Accupro 775354 End Mill Holder R8 Taper Shank

Product Description

The ACCUPRO 775354 is an R8 taper shank end mill holder designed for use in manual and CNC vertical milling machines equipped with R8 spindles. It accepts a 7/8 inch bore and provides a 2.3 inch projection from the spindle face to the tool tip, giving machinists the clearance needed for a wide range of end mill operations. The holder features a drawbar thread size of 7/16-20, which is the standard thread used on Bridgeport-style and compatible R8 spindle machines. Total Indicated Runout (TIR) is rated at 0.0002 inch, supporting accurate, repeatable cutting performance. Installation is performed by machinists and mill operators as part of standard tooling setup.

This end mill holder is suited for vertical milling applications in job shops, tool rooms, and production environments where R8 tooling is the shop standard. It is used to securely mount end mills with a 7/8 inch shank diameter. The 2.3 inch projection accommodates workpiece clearance requirements common in face milling, profiling, and slotting operations. Through-coolant is not supported on this holder, making it appropriate for dry cutting or flood coolant setups where coolant is delivered externally.

Key Features

• R8 taper shank for compatibility with R8 spindle machines
• 7/8 inch bore diameter accepts standard 7/8 inch shank end mills
• 2.3 inch projection (69.85 mm) provides workpiece clearance for typical milling tasks
• TIR of 0.0002 inch supports precise, low-runout tool holding
• Drawbar thread size of 7/16-20 matches standard R8 spindle drawbar specification
• No through-coolant port; compatible with external flood coolant delivery

Compatibility

Designed as an OEM-style replacement and standard tooling option for vertical milling machines with R8 spindles accepting a 7/16-20 drawbar thread.

Installation Notes

Installation is performed by a machinist or mill operator. Power down and de-energize the milling machine before changing tooling. Secure the end mill in the holder before inserting the assembly into the spindle, then tighten the drawbar to the machine manufacturer's specification using the appropriate wrench. Inspect the bore and taper surfaces for chips or debris before seating the holder to protect TIR performance.