A bolt is a form of threaded fastener with an external male thread requiring a matching pre-formed female thread such as a nut. Bolts are very closely related to screws.
![Technische Zeichnung : Schmiedeteile zum Polonceaudach[,] 11600 Spannweite](https://asset.museum-digital.org/berlin/images/201610/200w_31101249770.jpg)
