Accupro 775202 End Mill Holder BT40 5/16 Inch Through Coolant

Product Description

The ACCUPRO 775202 is a BT40 taper shank end mill holder designed for CNC machining centers that require precise toolholding with integrated coolant delivery. The holder features a 5/16 inch bore, a 7/8 inch nose diameter, and a 2.5 inch projection from gauge line to the front face of the holder. A total indicator runout (TIR) of 0.0002 inches ensures concentricity critical to achieving tight tolerances in milling operations. Coolant is delivered through-spindle and via DIN flange, making this holder suitable for high-speed cutting applications where chip evacuation and tool temperature management are essential. It is installed by CNC machinists and toolroom technicians.

This end mill holder is intended for use on BT40-spindle CNC vertical and horizontal machining centers in production and job shop environments. The 2.5 inch projection accommodates tooling setups where clearance over workpiece features or fixtures is required. The M16 x 2.0 drawbar thread is the standard interface for BT40 spindle retention systems. Balanced to 30,000 RPM, this holder supports high-speed machining strategies used in aerospace, mold and die, and general precision component manufacturing.

Key Features

• BT40 taper shank with M16 x 2.0 drawbar thread for standard BT40 spindle retention
• 5/16 inch bore diameter for compatible end mill shanks
• 2.5 inch projection for reach over fixtures or stepped workpiece features
• TIR of 0.0002 inches for high-concentricity toolholding
• Through-coolant via spindle and DIN flange for improved chip evacuation and tool life
• Balanced to 30,000 RPM for compatibility with high-speed machining centers

Compatibility

Designed as an OEM-style end mill holder for CNC machining centers equipped with a BT40 taper spindle and M16 x 2.0 drawbar thread.

Installation Notes

Installation should be performed by a qualified CNC machinist or toolroom technician following the machining center manufacturer's toolholder torque and retention procedures. Ensure the spindle and coolant supply are fully de-energized and depressurized before mounting or removing the holder. Inspect the taper bore and holder shank for burrs or contamination prior to seating, as surface irregularities directly affect runout. Verify drawbar engagement and retention force per the machine tool manufacturer's specifications before operation.