Magnetic holder for 10 mini files, for example these. Magnets hold the files to the holder and the holder to something metallic. 

Holes for magnets are parametric, everything up to 8mm x 2mm works. Backside has holes for 16 magnets, use as many as needed depending on strenght of your magnets. Holes have tiny taper and 0.1mm extra tolerance, so input measurements from manufacturer and adjust if needed.

Parameters in f3d for:

• hole diameter
• hole depth
• adjustment for diameter and depth tolerance for front and back

Stl and print profiles have holes for 6mm x 2mm magnets.

Print back side down, I used supports for back side holes but that might not be necessary. Print profiles have supports.