MT4 ER-40 Collet Chuck | Morse Taper 4 for Milling Machine | M16 Drawbar | 3900-5079

MT4 (Morse Taper 4) to ER-40 Collet Chuck for Milling (MPN: 3900-5079)

This listing is for a high-precision, MT4 ER-40 Collet Chuck designed specifically for milling machines and mill-drills. This is the single best upgrade for any mill with an MT4 spindle, allowing you to use the versatile ER-40 collet system for holding end mills, drills, and other tooling.

Critical Technical Feature: Unlike cheaper tang-end (lathe-style) adapters, this chuck features an 5/8″-11 Threaded Drawbar End . This allows you to pull the chuck securely into the machine’s spindle, providing maximum rigidity and preventing the tool from pulling out during heavy cuts (like climb milling).

Technical Specifications & Improvements

• Spindle Taper: MT4 (Morse Taper #4)

• Collet System: ER-40 (Holds a wide range of tools, 1/8″ – 1″)

• Drawbar Thread: 5/8″-11 Threaded Drawbar End

• MPN: 3900-5079

• Accuracy: Precision ground for a concentricity of 0.0002″ T.I.R.

• Material: Fully hardened and ground alloy steel for durability and low runout.

• Includes: (1) MT4 ER-40 Chuck Body, (1) ER-40 Collet Nut

• Note: Wrench and ER-40 collets are not included.

Why Choose This ER-40 Chuck?

1. Milling Ready: The drawbar end makes it safe and rigid for milling operations.

2. Superior Grip: The ER-40 collet system offers a wider clamping range and 8° taper for a much stronger grip than standard MT collets.

3. Versatility: This one chuck allows you to hold any metric or imperial tool size from 1/8″ to 1″ (with the proper collet set).

Compatibility Check

Please verify your machine’s drawbar thread is 5/8″-11 before purchasing. This chuck is for MT4 spindles on milling machines, not for lathe tailstocks.