Selected iron arrowheads and bolts retrieved from the destruction layer of the Crusader castle of Arsur/Arsuf, which was taken down by the Mamluk army (headed by Baybars) in late April 1265, were studied. Being the only site within the boundaries of the Latin Kingdom of Jerusalem that has thus far yielded more than 1200 iron arrowheads, an archaeometallurgical characterization was performed. The aim of this research was to study the warfare methods and manufacturing technologies used by the Mamluk and Crusader armies. Examination included optical microscopy, SEM and SEM–EDS, XPS and microhardness tests. Analysis was performed on both the metallic iron and iron oxides. Ferrous wooden ‘fossils’, which were found on and within the bolts, were dendroarchaeologically tested. The microstructure analyses show that the weapons were made of wrought iron. These results are correlated with the function of the weapons. The different microstructures of the arrowheads and the bolts indicate dissimilar manufacturing processes. The graphitization of the ropes on the bolts and the oxide phases on their surfaces both provide evidence of high-temperature fire. The ropes support the archaeological findings that these devices were used by the Mamluks to set the Crusader castle on fire.