Accupro 778414 End Mill Holder HSK63A 1-1/4 Inches

Product Description

The ACCUPRO 778414 is an end mill holder designed for CNC machining centers that use the HSK63A taper shank interface. It accepts end mills with a 1-1/4 inch bore and provides a 4.5 inch projection from the spindle face to the tool tip. The nose diameter measures 2-1/2 inches. With a TIR of 0.003 mm and a balanced speed rating of 20,000 RPM, this holder is suited for high-speed milling operations where runout control and dynamic balance are critical. It is installed and serviced by CNC machine tool technicians and toolroom machinists.

This end mill holder is intended for use on horizontal and vertical machining centers equipped with HSK63A spindle connections. The HSK63A interface provides a dual-contact, hollow taper fit that performs well at elevated spindle speeds. The 4.5 inch projection makes it a practical choice for applications requiring clearance over fixtures or workpiece features. Through coolant is not supported on this holder.

Key Features

• HSK63A taper shank for dual-contact hollow-taper spindle connection
• 1-1/4 inch bore diameter accommodates standard end mill shanks
• 4.5 inch projection for fixture clearance and deep-reach applications
• TIR of 0.003 mm for precision runout control
• Balanced to 20,000 RPM for high-speed machining compatibility
• No through-coolant — external coolant delivery applies

Compatibility

Designed for use in machining centers equipped with HSK63A spindle interfaces accepting end mill holders with a 1-1/4 inch bore.

Installation Notes

End mill holders should be installed and torqued using the spindle manufacturer's specified clamping procedure and an HSK-compatible tool setter. Always power down and lock out the machine before handling tooling. Inspect the taper bore and spindle socket for chips or contamination before seating the holder. Use a torque wrench and collet nut spanner rated for the holder size — never impact tools on precision toolholders.