Thumb nuts!

thingiverse

Here are two variants of thumb nuts, one chunky and one slim. These are made primarily for M6 nuts which have 10mm hex sizes, however due to the simplicity of straightforward mathematics you can easily scale these for use with other nuts and bolts! Cheat sheet: M2 - 40% scaling factor M3 - 55% scaling factor M4 - 70% scaling factor M5 - 80% scaling factor M6 - exact fit M7 - 110% scaling factor M8 - 130% scaling factor M10 - 160% scaling factor