Accupro 772120 End Mill Holder CAT50 3/8 Inch Through Coolant

Product Description

The ACCUPRO 772120 is a CAT50 taper shank end mill holder designed for CNC machining centers requiring high-speed, precision toolholding. It accepts a 3/8 inch bore and delivers a 4 inch projection from the spindle face, allowing access to workpieces where clearance is a factor. The nose diameter measures 1 inch. Total indicated runout (TIR) is rated at 0.0002 inches, supporting tight tolerances in milling operations. The holder is balanced to 25,000 RPM, making it suitable for high-speed machining applications. Through-spindle and DIN flange coolant delivery is supported, directing coolant directly to the cutting zone for improved chip evacuation and tool life.

This end mill holder is used in production and job-shop environments where CAT50 spindle tooling is standard. It is appropriate for vertical and horizontal machining centers running end mills in ferrous and non-ferrous materials. The 4 inch projection and 1.26 inch clamping depth provide secure tool retention across a range of end mill shank lengths. Machinist technicians and CNC setup personnel are the primary installers. The retention knob thread size is 1-8, which is standard for CAT50 tooling assemblies.

Key Features

• CAT50 taper shank for direct spindle mounting on compatible machining centers
• 3/8 inch bore accepts standard end mill shank sizes
• TIR of 0.0002 inches for precision concentricity
• Balanced to 25,000 RPM for high-speed machining compatibility
• Through-spindle and DIN flange coolant delivery directs fluid to the cutting edge
• Retention knob thread size 1-8, standard for CAT50 systems

Compatibility

Designed as an OEM-style toolholder for CAT50 spindle machining centers using standard 1-8 retention knob thread configurations. Accepts end mills with a 3/8 inch straight shank.

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 any toolholder. Use a torque wrench and the machine manufacturer's specified retention knob procedure — do not rely on hand-tightening alone. Verify TIR with a dial indicator after installation before running the spindle.