Magnetic 4mm screw bits holder

thingiverse

Pretty simple design, They are designed to fit a circular magnet 6mm in diameter and 1mm in thickness on the bottom to keep the 4mm bits in place and to allow the holders to nicely stick together. The dimensions should be tight enough but if you want you can add a little drop of superglue to hold the magnets permanently. Remember to put the magnets with the same orientations inside the single holder and flip them from one holder to another in order to make them stick properly. CAD files are included in the download