Accupro 775205 End Mill Holder BT40 3/16 in Through Coolant

Product Description

The ACCUPRO 775205 is a BT40 taper shank end mill holder designed for CNC machining centers requiring precise tool holding with through-coolant capability. The holder accepts a 3/16 inch bore diameter and delivers a 4 inch projection from the spindle face, positioning cutting tools at the correct depth for a wide range of milling operations. With a total indicator reading (TIR) of 0.0002 inches, this holder maintains tight runout tolerances critical for finishing passes and small-diameter end mill applications. A 3/4 inch nose diameter and M16 x 2.0 drawbar thread complete the interface. Installation and use are appropriate for machinists and CNC operators working in job shop or production environments.

This end mill holder is suited for vertical and horizontal machining centers equipped with BT40 spindle interfaces. The through-coolant design supports both through-spindle and DIN flange coolant delivery, making it applicable in operations where chip evacuation and tool life depend on directed coolant flow at the cutting zone. The 4 inch projection provides clearance for deep-cavity work or fixtures that require additional reach without the use of extension adapters. Balanced to 30,000 RPM, this holder is compatible with high-speed machining applications common in aerospace, mold and die, and precision part manufacturing.

Key Features

• BT40 taper shank for direct spindle mounting on BT40-equipped machining centers
• 3/16 inch bore accepts small-diameter end mills with precision fit
• TIR of 0.0002 inches ensures low runout for accurate cuts and extended tool life
• Through-coolant compatible via through-spindle and DIN flange coolant delivery
• Balanced to 30,000 RPM for high-speed machining without vibration-induced error
• M16 x 2.0 drawbar thread for secure, standardized spindle retention

Compatibility

Designed for use with BT40 taper spindle machining centers that support through-spindle or DIN flange coolant delivery and an M16 x 2.0 drawbar thread.

Installation Notes

Installation should be performed by a qualified machinist or CNC setup technician with the machine powered down and the spindle fully de-energized before tooling changes. Use the appropriate BT40 tool setter or holder tightening fixture to torque the drawbar to the machining center manufacturer's specification — do not use impact tools on the drawbar. Verify runout with a dial test indicator after seating the holder to confirm the TIR is within tolerance before initiating a cutting cycle. Inspect coolant passages for obstructions before use if through-coolant operation is required.