Collis Tool 75904 End Mill Holder R8 Taper Shank

Product Description

The COLLIS TOOL 75904 is an R8 taper shank end mill holder designed for use in milling machines that accept the R8 spindle standard. It secures end mills with a 3/4 inch hole diameter and provides a 2.375 inch projection from the spindle nose to the tool seat. The nose diameter measures 1.75 inches and the overall length is 6.38 inches. This holder is manufactured for machinists and tool and die professionals who require a rigid, repeatable tool-holding solution for vertical milling operations. The taper shank design delivers direct spindle engagement without a separate adapter.

This end mill holder is suited for vertical knee mills and similar machine tools equipped with an R8 spindle, which is common in manual milling machines found in job shops, maintenance facilities, and machine tool training environments. The 3/4 inch bore accommodates standard end mills and shanks of that diameter. The 2.375 inch projection allows clearance for typical workholding setups. Through-coolant is not supported by this holder, making it appropriate for dry or flood-coolant applications where coolant is directed externally.

Key Features

• R8 taper shank for direct engagement with R8-spindle milling machines
• 3/4 inch hole diameter accepts standard end mill shanks
• 2.375 inch projection provides clearance for common workholding setups
• 1.75 inch nose diameter for stable tool support
• 6.38 inch overall length suits standard knee mill spindle depths
• No through-coolant - compatible with external flood or dry cutting setups

Compatibility

Designed as an OEM-style replacement and standard fitment for vertical milling machines with an R8 spindle taper, accepting end mills and cutting tools with a 3/4 inch straight shank.

Installation Notes

Installation is performed by machinists during tool changes on manual vertical milling machines. Always power down and lock out the machine spindle before inserting or removing the holder. The R8 taper is seated by tightening the drawbar from above the spindle head - do not strike the holder to seat it. Inspect the taper bore and spindle for chips or damage before each use to ensure full contact and safe clamping.