Summary

I bought a Swanlake 20 piece metric and SAE 1/4" hex driver bit nut driver set on Amazon (B0CZDP1NTV) knowing from the reviews that the nut driver bits were good but the plastic storage holder was not, and also knowing that I have CAD and a 3D printer. The original storage required too much of the precious space in my tool bag and the bits are initially way too difficult to remove, requiring pliers, but quickly wearing to become so loose that the bits fall out. I designed a better bit keeper with two overlapping and interleaved rows for maximum space efficiency and I printed it in TPU-LW so the fit is perfect and will stay that way. I designed the bit holder using round holes instead of hexagonal holes so the bits don't need to be aligned to insert them and so they can be inserted to have any markings aligned to make it easier to find the bit you need and to satisfy compulsive tendencies.

The FreeCAD file is provided so this bit holder can easily be modified to fit your needs.

This bit holder is best printed in TPU or TPU-LW. It can be printed in a harder but non-brittle material such as ABS or PETG but the print will probably need to be scaled because the tolerance is much lower with less conforming materials.