Accupro 775216 BT40 End Mill Holder 1/2 in Through Coolant

Product Description

The ACCUPRO 775216 is a BT40 taper shank end mill holder designed for CNC machining centers requiring precise tool holding and through-coolant capability. The holder accepts a 1/2 inch bore and provides a 2.5 inch projection, positioning the cutting tool at the correct standoff for a wide range of milling operations. A total indicator runout (TIR) of 0.0002 inches ensures tight concentricity, which directly supports surface finish quality and extended tool life. Coolant is delivered through-spindle and via DIN flange, keeping the cutting zone clear of chips and reducing heat at the tool tip. Licensed machinists and CNC setup technicians are the primary installers of this toolholder.

This end mill holder is suited for use on CNC vertical and horizontal machining centers equipped with a BT40 spindle interface. The 2.5 inch projection accommodates workpiece features that require clearance between the spindle nose and the part. The through-coolant design is particularly useful in deep-pocket milling, slotting, and high-speed finishing passes where flood coolant does not reach the cutting edge effectively. The holder is balanced to 30000 RPM, making it appropriate for high-speed machining applications where spindle balance directly affects part quality and spindle bearing life.

Key Features

• BT40 taper shank for direct mounting in BT40-compatible spindles
• 1/2 inch bore diameter accommodates standard end mill shanks
• 2.5 inch projection for workpiece clearance in deep-feature milling
• TIR of 0.0002 inches for precise concentricity and consistent tool performance
• Through-spindle and DIN flange coolant delivery for effective chip evacuation and heat control
• Balanced to 30000 RPM for high-speed machining compatibility

Compatibility

Designed for use in CNC machining centers with a BT40 spindle taper interface. The M16 x 2.0 drawbar thread must match the machine spindle drawbar for proper retention.

Installation Notes

Installation is performed by a qualified CNC machinist or setup technician. Power down and lock out the machining center before inserting or removing toolholders from the spindle. Confirm the drawbar thread engagement and retention force meet machine builder specifications before running the spindle. Inspect the taper shank and spindle bore for nicks, chips, or contamination prior to assembly, as surface defects will increase runout and reduce holding force.