Accupro 775356 End Mill Holder R8 Taper Shank 1 Inch

Product Description

The ACCUPRO 775356 is an R8 taper shank end mill holder designed for use in manual and CNC vertical milling machines fitted with an R8 spindle. It accepts end mills with a 1-inch shank diameter and provides a 3.1-inch projection from the gauge line, giving the tool sufficient clearance for a range of milling operations. The holder features a drawbar thread size of 7/16-20, which is standard for R8-spindle machines. Total indicated runout (TIR) is rated at 0.0002 inches, supporting accurate material removal and consistent tool life. Installed by machinists and toolroom technicians, this holder is a direct-mount solution that does not require an intermediate adapter.

This end mill holder is suited for vertical milling machines using the R8 spindle interface, common in Bridgeport-style knee mills and similarly configured manual or light CNC milling centers. The 1-inch bore accommodates large-diameter end mills used in facing, slotting, and profiling operations. The 3.1-inch projection allows clearance over workholding fixtures in many standard setups. No through-spindle coolant port is included, making this holder appropriate for dry cutting or flood coolant environments where coolant is delivered externally.

Key Features

• R8 taper shank for direct spindle mounting without an adapter
• 1-inch bore diameter accommodates large-shank end mills
• 3.1-inch projection provides fixture clearance in typical setups
• TIR of 0.0002 inches supports accurate, repeatable cuts
• 7/16-20 drawbar thread matches standard R8-spindle machines
• No through-coolant port; compatible with external flood coolant delivery

Compatibility

Designed as an OEM-style end mill holder for vertical milling machines equipped with an R8 spindle interface and a 7/16-20 drawbar thread.

Installation Notes

Installation and removal should be performed by a qualified machinist with the machine powered off and the spindle fully stopped. The drawbar must be tightened to the machine manufacturer's specified torque using the correct wrench size for the 7/16-20 thread before spindle operation. Inspect the R8 taper bore and the spindle taper for chips, burrs, or wear before seating the holder. Never run the spindle with a loose or improperly seated drawbar.