Accupro 771850 Shrink-fit Tool Holder CAT40 3/8 Inch

Product Description

The ACCUPRO 771850 is a shrink-fit tool holder adapter designed for CNC machining centers using CAT40 taper spindles. It accepts a 3/8 inch bore diameter and delivers a 3.15 inch projection, making it well suited for applications that require precise radial runout control and high clamping force without mechanical collet components. The shrink-fit design thermally expands the bore for tool insertion, then contracts on cooling to grip the cutting tool along the full clamping depth. Balanced to 30,000 RPM, this holder supports high-speed machining operations where vibration and runout directly affect surface finish and tool life. Through-coolant capability allows directed coolant delivery to the cutting zone.

This holder is intended for use in CNC vertical and horizontal machining centers equipped with CAT40 spindle interfaces. Typical applications include high-speed finish milling, drilling, and reaming where concentricity and balance are critical. The 1.65 inch clamping depth provides secure grip on standard carbide shank tooling at 3/8 inch diameter. Installation and tool changes are performed by machinists or tooling setup technicians using a shrink-fit induction heater and appropriate toolholder fixtures. The 0.94 inch nose diameter is compatible with standard shrink-fit heating coils sized for this tool family.

Key Features

• CAT40 taper shank for direct spindle mounting on CAT40 machining centers
• 3/8 inch bore diameter with 1.65 inch clamping depth for secure carbide shank retention
• Balanced to 30,000 RPM for high-speed machining compatibility
• Through-coolant design directs coolant flow to the cutting tool tip
• 3.15 inch overall length and projection for extended reach applications
• 0.94 inch nose diameter compatible with standard shrink-fit induction coil sizing

Compatibility

Designed as an OEM-style shrink-fit tool holder for CNC machining centers with CAT40 spindle interfaces accepting 3/8 inch shank cutting tools.

Installation Notes

Installation requires a shrink-fit induction heater and appropriate heating coil sized to the 0.94 inch nose diameter — never use an open flame to heat the holder. Insert the cutting tool to the correct clamping depth before the bore contracts on cooling. Ensure the holder is fully cooled to ambient temperature and inspect for proper tool seating before mounting in the spindle. Follow the machine tool manufacturer guidelines and applicable shop safety procedures when handling heated toolholders.