Accupro 778402 End Mill Holder HSK63A 5/8 Inch Hole

Product Description

The ACCUPRO 778402 is an HSK63A taper shank end mill holder designed for precision CNC machining applications. It accepts a 5/8-inch tool bore and delivers a 4-inch projection from the spindle face, providing clearance for deep-cavity milling operations. The 1-1/2-inch nose diameter gives the holder a rigid, balanced profile suited for high-speed work. With a Total Indicator Runout (TIR) of 0.003 mm and a balance rating of 20,000 RPM, this holder is built for modern high-speed machining centers where runout and vibration directly affect surface finish and tool life. It weighs 3.5 pounds and does not include through-coolant capability.

This end mill holder is intended for use in CNC machining centers equipped with an HSK63A spindle interface. The HSK63A hollow-shank taper is common in high-speed production environments including aerospace, automotive, and precision mold-and-die shops. The 4-inch projection makes it well suited for applications requiring extended reach without sacrificing rigidity. Installation is handled by CNC setup technicians and toolroom machinists as part of standard tooling changeout procedures.

Key Features

• HSK63A hollow-shank taper interface for high-speed spindle compatibility
• 5/8-inch bore accommodates standard end mill shank sizes
• 4-inch projection provides extended reach for deep-cavity operations
• TIR of 0.003 mm supports tight-tolerance finishing passes
• Balanced to 20,000 RPM for stable high-speed machining
• 1-1/2-inch nose diameter for rigid tool support

Compatibility

Designed for use in CNC machining centers with an HSK63A spindle interface accepting standard end mill shanks of 5/8 inch diameter.

Installation Notes

Installation should be performed by a qualified CNC machinist or toolroom technician following the machine tool manufacturer's toolholder torque and clamping procedures. Always power down and lock out the spindle before inserting or removing the holder. Inspect the HSK63A taper bore and spindle taper for chips, burrs, or contamination before seating the holder. Verify runout with a dial indicator after installation to confirm TIR is within the application tolerance.