Bolt & Nut Generator

About Bolt & Nut Generator

Bolt & Nut Generator makes ISO metric bolts from M2 to M24 in coarse and fine pitches and UNC and UNF bolts from #2 to 1 inch, with a hex, socket, pan, countersunk or thumb head and a hex, square or thumb nut. It sizes the thread for a printed part or for steel, prints a long bolt lying down for strength, and a thread test of five nuts tells you the clearance your printer needs.

The full guide: every step with pictures, examples, print settings, fixes and every setting.

Read the Bolt & Nut Generator guide

Frequently asked questions

Which sizes can I make?
ISO metric M2 to M24 with their coarse and fine pitches, UNC and UNF from #2 to 1 inch, each with its standard heads and nuts, or a custom diameter from 2 to 25.4 mm with your own pitch.
What clearance should I use?
0.2 mm suits most printers. For yours, print the thread test: five nuts 0.05 mm apart on one short bolt. Pick the one that turns on by hand without wobbling, and the bolt and nut take its clearance.
Can a printed nut fit a steel bolt?
Yes. Choose Mates with: Steel bolt and only the nut is printed. It takes all the play, plus the hole offset your printer measured in the fit test, so the steel thread goes in.
Should a bolt print upright or lying?
Upright gives the cleanest thread. A long or loaded bolt is far stronger lying on a flat, because its layers then run along it instead of across it; the checks suggest it for a long, thin bolt.
Do the heads need supports?
No. Hex, socket and thumb heads print flat on the bed, the pan head has a 45° chamfer and the countersunk head is a cone. A lying bolt is cut flat on the bed side, so what is left of its round overhangs 45° at most.
Do I need to install anything?
No. Bolt & Nut Generator runs in the browser, and the geometry is built on your computer. It is free; you need a free NabiMakes account to download the files.

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