## 5 Discussion
The XRF analysis of the winch shaft, the heart-shaped shackle, and the deadeye strap with a futtock plate, has shown that they were wrought iron products mainly composed of iron (98.8-99.9 wt% Fe), with small additions of other elements, including less than 1 wt% of Si, P, S, Mn, and Ti (Table 2). For comparison, the wrought iron deadeye No. 163B revealed a composition of 97.6-99.5 wt% Fe, up to 1.3 wt% Si, 0.3-0.9 wt% P, up to 0.6 wt% S, up to 0.7 wt% Al, and up to 0.2 wt% Cu and Mn [9]. The wrought iron ship's bolt examined by [PERSON] et al. (2017) was composed of 98.5-99.3 wt% Fe, 0.3-0.9 wt% Si, up to 0.5 wt% P, up to 0.1 wt% S, and up to 0.2 wt% Cu and Mn [9]. The wrought iron anchor chain links also revealed a similar composition [12]. The SEM-EDS analysis of the winch shaft, the heart-shaped shackle, and the deadeye strap with a futtock plate, detected similar results to the XRF analysis, with a composition of 96.3-99.8 wt% Fe and less than 1 wt% of Si, P, S, and Mn (Table 3). For comparison, the composition of a typical wrought iron link with embedded inclusion particles (part of the anchor chain segment), according to the SEM-EDS analysis, was 95.6 wt% Fe, 2.9 wt% O, 0.5 wt% Si, 0.3 wt% P, 0.4 wt% Mn, 0.2 wt% Ca, and 0.1 wt% Mg [12]. SEM observation of the wrought iron objects revealed the presence of one-phase glassy fayalite slag inclusions, two-phase slag inclusions of the wustite phase surrounded by a glassy phase matrix, and three-phase slag inclusions of wustite and fayalite laths surrounded by a glassy phase matrix (Figures 6-13 and Supplementary Material Figures S11, S14-S16, S19 and S22). Similar inclusions were also observed in the metallographic samples of the wrought iron deadeye No. 163B [9; 19], deadeye 164 chain links [19], and the wrought iron anchor chain links [12], which were all retrieved from the Akko Tower shipwreck. The winch drum, the stud-link chain controller, and the anchor chain link stud were all made of grey cast iron with a similar elemental composition and microstructure, which indicates high-quality production and standardisation of the raw material. The microstructure and composition are comparable to pig iron produced using the coke-fuelled blast furnace in Europe in the nineteenth century [46]. The winch shaft, heart-shaped shackle, deadeye strap with a futtock plate, deadeye No. 163B [9], and the chain link [12] were all made of wrought iron made by refining pig iron, with a similar elemental composition and microstructure, which again indicates a high-quality production and standardisation of the raw metal. The need for metal standardisation arose during the First Industrial Revolution [47]. Most structural ferrous systems during the mid-nineteenth century used a combination of wrought iron and cast iron based on engineering considerations to resist compressive and tensile stresses as appropriate [46]. Wrought iron was chosen because of its weldability, plasticity, and impact resistance [12]. Based on the composition, microstructure, and manufacturing technologies of the grey cast iron and wrought iron objects retrieved from the Akko Tower shipwreck, it is proposed that they were manufactured in the middle of the nineteenth century [12; 45; 46]. This dating agrees well with the dating of the ship [1]. The high quality of the ferrous items retrieved from this shipwreck and their microstructures and compositions indicated that they were all manufactured according to controlled processes and standards at the same workshop and belonged to the original ship.