This 2X2 Gridfinity bin with magnets holds up to 23 long 1/4in hex bits (Note: Do not put the smaller standard size bits in here the hole are fairly deep and they are a pain to take out).

There are 2 different spacing in this bin to allow for the use of lager diameter bits and adapters. The upper spacing has 8 positions with a spacing between centers of 20 mm and 20mm between the 2 rows. The lower spacing has 15 positions with a spacing between centers of 15mm and 13mm between the 3 rows.  

I have uploaded the Fusion360 file as well as STEP and STL incase you want to modify the holder. I made this for the WARRIOR Countersink and Deburring Tool Set, SKU's 61629, 66996 and the WARRIOR Hex Shank Socket Driver Set SKU's 68513, 42191, 63928, 63909 both from Harbor Freight. I also had a Pointed Grinding stone from DeWALT DWA4974 that I wanted to have in this holder as well. Since I uploaded the Fusion360 file this should be fairly easy to change the dimensions to fit your needs.

For settings that I changed for this print check out the 3MF file I uploaded.

The Base for this model was generated using the Fusion 360 Gridfinity plugin from Lev Mishin. For more information on this plugin check out the github and the Autodesk plugin page.

https://github.com/Le0Michine/FusionGridfinityGenerator/tree/master

https://apps.autodesk.com/FUSION/en/Detail/Index?id=7197558650811789&os=Win64&appLang=en

This model was designed to work with the Gridfinity system developed by Zach Freedman https://thangs.com/designer/ZackFreedman