Collis Tool 68044 End Mill Holder NMTB40 3/4 Inch Bore

Product Description

The COLLIS TOOL 68044 is an end mill holder designed for use with NMTB40 taper shank spindles on vertical machining centers and knee mills. It accepts end mills with a 3/4 inch bore and provides 2.3125 inches of projection from the spindle nose, giving adequate clearance for a wide range of milling operations. The nose diameter measures 1.875 inches. This holder is a standard toolroom component installed by machinists and CNC setup technicians who require a secure, repeatable tool connection in production and job-shop environments.

This end mill holder is suited for vertical milling machines equipped with NMTB40 spindle tapers, commonly found in manual knee mills and older CNC machining centers. The 3/4 inch bore accommodates straight-shank end mills of that diameter, making it a go-to holder for general-purpose face milling, slotting, and peripheral milling applications. The 5/8-11 drawbar thread matches the standard drawbar specification for NMTB40 machines. Through-coolant is not supported by this holder.

Key Features

• NMTB40 taper shank for direct spindle mounting on compatible machines
• 3/4 inch bore diameter accepts standard straight-shank end mills
• 2.3125 inches of projection for clearance in varied milling setups
• 1.875 inch nose diameter for rigidity and vibration resistance at the tool interface
• 5/8-11 drawbar thread matches NMTB40 machine standard
• No through-coolant - suitable for dry or flood coolant applied externally

Compatibility

Designed for use with NMTB40 taper spindle machines requiring a 3/4 inch bore end mill holder with a 5/8-11 drawbar thread connection.

Installation Notes

Installation is performed by a qualified machinist or CNC setup technician. Power down and lock out the machine spindle before inserting or removing any toolholder. Tighten the drawbar to the machine manufacturer's specified torque and inspect the taper seating surface for chips or debris before engagement. Do not use damaged or worn holders, as improper seating can cause tool runout or ejection during operation.