Collis Tool 75901 End Mill Holder R8 Taper Shank

Product Description

The COLLIS TOOL 75901 is an R8 taper shank end mill holder designed for use in manual and CNC knee mills, Bridgeport-style machines, and other equipment built around the R8 spindle standard. It accepts a 3/8 inch bore and provides a 1.41 inch projection from the spindle face to the cutting tool, keeping the tool close to the spindle for improved rigidity and reduced deflection. The nose diameter measures 1 inch. Machinists and toolroom technicians install this holder as part of the standard R8 tooling setup in general-purpose milling operations. Total weight is 1.02 pounds.

This end mill holder fits mills equipped with an R8 spindle taper, which is the most common spindle configuration found in manual knee mills and light CNC knee-style machines in job shops and maintenance departments. It is suited for holding straight-shank end mills with a 3/8 inch shank diameter. The 5.41 inch overall length and 1.41 inch projection make this holder appropriate for general roughing and finishing passes where minimal tool overhang is preferred. No through-coolant capability is present on this holder.

Key Features

• R8 taper shank for direct fit in R8-spindle knee mills
• 3/8 inch bore accommodates standard 3/8 inch shank end mills
• 1.41 inch projection minimizes tool overhang and deflection
• 1 inch nose diameter for solid clamping rigidity
• 5.41 inch overall length suits standard milling setups
• No through-coolant - suited for dry or flood-coolant-from-outside applications

Compatibility

Designed as an OEM-style tooling holder for milling machines equipped with an R8 taper spindle, accepting 3/8 inch straight-shank end mills.

Installation Notes

Installation should be performed by a qualified machinist or toolroom technician with the machine powered down and the spindle locked. The R8 taper must be clean and free of chips or burrs before seating the holder. Use the appropriate drawbar and torque the drawbar by hand plus a controlled wrench turn per the machine manufacturer's guidance - do not over-torque. Verify tool runout with a dial indicator before commencing any cut.