Bolt/Nut Knobs and Wrench

thingiverse

These knobs utilize a standard 1/4" diameter by 20 tpi bolt or nut and function as a knob that threads over a bolt or a knob that threads through a nut, depending on how you use them. You can secure the bolt hardware with glue, but they've worked perfectly fine for me without it, simply relying on a pressure fit.