Tool holder insert MT3 (Morse Taper 3)

This is a printable insert for 35mm (1-3/8") square mild steel tubing. When it comes to heavy tools, a tool holder made of steel is a great option. I've made this insert so that You can click into place in the steel tube. 

Print upside down solid with no support.

Design Your own holders out of square mild steel tubing and use the insert for MT3 tooling.