MT5 (Internal) to MT6 (External) Morse Taper Sleeve (MPN: 3900-1856)
This listing is for a heavy-duty, precision-ground MT5 to MT6 Morse Taper sleeve. This is the essential adapter required to mount a tool with a male MT5 shank (like a large drill bit, chuck arbor, or reamer) into a massive machine spindle that accepts a male MT6 taper.
This adapter is intended for large, industrial machinery such as radial arm drill presses, heavy-duty lathes, and horizontal or vertical boring mills.
Technical Specifications & Improvements
MPN: 3900-1856
Internal Taper (Female): MT5 (Morse Taper #5)
External Taper (Male): MT6 (Morse Taper #6)
Quality Enhancement: Hardened & Fully Precision Ground This is not a simple “turned” adapter. This professional-grade sleeve is made from high-grade tool steel which is both hardened and precision ground.
Hardened: Resists wear, nicks, and damage from heavy tool insertion, ensuring a long service life.
Precision Ground (Internal & External): This is the most critical feature. The inside and outside tapers are both ground to a smooth, concentric finish. This ensures a perfect friction fit, eliminates wobble, and guarantees your tool spins with the lowest possible runout (T.I.R.).
Common Applications
Radial Drill Press: Use an MT5 taper-shank drill bit in a large MT6 spindle.
Heavy-Duty Lathe: Mount an MT5 drill chuck arbor or live center in a massive MT6 tailstock.
Boring Mill: Adapt MT5 tooling for use in an MT6 spindle.
Note: This sleeve adapts a smaller MT5 tool to fit into a larger MT6 spindle.





