Will it fit? Let's check. With these tools you can see what your printer will make before you design holes. Do you need a loose fit? Snug? Hammer fit? Do you want to make a hole that a bolt will thread into? These test sticks go up by .2 mm per hole so you can find any type of fit for any round object from 6 mm to 18 mm. Don't bother printing them till you got your printer dialed in though. Write the sizes on them with a marker. See my other things for my edge fit tests and nut fit tests. This is a tool not a test print.