Bolt size tester
With this tool I can quickly test a bolt for the diameter and guarantee its going to fit after 3D printing.
The vertical embossed lettering ( which in my photo I painted) is the diameter ( mm) of each center hole and the horizontal number is the diameter (mm) of the inset... to help if your wanting to recess the head.
1st 5 holes have the inset set for 3mm deep.
The rest are 5 mm deep. I skipped a few larger numbers I don't use to cut down on the length.
Hope this helps you to not waste time and plastic!!!
This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/cbEzBU7jpIr