inch projection from the spindle face, making it suitable for operations where extended reach is needed without sacrificing rigidity. The dual contact taper engages both the taper and the spindle face simultaneously, improving repeatability and reducing runout to 0.0002 inches TIR. Through-coolant capability supports both through-spindle and DIN flange coolant delivery. Overall length is 8 inches and the holder weighs 7.8 pounds. Installation requires a 1-8 retention knob thread size. This holder is installed by CNC machinists and toolroom technicians.

The ACCUPRO 771120 is intended for use on CNC vertical and horizontal machining centers equipped with CAT50 spindles. The 4 inch projection and 1-3/8 inch nose diameter make it appropriate for applications where clearance around the workpiece or fixture is a factor. Through-coolant support allows direct coolant delivery to the cutting zone, which is beneficial in high-speed cutting of ferrous and non-ferrous materials. The holder is balanced to 25000 RPM, making it compatible with high-speed spindle applications where dynamic balance is a requirement.

Key Features

• CAT50 dual contact taper shank engages both taper and spindle face for improved rigidity and repeatability
• 1/2 inch bore diameter with 1-1/2 inch clamping depth provides secure tool retention
• 4 inch projection suits extended-reach machining setups
• TIR of 0.0002 inches supports precision cutting operations
• Through-coolant compatible via through-spindle and DIN flange delivery
• Balanced to 25000 RPM for high-speed machining center use

Compatibility

Designed for use in CAT50 spindle machining centers. Accepts 1/2 inch shank end mills and compatible cutting tools. Retention knob thread size is 1-8.

Installation Notes

Installation is performed by CNC machinists or toolroom technicians during tool setup or changeout. Power down and lock out the machining center before handling spindle tooling. Use the appropriate torque wrench and CAT50-rated toolholder tightening fixture when seating the retention knob — refer to the machine tool manufacturer specifications for retention knob torque. Inspect the spindle taper and holder taper for contamination or damage before each installation to protect TIR performance.