Round & Hex Hole Sizers

These sizing tools have holes with specific designed sizes. Print them out with your favorite print settings and use them to find the proper design size to fit your round or hex shaped parts. Especially good for determining the design size of holes for screws, bolts, nuts, shafts, etc.

3D printers usually make holes that are a bit smaller than the designed size. Use these tools to find the designed size that fits your part, then use that size in your design. For example, when I want to design a clearance hole for a screw, I find the hole in the tool that has the fit I want for the screw, then use the designed size of the hole in the new part design. The result is the fit expected, as long as you use the same printer settings for these tools and your part.

When you want more precision, e.g., if you find that one hole is too small and the next size up is too large, you can splint the difference (some guesswork), adding hundredths of a millimeter to the smaller hole size and use th