Accupro 775686 ER20 Collet Chuck CAT50 Taper Shank

Product Description

The ACCUPRO 775686 is an ER20 collet chuck designed for precision CNC milling and machining operations. It accepts ER20 collets with a clamping range of 0.039 to 0.511 inches and mounts via a CAT50 taper shank for positive, repeatable seating in compatible spindle interfaces. The chuck delivers a total indicator runout (TIR) of 0.0002 inches, supporting tight-tolerance work across a range of tooling diameters. A 6-inch projection positions cutting tools clear of workpiece fixtures, and through-coolant capability routes fluid directly to the cutting zone. This chuck is installed by CNC machinists and toolroom technicians in production and job-shop environments.

The 775686 is suited for vertical and horizontal machining centers equipped with CAT50 spindle tapers. The 6-inch projection makes it practical for deep-cavity milling, extended-reach operations, and setups where standard-projection holders would contact workholding components. Through-spindle and DIN flange coolant delivery keeps cutting temperatures controlled during high-speed runs. The chuck is balanced to 25,000 RPM, making it compatible with high-speed machining center spindles where imbalance-induced vibration would otherwise degrade surface finish or tool life.

Key Features

• ER20 collet system accepts tooling from 0.039 to 0.511 inches in diameter
• CAT50 taper shank for secure, repeatable spindle mounting
• 0.0002-inch TIR for precision, low-runout tool holding
• 6-inch projection for extended-reach and deep-cavity applications
• Through-coolant compatible via through-spindle and DIN flange delivery
• Balanced to 25,000 RPM for high-speed machining center use

Compatibility

Designed for use with CAT50 spindle-equipped CNC machining centers using the ER20 collet system. Collet nut diameter is 1.38 inches. Compatible collets must conform to ER20 standards.

Installation Notes

Installation should be performed by a qualified CNC machinist or toolroom technician. Ensure the machining center spindle is fully stopped and the tool-change circuit is disabled before inserting or removing the chuck. Clean the CAT50 taper and spindle bore of chips, coolant residue, and oil film before seating to achieve full contact and specified TIR. Torque the retention knob or drawbar to the machine manufacturer's specification; do not use an unspecified value.