New insights into brass nails from the 19th-century Akko Tower Wreck (Israel): Metallurgical characterization

The Akko Tower Wreck is the remains of a 25-m-long merchant brig dated to the first half of the 19th century. During the underwater excavations, 105 brass nails were retrieved from the shipwreck. The nails were divided into two groups based on their microstructure: Type A nails were characterized by Widmanstätten plates, while Type B nails by a dendritic microstructure. In each group there were miscellaneous nails, distinguished by their different shapes. Ten miscellaneous nails were characterized by XRF, light microscopy, SEM-EDS analysis, microhardness measurements, anisotropy of magnetic susceptibility examination, and lead isotope analysis. The brass nails were post-cementation products manufactured by casting. The microstructure combined with the AMS analysis, indicated that Type A nails were of better quality than Type B ones. The lead isotope analysis of the nails suggested that their raw material most likely originated in Great Britain.